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1.  The Burden of Invasive Early-Onset Neonatal Sepsis in the United States, 2005–2008 
Background
Sepsis in the first 3 days of life is a leading cause of morbidity and mortality among infants. Group B Streptococcus (GBS), historically the primary cause of early-onset sepsis, has declined through widespread use of intrapartum chemoprophylaxis. We estimated the national burden of invasive early-onset sepsis (EOS) cases and deaths in the era of GBS prevention.
Methods
Population-based surveillance for invasive EOS was conducted in 4 of CDC’s Active Bacterial Core surveillance (ABCs) sites from 2005–2008. We calculated incidence using state and national live birth files. Estimates of the national number of cases and deaths were calculated, standardizing by race and gestational age.
Results
ABCs identified 658 cases of EOS; 72 (10.9%) were fatal. Overall incidence remained stable during the three years (2005:0.77 cases/1,000 live births; 2008:0.76 cases/1,000 live births). GBS (~38%) was the most commonly reported pathogen followed by Escherichia coli (~24%). Black preterm infants had the highest incidence (5.14 cases/1,000 live births) and case fatality (24.4%). Non-black term infants had the lowest incidence (0.40 cases/1,000 live births) and case fatality (1.6%). The estimated national annual burden of EOS was approximately 3,320 cases (95% CI: 3,060–3,580) including 390 deaths (95% CI: 300–490). Among preterm infants, 1,570 cases (95% CI: 1,400–1,770; 47.3% of the overall) and 360 deaths (95% CI: 280–460; 92.3% of the overall) occurred annually.
Conclusions
The burden of invasive early-onset sepsis remains substantial in the era of GBS prevention and disproportionately affects preterm and black infants. Identification of strategies to prevent preterm births is needed to reduce the neonatal sepsis burden.
doi:10.1097/INF.0b013e318223bad2
PMCID: PMC3193564  PMID: 21654548
early-onset; neonatal sepsis; group B Streptococcus; disease burden
2.  The Effect of Changing Patterns of Obstetric Care in Scotland (1980–2004) on Rates of Preterm Birth and Its Neonatal Consequences: Perinatal Database Study 
PLoS Medicine  2009;6(9):e1000153.
Jane Norman and colleagues analyzed linked perinatal surveillance data in Scotland and find that between 1980 and 2004 increases in spontaneous and medically induced preterm births contributed equally to the rising rate of preterm births.
Background
Rates of preterm birth are rising worldwide. Studies from the United States and Latin America suggest that much of this rise relates to increased rates of medically indicated preterm birth. In contrast, European and Australian data suggest that increases in spontaneous preterm labour also play a role. We aimed, in a population-based database of 5 million people, to determine the temporal trends and obstetric antecedents of singleton preterm birth and its associated neonatal mortality and morbidity for the period 1980–2004.
Methods and Findings
There were 1.49 million births in Scotland over the study period, of which 5.8% were preterm. We found a percentage increase in crude rates of both spontaneous preterm birth per 1,000 singleton births (10.7%, p<0.01) and medically indicated preterm births (41.2%, p<0.01), which persisted when adjusted for maternal age at delivery. The greater proportion of spontaneous preterm births meant that the absolute increase in rates of preterm birth in each category were similar. Of specific maternal complications, essential and pregnancy-induced hypertension, pre-eclampsia, and placenta praevia played a decreasing role in preterm birth over the study period, with gestational and pre-existing diabetes playing an increasing role. There was a decline in stillbirth, neonatal, and extended perinatal mortality associated with preterm birth at all gestation over the study period but an increase in the rate of prolonged hospital stay for the neonate. Neonatal mortality improved in all subgroups, regardless of obstetric antecedent of preterm birth or gestational age. In the 28 wk and greater gestational groups we found a reduction in stillbirths and extended perinatal mortality for medically induced but not spontaneous preterm births (in the absence of maternal complications) although at the expense of a longer stay in neonatal intensive care. This improvement in stillbirth and neonatal mortality supports the decision making behind the 34% increase in elective/induced preterm birth in these women. Although improvements in neonatal outcomes overall are welcome, preterm birth still accounts for over 66% of singleton stillbirths, 65% of singleton neonatal deaths, and 67% of infants whose stay in the neonatal unit is “prolonged,” suggesting this condition remains a significant contributor to perinatal mortality and morbidity.
Conclusions
In our population, increases in spontaneous and medically induced preterm births have made equal contributions to the rising rate of preterm birth. Despite improvements in related perinatal mortality, preterm birth remains a major obstetric and neonatal problem, and its frequency is increasing.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks but increasing numbers of babies are being born preterm, before they reach 37 weeks of gestation (gestation is the period during which a baby develops in its mother). Nowadays in the US, for example, more than half a million babies arrive earlier than expected every year (1 in 8 babies). Although improvements in the care of newborn babies (neonatal care) mean that preterm babies are more likely to survive than in the past, preterm birth remains the single biggest cause of infant death in many developed countries, and many preterm babies who survive have long-term health problems and disabilities, particularly those born before 32 weeks of gestation. Preterm births can be spontaneous or medically induced. At present, it impossible to predict which mothers will spontaneously deliver early and there is no effective way to prevent these preterm births; medically induced early labor is undertaken when either the unborn baby or mother would be at risk if the pregnancy continued to full term.
Why Was This Study Done?
Preterm birth rates need to be reduced, but before this can be done it is important to know how the causes of preterm birth, the numbers of preterm stillbirths, and the numbers of preterm babies who die at birth (neonatal deaths) or soon after (perinatal deaths) are changing with time. If, for example, the rise in preterm births is mainly due to an increase in medically induced labor and if this change in practice has reduced neonatal deaths, it would be unwise to try to reduce the preterm birth rate by discouraging medically induced preterm births. So far, data from the US and Latin America suggest that the increase in preterm births in these countries is solely due to increased rates of medically induced preterm births. However, in Europe and Australia, the rate of spontaneous preterm births also seems to be increasing. In this study, the researchers examine the trends over time and causes of preterm birth and of neonatal death and illness in Scotland over a 25-year period.
What Did the Researchers Do and Find?
By searching a Scottish database of linked maternity records and infant health and death records, the researchers identified 1.49 million singleton births that occurred between 1980 and 2004 of which nearly 90,000 were preterm births. Over the study period, the rates of spontaneous and of medically induced preterm births per 1,000 births increased by 10.7% and 41.2%, respectively, but because there were more spontaneous preterm births than medically induced preterm births, the absolute increase in the rates of each type of birth was similar. Several maternal complications including preeclampsia (a condition that causes high blood pressure) and placenta previa (covering of the opening of the cervix by the placenta) played a decreasing role in preterm births over the study period, whereas gestational and preexisting diabetes played an increasing role. Finally, there was a decline in stillbirths and in neonatal and perinatal deaths among preterm babies, although more babies remained in the hospital longer than 7 days after birth. More specifically, after 28 weeks of gestation, stillbirths and perinatal deaths decreased among medically induced preterm births but not among spontaneous preterm births.
What Do These Findings Mean?
These findings indicate that in Scotland between 1980 and 2004, increases in spontaneous and medically induced preterm births contributed equally to the rising rate of preterm births. Importantly, they also show that the increase in induced preterm births helped to reduce stillbirths and neonatal and perinatal deaths, a finding that supports the criteria that clinicians currently use to decide whether to induce an early birth. Nevertheless, preterm births still account for two-thirds of all stillbirths, neonatal deaths, and extended neonatal stays in hospital and thus cause considerable suffering and greatly increase the workload in neonatal units. The rates of such births consequently need to be reduced and, for Scotland at least, ways will have to be found to reduce the rates of both spontaneous and induced preterm births to achieve this goal while continuing to identify those sick babies who need to be delivered early to give them the best chance of survival.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000153
Tommys is a nonprofit organization that funds research and provides information on the causes and prevention of miscarriage, premature birth, and stillbirth
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
The US Centers for Disease Control and Prevention provides information on maternal and infant health (in English and Spanish)
The US National Women's Health Information Center has detailed information about pregnancy, including a section on pregnancy complications
MedlinePlus provides links to other information on premature babies and to information on pregnancy (in English and Spanish)
doi:10.1371/journal.pmed.1000153
PMCID: PMC2740823  PMID: 19771156
3.  Post-neonatal Mortality, Morbidity, and Developmental Outcome after Ultrasound-Dated Preterm Birth in Rural Malawi: A Community-Based Cohort Study 
PLoS Medicine  2011;8(11):e1001121.
Using data collected as a follow-up to a randomized trial, Melissa Gladstone and colleagues show that during the first two years of life, infants born preterm in southern Malawi are disadvantaged in terms of mortality, growth, and development.
Background
Preterm birth is considered to be associated with an estimated 27% of neonatal deaths, the majority in resource-poor countries where rates of prematurity are high. There is no information on medium term outcomes after accurately determined preterm birth in such settings.
Methods and Findings
This community-based stratified cohort study conducted between May–December 2006 in Southern Malawi followed up 840 post-neonatal infants born to mothers who had received antenatal antibiotic prophylaxis/placebo in an attempt to reduce rates of preterm birth (APPLe trial ISRCTN84023116). Gestational age at delivery was based on ultrasound measurement of fetal bi-parietal diameter in early-mid pregnancy. 247 infants born before 37 wk gestation and 593 term infants were assessed at 12, 18, or 24 months. We assessed survival (death), morbidity (reported by carer, admissions, out-patient attendance), growth (weight and height), and development (Ten Question Questionnaire [TQQ] and Malawi Developmental Assessment Tool [MDAT]). Preterm infants were at significantly greater risk of death (hazard ratio 1.79, 95% CI 1.09–2.95). Surviving preterm infants were more likely to be underweight (weight-for-age z score; p<0.001) or wasted (weight-for-length z score; p<0.01) with no effect of gestational age at delivery. Preterm infants more often screened positively for disability on the Ten Question Questionnaire (p = 0.002). They also had higher rates of developmental delay on the MDAT at 18 months (p = 0.009), with gestational age at delivery (p = 0.01) increasing this likelihood. Morbidity—visits to a health centre (93%) and admissions to hospital (22%)—was similar for both groups.
Conclusions
During the first 2 years of life, infants who are born preterm in resource poor countries, continue to be at a disadvantage in terms of mortality, growth, and development. In addition to interventions in the immediate neonatal period, a refocus on early childhood is needed to improve outcomes for infants born preterm in low-income settings.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Being born at term in Africa is not necessarily straightforward. In Malawi, 33 of every 1,000 infants born die in the first 28 days after birth; the lifetime risk for a mother dying during or shortly after pregnancy is one in 36. The comparable figures for the United Kingdom are three infants dying per 1,000 births and a lifetime risk of maternal death of one in 4,700. But for a baby, being born preterm is even more risky and the gap between low- and high-income countries widens still further. According to a World Health Organization report in 2010, a baby born at 32 weeks of gestation (weighing around 2,000 g) in Africa has little chance of survival, while the chances of survival for a baby born at 32 weeks in North America or Europe are similar to one born at term. There are very few data on the longer term outcomes of babies born preterm in Africa and there are multiple challenges involved in gathering such information. As prenatal ultrasound is not routinely available, gestational age is often uncertain. There may be little routine follow-up of preterm babies as is commonplace in high-income countries. Data are needed from recent years that take into account both improvements in perinatal care and adverse factors such as a rising number of infants becoming HIV positive around the time of birth.
Why Was This Study Done?
We could improve outcomes for babies born preterm in sub-Saharan Africa if we understood more about what happens to them after birth. We cannot assume that the progress of these babies will be the same as those born preterm in a high-income country, as the latter group will have received different care, both before and after birth. If we can document the problems that these preterm babies face in a low-income setting, we can consider why they happen and what treatments can be realistically tested in this setting. It is also helpful to establish baseline data so that changes over time can be recorded.
The aim of this study was to document four specific outcomes up to the age of two years, on which there were few data previously from rural sub-Saharan Africa: how many babies survived, visits to a health center and admissions to the hospital, growth, and developmental delay.
What Did the Researchers Do and Find?
The researchers examined a group of babies that had been born to mothers who had taken part in a randomized controlled trial of an antibiotic to prevent preterm birth. The trial had previously shown that the antibiotic (azithromycin) had no effect on how many babies were born preterm or on other measures of the infants' wellbeing, and so the researchers followed up babies from both arms of the trial to look at longer term outcomes. From the original group of 2,297 women who took part in the trial, they compared 247 infants born preterm against 593 term infants randomly chosen as controls, assessed at 12, 18, or 24 months. The majority of the preterm babies who survived past a month of age (all but ten) were born after 32 weeks of gestation. Compared to the babies born at term, the infants born preterm were nearly twice as likely to die subsequently in the next two years, were more likely to be underweight (a third were moderately underweight), and to have higher rates of developmental delay. The commonest causes of death were gastroenteritis, respiratory problems, and malaria. Visits to a health center and admissions to hospital were similar in both groups.
What Do these Findings Mean?
This study documents longer term outcomes of babies born preterm in sub-Saharan Africa in detail for the first time. The strengths of the study include prenatal ultrasound dating and correct adjustment of follow-up age (which takes into account being born before term). Because the researchers defined morbidity using routine health center attendances and self-report of illnesses by parents, this outcome does not seem to have been as useful as the others in differentiating between the preterm and term babies. Better means of measuring morbidity are needed in this setting.
In the developed world, there is considerable investment being made to improve care during pregnancy and in the neonatal period. This investment in care may help by predicting which mothers are more likely to give birth early and preventing preterm birth through drug or other treatments. It is to be hoped that some of the benefit will be transferable to low-income countries. A baby born at 26 weeks' gestation and admitted to a neonatal unit in the United Kingdom has a 67% chance of survival; preterm babies born in sub-Saharan Africa face a starkly contrasting future.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001121.
UNICEF presents useful statistics on mother and child outcomes
The World Health Organization has attempted to analyse preterm birth rates worldwide, including mapping the regional distribution and has also produced practical guides on strategies such as Kangaroo Mother Care, which can be used for the care of preterm infants in low resource settings
Healthy Newborn Network has good information on initiatives taking place to improve neonatal outcomes in low income settings
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on research being conducted into preterm birth
Tommy's is a nonprofit organization that funds research and provides information on the risks and causes of premature birth
doi:10.1371/journal.pmed.1001121
PMCID: PMC3210771  PMID: 22087079
4.  Neonatal infections: group B streptococcus 
BMJ Clinical Evidence  2010;2010:0323.
Introduction
One in four women carry group B streptococci vaginally, which can infect the amniotic fluid even if the membranes are intact, or can infect the baby during delivery, causing sepsis, pneumonia, or meningitis. Very-low-birthweight infants are at much higher risk of infection or mortality, with up to 3% infected, and mortality rates of up to 30% even with immediate antibiotic treatment. Late-onset group B streptococcal infection begins after 7 to 9 days, and usually causes fever or meningitis, but is less often fatal compared with early infection.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of prophylactic treatment of asymptomatic neonates less than 7 days old with known risk factors for group B streptococcal infection? We searched: Medline, Embase, The Cochrane Library and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found 12 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: different antibiotics, monitoring and selective treatment, and routine antibiotic prophylaxis.
Key Points
Early-onset neonatal sepsis, typically caused by group B streptococcal infection, usually begins within 24 hours of birth, affects up to 2 infants per 1000 live births, and leads to death if untreated. One in four women carry group B streptococci vaginally, which can infect the amniotic fluid even if the membranes are intact, or infect the baby during delivery, causing sepsis, pneumonia, or meningitis.Very low-birthweight infants are at much higher risk of infection or mortality, with up to 3% infected, and mortality rates of up to 30%, even with immediate antibiotic treatment.Late-onset group B streptococcal infection begins after 7 to 9 days and usually causes fever or meningitis, but is less often fatal compared with early infection.
Routine antibiotic prophylaxis, either given to asymptomatic infants born to mothers with risk factors for neonatal infection or given to low-birthweight babies after birth, does not seem to be beneficial in reducing neonatal infection or mortality compared with close monitoring and selective antibiotics. We don't know which antibiotic regimen is most effective at preventing group B streptococcal infection in high-risk neonates.
Increasing peripartum antibiotic prophylaxis may be associated with a shift in the pathogens causing neonatal sepsis, with Escherichia coli becoming a more prevalent cause.
PMCID: PMC3217750  PMID: 21418675
5.  The APPLe Study: A Randomized, Community-Based, Placebo-Controlled Trial of Azithromycin for the Prevention of Preterm Birth, with Meta-Analysis 
PLoS Medicine  2009;6(12):e1000191.
In a randomized trial in Malawi of azithromycin versus placebo in over 2,000 pregnant women, Jim Neilson and colleagues show no benefit of azithromycin for a number of outcomes including preterm birth and prenatal death.
Background
Premature birth is the major cause of perinatal mortality and morbidity in both high- and low-income countries. The causes of preterm labour are multiple but infection is important. We have previously described an unusually high incidence of preterm birth (20%) in an ultrasound-dated, rural, pregnant population in Southern Malawi with high burdens of infective morbidity. We have now studied the impact of routine prophylaxis with azithromycin as directly observed, single-dose therapy at two gestational windows to try to decrease the incidence of preterm birth.
Methods and Findings
We randomized 2,297 pregnant women attending three rural and one peri-urban health centres in Southern Malawi to a placebo-controlled trial of oral azithromycin (1 g) given at 16–24 and 28–32 wk gestation. Gestational age was determined by ultrasound before 24 wk. Women and their infants were followed up until 6 wk post delivery. The primary outcome was incidence of preterm delivery, defined as <37 wk. Secondary outcomes were mean gestational age at delivery, perinatal mortality, birthweight, maternal malaria, and anaemia. Analysis was by intention to treat. There were no significant differences in outcome between the azithromycin group (n = 1,096) and the placebo group (n = 1,087) in respect of preterm birth (16.8% versus 17.4%), odds ratio (OR) 0.96, 95% confidence interval (0.76–1.21); mean gestational age at delivery (38.5 versus 38.4 weeks), mean difference 0.16 (−0.08 to 0.40); mean birthweight (3.03 versus 2.99 kg), mean difference 0.04 (−0.005 to 0.08); perinatal deaths (4.3% versus 5.0%), OR 0.85 (0.53–1.38); or maternal malarial parasitaemia (11.5% versus 10.1%), OR 1.11 (0.84–1.49) and anaemia (44.1% versus 41.3%) at 28–32 weeks, OR 1.07 (0.88–1.30). Meta-analysis of the primary outcome results with seven other studies of routine antibiotic prophylaxis in pregnancy (>6,200 pregnancies) shows no effect on preterm birth (relative risk 1.02, 95% confidence interval 0.86–1.22).
Conclusions
This study provides no support for the use of antibiotics as routine prophylaxis to prevent preterm birth in high risk populations; prevention of preterm birth requires alternative strategies.
Trial registration
Current Controlled Trials ISRCTN84023116
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks. Labor that occurs before 37 weeks of gestation (the period during which a baby develops in its mother) is defined as a preterm birth. In industrialized countries, 5%–10% of all births are preterm. Figures for preterm births are harder to obtain for low-income countries because of uncertainties about gestational dates but, in both rich and poor countries, preterm birth is a major cause of infant death and illness around the time of birth. Babies who are born prematurely also often have long-term health problems and disabilities. There are many reasons why some babies are born prematurely. Structural problems such as a weak cervix (the neck of the womb, which dilates during labor to allow the baby to leave the mother's body) can result in a premature delivery, as can pregnancy-induced diabetes, blood-clotting disorders, bacterial infections in the vagina or the womb, and malaria. However, it is impossible to predict which mothers will spontaneously deliver early.
Why Was This Study Done?
At present there is no effective way to prevent premature births. Because infection is often associated with preterm labor and can occur early in pregnancy but remain undetected, one way to reduce the incidence of preterm births may be to give pregnant women antibiotics even when they have no obvious infection (prophylactic antibiotics). In this study, the researchers test this hypothesis by giving the antibiotic azithromycin to pregnant women living in Southern Malawi in a randomized, placebo-controlled trial. One baby in five is born before 37 weeks gestation in Southern Malawi and the women living in this part of sub-Saharan Africa have a high burden of infection. Azithromycin is a safe antibiotic that can treat many of the bacterial infections that have been implicated in preterm birth. It also has some antimalarial activity. In a randomized, placebo-controlled trial, participants are randomly assigned to receive a drug or identical-looking “dummy” tablets (placebo).
What Did the Researchers Do and Find?
The researchers enrolled more than 2,000 pregnant women into the APPLe study (Azithromycin for the Prevention of Preterm Labor) and determined the gestational age of their unborn babies using ultrasound. Half of the women were given an oral dose of azithromycin at 16–24 weeks and at 28–32 weeks gestation. The remaining women were given a placebo at similar times. The mothers and their babies were followed up until 6 weeks after delivery. There was no significant difference in the primary outcome of the study—the incidence of delivery before 37 weeks gestation—between the two groups of women. Secondary outcomes—including mean gestational age at delivery, mean birth weight, and still births and infant deaths within a week of birth—were also similar in the two groups of women. Finally, the researchers did a meta-analysis (a statistical technique that combines the results of several studies) of their study and seven published studies of routine antibiotic prophylaxis in pregnancy, which indicated that the prophylactic use of antibiotics did not alter the risk of preterm birth.
What Do These Findings Mean?
These findings provide no support for the use of antibiotics as prophylaxis to prevent preterm birth. The women included in this study had an unusually high incidence of preterm delivery and a high burden of infection so these findings may not be generalizable. The results of the meta-analysis, however, also provide no support for prophylactic antibiotics. Given that observational data have associated infection with preterm labor, why are the results of the APPLe trial and the meta-analysis negative? One possibility is that different antibiotics or dosing regimens might be more effective. Another possibility is that infection might be a secondary consequence of some other condition that causes preterm birth rather than the primary cause of early delivery. Whatever the reason for the lack of effect of prophylactic antibiotics, the researchers recommend that pregnant women should not be given antibiotics prophylactically to prevent preterm birth particularly since, in a recent study, the babies of women given antibiotics to halt ongoing preterm labor had an increased risk of developmental problems.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000191.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
Tommy's is a nonprofit organization that funds research and provides information on the causes and prevention of miscarriage, premature birth, and stillbirth
The US Centers for Disease Control and Prevention provides information on maternal and infant health (in English and Spanish)
The US National Women's Health Information Center has detailed information about pregnancy (in English and Spanish)
MedlinePlus provides links to other information on premature babies (in English and Spanish)
doi:10.1371/journal.pmed.1000191
PMCID: PMC2776277  PMID: 19956761
6.  Risk of Early-Onset Neonatal Infection with Maternal Infection or Colonization: A Global Systematic Review and Meta-Analysis 
PLoS Medicine  2013;10(8):e1001502.
Grace Chan and coauthors conducted a systematic review and meta-analysis of studies evaluating the risk of neonatal infection or colonization during the first seven days of life among newborns of mothers with bacterial infection or colonization during the intrapartum period.
Please see later in the article for the Editors' Summary
Background
Neonatal infections cause a significant proportion of deaths in the first week of life, yet little is known about risk factors and pathways of transmission for early-onset neonatal sepsis globally. We aimed to estimate the risk of neonatal infection (excluding sexually transmitted diseases [STDs] or congenital infections) in the first seven days of life among newborns of mothers with bacterial infection or colonization during the intrapartum period.
Methods and Findings
We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, and the World Health Organization Regional Databases for studies of maternal infection, vertical transmission, and neonatal infection published from January 1, 1960 to March 30, 2013. Studies were included that reported effect measures on the risk of neonatal infection among newborns exposed to maternal infection. Random effects meta-analyses were used to pool data and calculate the odds ratio estimates of risk of infection. Eighty-three studies met the inclusion criteria. Seven studies (8.4%) were from high neonatal mortality settings. Considerable heterogeneity existed between studies given the various definitions of laboratory-confirmed and clinical signs of infection, as well as for colonization and risk factors. The odds ratio for neonatal lab-confirmed infection among newborns of mothers with lab-confirmed infection was 6.6 (95% CI 3.9–11.2). Newborns of mothers with colonization had a 9.4 (95% CI 3.1–28.5) times higher odds of lab-confirmed infection than newborns of non-colonized mothers. Newborns of mothers with risk factors for infection (defined as prelabour rupture of membranes [PROM], preterm <37 weeks PROM, and prolonged ROM) had a 2.3 (95% CI 1.0–5.4) times higher odds of infection than newborns of mothers without risk factors.
Conclusions
Neonatal infection in the first week of life is associated with maternal infection and colonization. High-quality studies, particularly from settings with high neonatal mortality, are needed to determine whether targeting treatment of maternal infections or colonization, and/or prophylactic antibiotic treatment of newborns of high risk mothers, may prevent a significant proportion of early-onset neonatal sepsis.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Millennium Development Goal 4 (MDG4)—one of eight goals agreed by world leaders in 2000 to eradicate extreme poverty globally—aims to reduce under-five mortality (deaths) to one-third of its 1990 level (12 million deaths). Progress towards reducing child mortality has accelerated recently, but MDG4 is unlikely to be met, partly because of slow progress towards reducing neonatal mortality—deaths during the first 28 days of life. Neonatal deaths now account for a greater proportion of global child deaths than in 1990. Nearly half of the children who die before their fifth birthday die during the neonatal period, with babies born in low-middle-income countries in sub-Saharan Africa and southern Asia being at the highest risk of neonatal death. Bacterial infections such as infections of the bloodstream (bacteremia/sepsis), lungs (pneumonia), and the brain's protective covering (meningitis) are responsible for a quarter of neonatal deaths. Newborns can acquire infections during birth by picking up bacteria (in particular Group B streptococcus or GBS) that are present in their mother's reproductive tract and that may or may not cause disease in the mother. Bacteria colonizing the maternal perineum (the area between the anus and the vagina) can move up the vaginal canal into the amniotic sac (the fluid-filled bag in which the baby develops). Maternal bacteremia is another source of bacterial transmission from mother to fetus. Other risk factors for neonatal infection include pre-labor rupture of the membranes (PROM) of the amniotic sac, preterm PROM, and prolonged rupture of membranes.
Why Was This Study Done?
In high-income settings, prophylactic (preventative) antibiotic treatment during labor (based on microbiological screening or risk factors such as PROM) and early diagnosis and treatment of sepsis in newborn babies has greatly reduced deaths from early-onset neonatal bacterial infection. Yet, relatively little is known about the risk factors and transmission pathways for this condition globally. In this global systematic review and meta-analysis, the researchers estimate the risk of neonatal bacterial infections (excluding sexually transmitted diseases) among newborns of mothers with bacterial infection or colonization around the time of birth. A systematic review uses predefined criteria to identify all the research on a given topic; meta-analysis is a statistical method for combining the results of several studies.
What Did the Researchers Do and Find?
The researchers identified 83 studies (only seven of which were undertaken in settings with high neonatal mortality) that included data on laboratory-confirmed maternal infection, maternal infection indicated by clinical signs and symptoms, maternal colonization (positive bacterial cultures from the reproductive tract without any signs or symptoms of infection), or risk factors for infection such as PROM and data on neonatal infection (laboratory-confirmed or clinically indicated) or colonization. Because different studies used different definitions for infection and colonization, the researchers pooled the data from subsets of the studies using random effects meta-analysis, which allows for heterogeneity (inconsistencies) between studies. Newborns of mothers with laboratory-confirmed infection had a 6.6-fold higher risk of laboratory-confirmed infection than newborns born to mothers without laboratory-confirmed infection. Newborns of mothers with bacterial colonization had a 9.4-fold higher risk of laboratory-confirmed infection than newborns of non-colonized mothers. Finally, compared to newborns of mothers without risk factors for infection, newborns of mothers with PROM or other risk factors had a 2.3-fold higher risk of infection.
What Do These Findings Mean?
These findings indicate that an increased risk of early-onset neonatal infection is associated with maternal infection and maternal colonization and provide some quantification of the excess risk. Because all the studies were facility-based and mostly from urban settings in high-income countries, these findings provide no information about the risk of neonatal infection among home births, rural births or births at community facilities in low-income countries, which limits their generalizability. Other aspects of the studies included in this systematic review and meta-analysis are also likely to limit the accuracy of the findings. Nevertheless, these findings suggest that better diagnosis and treatment of maternal infections and colonization in low- to middle-income countries where neonatal mortality is high might substantially reduce the incidence of neonatal infections and that the development of a simple algorithm that combines clinical signs and risk factors to diagnose maternal infections might be useful in regions where laboratory facilities are unavailable. Moreover, they highlight the need for more studies of maternal and neonatal infection and colonization in resource-poor settings with high neonatal mortality.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001502.
The United Nations Childrens Fund (UNICEF) works for children's rights, survival, development, and protection around the world; it provides information on Millennium Development Goal 4 and its Childinfo website provides detailed statistics about neonatal survival and health; its Committing to Child Survival: a Promise Renewed webpage includes links to its 2012 progress report and to a video about how new health centers are helping India battle high neonatal death rates
The World Health Organization has information about Millennium Development Goal 4 and about newborn health (some information in several languages)
Countdown to 2015 provides additional information on maternal, newborn, and child survival, including its 2012 report Building a Future for Women and Children
Kidshealth, a resource provided by the not-for-profit Nemours Foundation, has information on neonatal infections for parents (in English and Spanish)
The MedlinePlus Encyclopedia has a page on neonatal sepsis (in English and Spanish)
A personal story about fatal neonatal bacterial meningitis is available on the website of Meningitis UK, a not-for profit organization; the site also includes a survivor story
doi:10.1371/journal.pmed.1001502
PMCID: PMC3747995  PMID: 23976885
7.  Preterm Birth and Childhood Wheezing Disorders: A Systematic Review and Meta-Analysis 
PLoS Medicine  2014;11(1):e1001596.
In a systematic review and meta-analysis, Jasper Been and colleagues investigate the association between preterm birth and the development of wheezing disorders in childhood.
Please see later in the article for the Editors' Summary
Background
Accumulating evidence implicates early life factors in the aetiology of non-communicable diseases, including asthma/wheezing disorders. We undertook a systematic review investigating risks of asthma/wheezing disorders in children born preterm, including the increasing numbers who, as a result of advances in neonatal care, now survive very preterm birth.
Methods and Findings
Two reviewers independently searched seven online databases for contemporaneous (1 January 1995–23 September 2013) epidemiological studies investigating the association between preterm birth and asthma/wheezing disorders. Additional studies were identified through reference and citation searches, and contacting international experts. Quality appraisal was undertaken using the Effective Public Health Practice Project instrument. We pooled unadjusted and adjusted effect estimates using random-effects meta-analysis, investigated “dose–response” associations, and undertook subgroup, sensitivity, and meta-regression analyses to assess the robustness of associations.
We identified 42 eligible studies from six continents. Twelve were excluded for population overlap, leaving 30 unique studies involving 1,543,639 children. Preterm birth was associated with an increased risk of wheezing disorders in unadjusted (13.7% versus 8.3%; odds ratio [OR] 1.71, 95% CI 1.57–1.87; 26 studies including 1,500,916 children) and adjusted analyses (OR 1.46, 95% CI 1.29–1.65; 17 studies including 874,710 children). The risk was particularly high among children born very preterm (<32 wk gestation; unadjusted: OR 3.00, 95% CI 2.61–3.44; adjusted: OR 2.81, 95% CI 2.55–3.12). Findings were most pronounced for studies with low risk of bias and were consistent across sensitivity analyses. The estimated population-attributable risk of preterm birth for childhood wheezing disorders was ≥3.1%.
Key limitations related to the paucity of data from low- and middle-income countries, and risk of residual confounding.
Conclusions
There is compelling evidence that preterm birth—particularly very preterm birth—increases the risk of asthma. Given the projected global increases in children surviving preterm births, research now needs to focus on understanding underlying mechanisms, and then to translate these insights into the development of preventive interventions.
Review Registration
PROSPERO CRD42013004965
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last around 40 weeks, but worldwide, more than 11% of babies are born before 37 weeks of gestation (the period during which a baby develops in its mother's womb). Preterm birth is a major cause of infant death—more than 1 million babies die annually from preterm birth complications—and the number of preterm births is increasing globally. Multiple pregnancies, infections, and chronic (long-term) maternal conditions such as diabetes can all cause premature birth, but the cause of many preterm births is unknown. The most obvious immediate complication that is associated with preterm birth is respiratory distress syndrome. This breathing problem, which is more common in early preterm babies than in near-term babies, occurs because the lungs of premature babies are structurally immature and lack pulmonary surfactant, a unique mixture of lipids and proteins that coats the inner lining of the lungs and helps to prevent the collapse of the small air sacs in the lungs that absorb oxygen from the air. Consequently, preterm babies often need help with their breathing and oxygen supplementation.
Why Was This Study Done?
Improvements in the management of prematurity mean that more preterm babies survive today than in the past. However, accumulating evidence suggests that early life events are involved in the subsequent development of non-communicable diseases (non-infectious chronic diseases). Given the increasing burden of preterm birth, a better understanding of the long-term effects of preterm birth is essential. Here, the researchers investigate the risks of asthma and wheezing disorders in children who are born preterm by undertaking a systematic review (a study that uses predefined criteria to identify all the research on a given topic) and a meta-analysis (a statistical method for combining the results of several studies). Asthma is a chronic condition that is caused by inflammation of the airways. In people with asthma, the airways can react very strongly to allergens such as animal fur and to irritants such as cigarette smoke. Exercise, cold air, and infections can also trigger asthma attacks, which can sometimes be fatal. The symptoms of asthma include wheezing (a high-pitched whistling sound during breathing), coughing, chest tightness, and shortness of breath. Asthma cannot be cured, but drugs can relieve its symptoms and prevent acute asthma attacks.
What Did the Researchers Do and Find?
The researchers identified 30 studies undertaken between 1995 and the present (a time span chosen to allow for recent changes in the management of prematurity) that investigated the association between preterm birth and asthma/wheezing disorders in more than 1.5 million children. Across the studies, 13.7% of preterm babies developed asthma/wheezing disorders during childhood, compared to only 8.3% of babies born at term. Thus, the risk of preterm babies developing asthma or a wheezing disorder during childhood was 1.71 times higher than the risk of term babies developing these conditions (an unadjusted odds ratio [OR] of 1.71). In analyses that allowed for confounding factors—other factors that affect the risk of developing asthma/wheezing disorders such as maternal smoking—the risk of preterm babies developing asthma or a wheezing disorder during childhood was 1.46 times higher than that of babies born at term (an adjusted OR of 1.46). Notably, compared to children born at term, children born very early (before 32 weeks of gestation) had about three times the risk of developing asthma/wheezing disorders in unadjusted and adjusted analyses. Finally, the population-attributable risk of preterm birth for childhood wheezing disorders was more than 3.1%. That is, if no preterm births had occurred, there would have been more than a 3.1% reduction in childhood wheezing disorders.
What Do These Findings Mean?
These findings strongly suggest that preterm birth increases the risk of asthma and wheezing disorders during childhood and that the risk of asthma/wheezing disorders increases as the degree of prematurity increases. The accuracy of these findings may be affected, however, by residual confounding. That is, preterm children may share other, unknown characteristics that increase their risk of developing asthma/wheezing disorders. Moreover, the generalizability of these findings is limited by the lack of data from low- and middle-income countries. However, given the projected global increases in children surviving preterm births, these findings highlight the need to undertake research into the mechanisms underlying the association between preterm birth and asthma/wheezing disorders and the need to develop appropriate preventative and therapeutic measures.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001596.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
Nemours, another nonprofit organization for child health, also provides information (in English and Spanish) on premature babies and on asthma (including personal stories)
The UK National Health Service Choices website provides information about premature labor and birth and a real story about having a preterm baby; it provides information about asthma in children (including real stories)
The MedlinePlus Encyclopedia has pages on preterm birth, asthma, asthma in children, and wheezing (in English and Spanish); MedlinePlus provides links to further information on premature birth, asthma, and asthma in children (in English and Spanish)
doi:10.1371/journal.pmed.1001596
PMCID: PMC3904844  PMID: 24492409
8.  HIV-1 Drug Resistance Emergence among Breastfeeding Infants Born to HIV-Infected Mothers during a Single-Arm Trial of Triple-Antiretroviral Prophylaxis for Prevention of Mother-To-Child Transmission: A Secondary Analysis 
PLoS Medicine  2011;8(3):e1000430.
Analysis of a substudy of the Kisumu breastfeeding trial by Clement Zeh and colleagues reveals the emergence of HIV drug resistance in HIV-positive infants born to HIV-infected mothers treated with antiretroviral drugs.
Background
Nevirapine and lamivudine given to mothers are transmitted to infants via breastfeeding in quantities sufficient to have biologic effects on the virus; this may lead to an increased risk of a breastfed infant's development of resistance to maternal antiretrovirals. The Kisumu Breastfeeding Study (KiBS), a single-arm open-label prevention of mother-to-child HIV transmission (PMTCT) trial, assessed the safety and efficacy of zidovudine, lamivudine, and either nevirapine or nelfinavir given to HIV-infected women from 34 wk gestation through 6 mo of breastfeeding. Here, we present findings from a KiBS trial secondary analysis that evaluated the emergence of maternal ARV-associated resistance among 32 HIV-infected breastfed infants.
Methods and Findings
All infants in the cohort were tested for HIV infection using DNA PCR at multiple study visits during the 24 mo of the study, and plasma RNA viral load for all HIV-PCR–positive infants was evaluated retrospectively. Specimens from mothers and infants with viral load >1,000 copies/ml were tested for HIV drug resistance mutations. Overall, 32 infants were HIV infected by 24 mo of age, and of this group, 24 (75%) infants were HIV infected by 6 mo of age. Of the 24 infants infected by 6 mo, nine were born to mothers on a nelfinavir-based regimen, whereas the remaining 15 were born to mothers on a nevirapine-based regimen. All infants were also given single-dose nevirapine within 48 hours of birth. We detected genotypic resistance mutations in none of eight infants who were HIV-PCR positive by 2 wk of age (specimens from six infants were not amplifiable), for 30% (6/20) at 6 wk, 63% (14/22) positive at 14 wk, and 67% (16/24) at 6 mo post partum. Among the 16 infants with resistance mutations by 6 mo post partum, the common mutations were M184V and K103N, conferring resistance to lamivudine and nevirapine, respectively. Genotypic resistance was detected among 9/9 (100%) and 7/15 (47%) infected infants whose mothers were on nelfinavir and nevirapine, respectively. No mutations were detected among the eight infants infected after the breastfeeding period (age 6 mo).
Conclusions
Emergence of HIV drug resistance mutations in HIV-infected infants occurred between 2 wk and 6 mo post partum, most likely because of exposure to maternal ARV drugs through breast milk. Our findings may impact the choice of regimen for ARV treatment of HIV-infected breastfeeding mothers and their infected infants.
Trial Registration
ClinicalTrials.gov NCT00146380
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Globally, more than 2 million children are infected with the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS), and half a million children are newly infected every year. These infections are mainly the result of mother-to-child transmission (MTCT) of HIV during pregnancy, labor and delivery, or through breastfeeding. MTCT can be greatly reduced by treating HIV-positive mothers and their babies with antiretroviral drugs (ARVs). Without ARVs, up to half of babies born to HIV-positive mothers become infected with HIV. This rate of transmission falls to below 5% if a combination of three ARVs is given to the mother throughout pregnancy. Unfortunately, this triple-ARV therapy is too expensive for use in the resource-limited countries where most MTCT occurs. Instead, many such countries have introduced simpler, shorter ARV regimens such as a daily dose of zidovudine (a nucleoside reverse transcriptase inhibitor or NRTI) given to HIV-positive women during late pregnancy coupled with single-dose nevirapine (a non-nucleoside reverse transcriptase inhibitor or NNRTI) at the onset of labor, zidovudine and lamivudine (another NRTI) during labor and delivery, and single-dose nevirapine given to the baby at birth.
Why Was This Study Done?
More than 95% of HIV-exposed children are born in resource-limited settings where breastfeeding is the norm and is crucial for child survival even though it poses a risk of HIV transmission. Consequently, several recent studies have investigated whether MTCT can be further reduced by giving the mother ARVs while she is breastfeeding. In the Kisumu Breastfeeding Study (KiBS), for example, researchers assessed the effects of giving zidovudine, lamivudine, and either nevirapine or nelfinavir (a protease inhibitor) to HIV-infected women from 34 weeks of pregnancy through 6 months of breastfeeding. The results of KiBS indicate that this approach might be a safe, feasible way to reduce MTCT (see the accompanying paper by Thomas and colleagues). However, low amounts of nevirapine and lamivudine are transferred from mother to infant in breast milk and this exposure to ARVs could induce the development of resistance to ARVs among HIV-infected infants. In this KiBS substudy, the researchers investigate whether HIV drug resistance emerged in any of the HIV-positive infants in the parent study.
What Did the Researchers Do and Find?
In KiBS, 32 infants were HIV-positive at 24 months old; 24 were HIV-positive at 6 months old when their mothers stopped taking ARVs and when breastfeeding was supposed to stop. The researchers analyzed blood samples taken from these infants at various ages and from their mothers for the presence of HIV drug resistance mutations (DNA changes that make HIV resistant to killing by ARVs). They detected no resistance mutations in samples taken from 2-week old HIV-positive infants or from the infants who became infected after the age of 6 months. However, they found resistance mutations in a third and two-thirds of samples taken from 6-week and 6-month old HIV-positive infants, respectively. The commonest mutations conferred resistance to lamivudine and nevirapine. Moreover, resistance mutations were present in samples taken from all the HIV-positive infants whose mothers who had received nelfinavir but in only half those taken from infants whose mothers who had received nevirapine. Finally, most of the mothers of HIV-positive infants had no HIV drug resistance mutations, and only one mother-infant pair had an overlapping pattern of HIV drug resistance mutations.
What Do These Findings Mean?
These findings indicate that, in this KiBS substudy, the emergence of HIV drug resistance mutations in HIV-infected infants whose mothers were receiving ARVs occurred between 2 weeks and 6 months after birth. The pattern of mutations suggests that drug resistance most likely arose through exposure of the infants to low levels of ARVs in breast milk rather than through MTCT of drug-resistant virus. These findings need confirming but suggest that infants exposed to ARVs through breast milk—a situation that may become increasingly common given the reduction in MTCT seen in KiBS and other similar trials—should be carefully monitored for HIV infection. Providers should consider the mothers' regimen when choosing treatment for infants who are found to be HIV-infected despite maternal triple drug prophylaxis. Infants exposed to a maternal regimen with NNRTI drugs should receive first-line therapy with lopinavir/ritonavir, a protease inhibitor. The significance of the NRTI mutations such as M184V with regard to response to therapy needs further evaluation. The M184V mutation may result in hypersensitization to other NRTI drugs and delay or reverse zidovudine resistance. Given the limited availability of alternative drugs for infants in resource-limited settings, provision of the standard WHO-recommended first-line NRTI backbone, which includes 3TC, with enhanced monitoring of the infant to ensure virologic suppression, could be considered. Such an approach should reduce both illness and morbidity among infants who become HIV positive through breastfeeding.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/ 10.1371/journal.pmed.1000430.
The accompanying PLoS Medicine Research article by Thomas and colleagues describes the primary findings of the Kisumu Breastfeeding Study
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
HIV InSite has comprehensive information on HIV/AIDS
Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including information on children, HIV, and AIDS and on preventing mother-to-child transmission of HIV (in English and Spanish)
UNICEF also has information about children and HIV and AIDS (in several languages)
The World Health organization has information on mother-to-child transmission of HIV (in several languages), and guidance on the use of ARVs for preventing MTCT
doi:10.1371/journal.pmed.1000430
PMCID: PMC3066134  PMID: 21468304
9.  Chorioamnionitis and Early Childhood Outcomes among Extremely Low-Gestational-Age Neonates 
JAMA pediatrics  2014;168(2):137-147.
Importance
Chorioamnionitis is strongly linked to preterm birth and to neonatal infection. The association between histological and clinical chorioamnionitis and cognitive, behavioral and neurodevelopmental outcomes among extremely preterm neonates is less clear. We evaluated the impact of chorioamnionitis on 18-22 month neurodevelopmental outcomes in a contemporary cohort of extremely preterm neonates.
Objective
To compare the neonatal and neurodevelopmental outcomes of three groups of extremely-low-gestational-age infants with increasing exposure to perinatal inflammation: no chorioamnionitis, histological chorioamnionitis alone, or histological plus clinical chorioamnionitis.
Design
Longitudinal observational study.
Setting
Sixteen centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network.
Participants
2390 extremely preterm infants born <27 weeks' gestational age between January 1, 2006 and December 31, 2008 with placental histopathology and 18-22 months' corrected age follow-up data were eligible.
Main exposure
Chorioamnionitis
Main Outcome Measures
Outcomes included cerebral palsy, gross motor functional limitation, behavioral scores (according to the Brief Infant-Toddler Social and Emotional Assessment), cognitive and language scores (according to the Bayley Scales of Infant Development, 3rd-Edition) and composite measures of death/neurodevelopmental impairment. Multivariable logistic and linear regression models were developed to assess the association between chorioamnionitis and outcomes while controlling for important variables known at birth.
Results
Neonates exposed to chorioamnionitis had a lower gestational age (GA) and had higher rates of early-onset sepsis and severe periventricular-intraventricular hemorrhage as compared with unexposed neonates. In multivariable models evaluating death and neurodevelopmental outcomes, inclusion of gestational age in the model diminished the association between chorioamnionitis and adverse outcomes. Still, histological+clinical chorioamnionitis was associated with increased risk of cognitive impairment as compared with no chorioamnionitis (Adjusted OR 2.4, [1.3- 4.3] without GA; Adjusted OR 2.0, [1.1-3.6] with GA as a covariate). Histological chorioamnionitis alone was associated with lower odds of death/neurodevelopmental impairment as compared with histological+clinical chorioamnionitis (Adjusted OR 0.68, [0.52-0.89] without GA; 0.66, [0.49-0.89] with GA). Risk of behavioral problems did not differ statistically between groups.
Conclusions and Relevance
Antenatal exposure to chorioamnionitis is associated with altered odds of cognitive impairment and death/neurodevelopmental impairment in extremely preterm infants.
doi:10.1001/jamapediatrics.2013.4248
PMCID: PMC4219500  PMID: 24378638
chorioamnionitis; preterm; neurodevelopmental impairment; outcome
10.  Three Postpartum Antiretroviral Regimens to Prevent Intrapartum HIV Infection 
The New England journal of medicine  2012;366(25):2368-2379.
Background
The safety and efficacy of adding antiretroviral drugs to standard zidovudine prophylaxis in infants of mothers with human immunodeficiency virus (HIV) infection who did not receive antenatal antiretroviral therapy (ART) because of late identification are unclear. We evaluated three ART regimens in such infants.
Methods
Within 48 hours after their birth, we randomly assigned formula-fed infants born to women with a peripartum diagnosis of HIV type 1 (HIV-1) infection to one of three regimens: zidovudine for 6 weeks (zidovudine-alone group), zidovudine for 6 weeks plus three doses of nevirapine during the first 8 days of life (two-drug group), or zidovudine for 6 weeks plus nelfinavir and lamivudine for 2 weeks (three-drug group). The primary outcome was HIV-1 infection at 3 months in infants uninfected at birth.
Results
A total of 1684 infants were enrolled in the Americas and South Africa (566 in the zidovudine-alone group, 562 in the two-drug group, and 556 in the three-drug group). The overall rate of in utero transmission of HIV-1 on the basis of Kaplan–Meier estimates was 5.7% (93 infants), with no significant differences among the groups. Intra-partum transmission occurred in 24 infants in the zidovudine-alone group (4.8%; 95% confidence interval [CI], 3.2 to 7.1), as compared with 11 infants in the two-drug group (2.2%; 95% CI, 1.2 to 3.9; P = 0.046) and 12 in the three-drug group (2.4%; 95% CI, 1.4 to 4.3; P = 0.046). The overall transmission rate was 8.5% (140 infants), with an increased rate in the zidovudine-alone group (P = 0.03 for the comparisons with the two- and three-drug groups). On multivariate analysis, zidovudine monotherapy, a higher maternal viral load, and maternal use of illegal substances were significantly associated with transmission. The rate of neutropenia was significantly increased in the three-drug group (P<0.001 for both comparisons with the other groups).
Conclusions
In neonates whose mothers did not receive ART during pregnancy, prophylaxis with a two- or three-drug ART regimen is superior to zidovudine alone for the prevention of intrapartum HIV transmission; the two-drug regimen has less toxicity than the three-drug regimen. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development [NICHD] and others; ClinicalTrials.gov number, NCT00099359.)
doi:10.1056/NEJMoa1108275
PMCID: PMC3590113  PMID: 22716975
11.  Pregnancy and Infant Outcomes among HIV-Infected Women Taking Long-Term ART with and without Tenofovir in the DART Trial 
PLoS Medicine  2012;9(5):e1001217.
Diana Gibb and colleagues investigate the effect of in utero tenofovir exposure by analyzing the pregnancy and infant outcomes of HIV-infected women enrolled in the DART trial.
Background
Few data have described long-term outcomes for infants born to HIV-infected African women taking antiretroviral therapy (ART) in pregnancy. This is particularly true for World Health Organization (WHO)–recommended tenofovir-containing first-line regimens, which are increasingly used and known to cause renal and bone toxicities; concerns have been raised about potential toxicity in babies due to in utero tenofovir exposure.
Methods and Findings
Pregnancy outcome and maternal/infant ART were collected in Ugandan/Zimbabwean HIV-infected women initiating ART during The Development of AntiRetroviral Therapy in Africa (DART) trial, which compared routine laboratory monitoring (CD4; toxicity) versus clinically driven monitoring. Women were followed 15 January 2003 to 28 September 2009. Infant feeding, clinical status, and biochemistry/haematology results were collected in a separate infant study. Effect of in utero ART exposure on infant growth was analysed using random effects models.
382 pregnancies occurred in 302/1,867 (16%) women (4.4/100 woman-years [95% CI 4.0–4.9]). 226/390 (58%) outcomes were live-births, 27 (7%) stillbirths (≥22 wk), and 137 (35%) terminations/miscarriages (<22 wk). Of 226 live-births, seven (3%) infants died <2 wk from perinatal causes and there were seven (3%) congenital abnormalities, with no effect of in utero tenofovir exposure (p>0.4). Of 219 surviving infants, 182 (83%) enrolled in the follow-up study; median (interquartile range [IQR]) age at last visit was 25 (12–38) months. From mothers' ART, 62/9/111 infants had no/20%–89%/≥90% in utero tenofovir exposure; most were also zidovudine/lamivudine exposed. All 172 infants tested were HIV-negative (ten untested). Only 73/182(40%) infants were breast-fed for median 94 (IQR 75–212) days. Overall, 14 infants died at median (IQR) age 9 (3–23) months, giving 5% 12-month mortality; six of 14 were HIV-uninfected; eight untested infants died of respiratory infection (three), sepsis (two), burns (one), measles (one), unknown (one). During follow-up, no bone fractures were reported to have occurred; 12/368 creatinines and seven out of 305 phosphates were grade one (16) or two (three) in 14 children with no effect of in utero tenofovir (p>0.1). There was no evidence that in utero tenofovir affected growth after 2 years (p = 0.38). Attained height- and weight for age were similar to general (HIV-uninfected) Ugandan populations. Study limitations included relatively small size and lack of randomisation to maternal ART regimens.
Conclusions
Overall 1-year 5% infant mortality was similar to the 2%–4% post-neonatal mortality observed in this region. No increase in congenital, renal, or growth abnormalities was observed with in utero tenofovir exposure. Although some infants died untested, absence of recorded HIV infection with combination ART in pregnancy is encouraging. Detailed safety of tenofovir for pre-exposure prophylaxis will need confirmation from longer term follow-up of larger numbers of exposed children.
Trial registration
www.controlled-trials.com ISRCTN13968779
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Currently, about 34 million people (mostly in low- and middle-income countries) are infected with HIV, the virus that causes AIDS. At the beginning of the epidemic, more men than women were infected with HIV but now about half of all people living with HIV/AIDS are women, most of who became infected through unprotected sex with an infected partner. In sub-Saharan Africa alone, 12 million women are HIV-positive. Worldwide, HIV/AIDS is the leading cause of death among women of child-bearing age. Moreover, most of the 400,000 children who become infected with HIV every year acquire the virus from their mother during pregnancy or birth, or through breastfeeding, so-called mother-to-child transmission (MTCT). Combination antiretroviral therapy (ART)—treatment with cocktails of powerful antiretroviral drugs—reduces HIV-related illness and death among women, and ART given to HIV-positive mothers during pregnancy and delivery and to their newborn babies greatly reduces MTCT.
Why Was This Study Done?
Because of ongoing international efforts to increase ART coverage, more HIV-positive women in Africa have access to ART now than ever before. However, little is known about pregnancy outcomes among HIV-infected African women taking ART throughout pregnancy for their own health or about the long-term outcomes of their offspring. In particular, few studies have examined the effect of taking tenofovir (an antiretroviral drug that is now recommended as part of first-line ART) throughout pregnancy. Tenofovir readily crosses from mother to child during pregnancy and, in animal experiments, high doses of tenofovir given during pregnancy caused bone demineralization (which weakens bones), kidney problems, and impaired growth among offspring. In this study, the researchers analyze data collected on pregnancy and infant outcomes among Ugandan and Zimbabwean HIV-positive women who took ART throughout pregnancy in the Development of AntiRetroviral Therapy in Africa (DART) trial. This trial was designed to test whether ART could be safely and effectively delivered in Africa without access to the expensive laboratory tests that are routinely used to monitor ART toxicity and efficacy in developed countries.
What Did the Researchers Do and Find?
The pregnancy outcomes of 302 women who became pregnant during the DART trial and information on birth defects among their babies were collected as part of the DART protocol; information on the survival, growth, and development of the infants born to these women was collected in a separate infant study. Most of the women who became pregnant were taking tenofovir-containing ART before and throughout their pregnancies. 58% of the pregnancies resulted in a live birth, 7% resulted in a stillbirth (birth of a dead baby at any time from 22 weeks gestation to the end of pregnancy), and 35% resulted in a termination or miscarriage (before 22 weeks gestation). Of the 226 live births, seven infants died within 2 weeks and seven had birth defects. Similar proportions of the infants exposed and not exposed to tenofovir during pregnancy died soon after birth or had birth defects. Of the 182 surviving infants who were enrolled in the infant study, 14 subsequently died at an average age of 9 months, giving a 1-year mortality of 5%. None of the surviving children who were tested (172 infants) were HIV infected. No bone fractures or major kidney problems occurred during follow-up and prebirth exposure to tenofovir in utero had no effect on growth or weight gain at 2 years (in contrast to a previous US study).
What Do These Findings Mean?
By showing that prebirth tenofovir exposure does not affect pregnancy outcomes or increase birth defects, growth abnormalities, or kidney problems, these findings support the use of tenofovir-containing ART during pregnancy among HIV-positive African women, and suggest that it could also be used to prevent women of child-bearing age acquiring HIV-infection heterosexually. Notably, the observed 5% 1-year infant mortality is similar to the 2%–4% infant mortality normally seen in the region. The absence of HIV infection among the infants born to the DART participants is also encouraging. However, this is a small study (only 111 infants were exposed to tenofovir throughout pregnancy) and women were not randomly assigned to receive tenofovir-containing ART. Consequently, more studies are needed to confirm that tenofovir exposure during pregnancy does not affect pregnancy outcomes or have any long-term effects on infants. Such studies are essential because the use of tenofovir as a treatment for women who are HIV-positive is likely to increase and tenofovir may also be used in the future to prevent HIV acquisition in HIV-uninfected women.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001217.
Information is available from the US National Institute of Allergy and infectious diseases on all aspects of HIV infection and AIDS
NAM/aidsmap provides basic information about HIV/AIDS, and summaries of recent research findings on HIV care and treatment (in several languages)
Information is available from Avert, an international AIDS nonprofit on many aspects of HIV/AIDS, including detailed information on HIV/AIDS treatment and care, women, HIV and AIDS, children, HIV and AIDS, and on HIV/AIDS and pregnancy (some information in English and Spanish); personal stories of women living with HIV are available
More information about the DART trial is available
Additional patient stories about living with HIV/AIDS are available through the nonprofit website Healthtalkonline
doi:10.1371/journal.pmed.1001217
PMCID: PMC3352861  PMID: 22615543
12.  Multidisciplinary Prospective Study of Mother-to-Child Chikungunya Virus Infections on the Island of La Réunion 
PLoS Medicine  2008;5(3):e60.
Background
An outbreak of chikungunya virus affected over one-third of the population of La Réunion Island between March 2005 and December 2006. In June 2005, we identified the first case of mother-to-child chikungunya virus transmission at the Groupe Hospitalier Sud-Réunion level-3 maternity department. The goal of this prospective study was to characterize the epidemiological, clinical, biological, and radiological features and outcomes of all the cases of vertically transmitted chikungunya infections recorded at our institution during this outbreak.
Methods and Findings
Over 22 mo, 7,504 women delivered 7,629 viable neonates; 678 (9.0%) of these parturient women were infected (positive RT-PCR or IgM serology) during antepartum, and 61 (0.8%) in pre- or intrapartum. With the exception of three early fetal deaths, vertical transmission was exclusively observed in near-term deliveries (median duration of gestation: 38 wk, range 35–40 wk) in the context of intrapartum viremia (19 cases of vertical transmission out of 39 women with intrapartum viremia, prevalence rate 0.25%, vertical transmission rate 48.7%). Cesarean section had no protective effect on transmission. All infected neonates were asymptomatic at birth, and median onset of neonatal disease was 4 d (range 3–7 d). Pain, prostration, and fever were present in 100% of cases and thrombocytopenia in 89%. Severe illness was observed in ten cases (52.6%) and mainly consisted of encephalopathy (n = 9; 90%). These nine children had pathologic MRI findings (brain swelling, n = 9; cerebral hemorrhages, n = 2), and four evolved towards persistent disabilities.
Conclusions
Mother-to-child chikungunya virus transmission is frequent in the context of intrapartum maternal viremia, and often leads to severe neonatal infection. Chikungunya represents a substantial risk for neonates born to viremic parturients that should be taken into account by clinicians and public health authorities in the event of a chikungunya outbreak.
In a prospective study on the island of La Réunion, Marc Lecuit and colleagues find frequent transmission of Chikungunya virus by viremic mothers giving birth during an outbreak, resulting in serious infant illness.
Editors' Summary
Background.
Chikungunya virus, an emerging infectious agent that is transmitted by day-biting mosquitoes, was first isolated from a patient in Tanzania in the early 1950s. Since then, major outbreaks of chikungunya fever have occurred throughout sub-Saharan Africa and in Southeast Asia, India, and the Western Pacific, usually at intervals of about 7–8 years. The virus causes fever, rash, severe joint and muscle pains, and sometimes arthritis (joint inflammation). These symptoms develop within 3–7 days of being bitten by an infected mosquito. Most people recover fully within a few weeks, but joint pain can sometimes continue for years. There is no treatment for chikungunya fever, but the symptoms can be eased with anti-inflammatory drugs. Preventative measures include covering arms and legs and using insecticides to avoid insect bites and depriving the mosquitoes of their breeding sites by draining standing water from man-made containers near human dwellings.
Why Was This Study Done?
In 2005, chikungunya fever appeared for the first time on several islands in the Indian Ocean. On La Réunion Island, the disease affected 300,000 people—more than one-third of the population—between March 2005 and December 2006. In June 2005, clinicians identified the first case of mother-to-child chikungunya virus transmission (vertical transmission). Public-health officials and clinicians need to know more about how often vertical transmission occurs and its clinical implications to help them prepare for future chikungunya fever outbreaks. In this study, the researchers identify and characterize all the cases of vertical chikungunya virus transmission that occurred at the largest hospital on La Réunion Island during the 2005–6 outbreak.
What Did the Researchers Do and Find?
The researchers enrolled all 7,504 women who gave birth at the hospital during the outbreak and their 7,629 children into their study. They then used “RT-PCR” (which detects the genome of virus particles during an active infection) and “IgM serology” (which looks for an immune response to recent infection) to determine which women had been infected with chikungunya virus during their pregnancy. 678 of the new mothers had been infected sometime between conception and a week before delivery, 22 mothers had been infected between 7 and 3 days before delivery, and 39 had been infected 2 days either side of delivery (the “intrapartum” period). Except for three early fetal deaths that were associated with chikungunya virus infections, vertical transmission was seen only in babies born to mothers infected with the virus intrapartum. 19 of the babies born to these women were infected with the virus—a vertical transmission rate of nearly 50%. The women who transmitted the virus to their offspring had more virus in their placenta than those who did not transmit the infection. Delivery by emergency cesarean section did not prevent transmission. All the infected babies were born healthy but developed fever, weakness, and pain within 3–7 days. In many of them, the number of platelets (clot-forming particles) in their blood also dropped dramatically. Ten babies became seriously ill—nine of them developed brain swelling; two had bleeding into their brain. Four children had lasting disabilities at the end of the study.
What Do These Findings Mean?
These findings show that mother-to-child transmission of chikungunya virus occurs frequently when women are infected with the virus at the time of delivery and that newborn children infected by this route can become very ill. Although these results do not find that cesarean section reduces infection rates, 90% of cesarean sections involving infected infants were performed urgently, rather than planned. The study also provides no information about whether delaying delivery, provided that no fetal distress is observed, until the mother's viral load has decreased might be beneficial. More studies are needed to provide a complete description of both the short-term and long-term effects of chikungunya virus infection in newborn babies, but it is clear that clinicians should monitor babies exposed to chikungunya virus during delivery for a week after their birth. Most importantly, clinicians and public-health officials will need to take account of the threat that the chikungunya virus poses to newborn children whenever and wherever it emerges.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050060.
Read the related PLoS Medicine 10.1371/journal.pmed.0050068
The World Health Organization provides information about chikungunya fever and a brief description of the recent chikungunya outbreak in the Indian Ocean (in English, French, Spanish, Arabic, Chinese, and Russian)
The US Centers for Disease Control and Prevention has a fact sheet on chikungunya fever
The UK Health Protection Agency also provides information about chikungunya virus, including news on recent outbreaks
The French Institut de Veille Sanitaire (Institute for Public Health Surveillance) has a Web page on chikungunya (in French)
The Institut Pasteur has a Web page on chikungunya research (in French and English)
doi:10.1371/journal.pmed.0050060
PMCID: PMC2267812  PMID: 18351797
13.  Proteomic Profiling of the Amniotic Fluid to Detect Inflammation, Infection, and Neonatal Sepsis 
PLoS Medicine  2007;4(1):e18.
Background
Proteomic analysis of amniotic fluid shows the presence of biomarkers characteristic of intrauterine inflammation. We sought to validate prospectively the clinical utility of one such proteomic profile, the Mass Restricted (MR) score.
Methods and Findings
We enrolled 169 consecutive women with singleton pregnancies admitted with preterm labor or preterm premature rupture of membranes. All women had a clinically indicated amniocentesis to rule out intra-amniotic infection. A proteomic fingerprint (MR score) was generated from fresh samples of amniotic fluid using surface-enhanced laser desorption ionization (SELDI) mass spectrometry. Presence or absence of the biomarkers of the MR score was interpreted in relationship to the amniocentesis-to-delivery interval, placental inflammation, and early-onset neonatal sepsis for all neonates admitted to the Newborn Special Care Unit (n = 104). Women with “severe” amniotic fluid inflammation (MR score of 3 or 4) had shorter amniocentesis-to-delivery intervals than women with “no” (MR score of 0) inflammation or even “minimal” (MR score of 1 or 2) inflammation (median [range] MR 3–4: 0.4 d [0.0–49.6 d] versus MR 1–2: 3.8 d [0.0–151.2 d] versus MR 0: 17.0 d [0.1–94.3 d], p < 0.001). Nonetheless, a “minimal” degree of inflammation was also associated with preterm birth regardless of membrane status. There was a significant association between the MR score and severity of histological chorioamnionitis (r = 0.599, p < 0.001). Furthermore, neonatal hematological indices and early-onset sepsis significantly correlated with the MR score even after adjusting for gestational age at birth (OR for MR 3–4: 3.3 [95% CI, 1.1 to 9.2], p = 0.03). When compared with other laboratory tests routinely used to diagnose amniotic fluid inflammation and infection, the MR score had the highest accuracy to detect inflammation (white blood cell count > 100 cells/mm3), whereas the combination of Gram stain and MR score was best for rapid prediction of intra-amniotic infection (positive amniotic fluid culture).
Conclusions
High MR scores are associated with preterm delivery, histological chorioamnionitis, and early-onset neonatal sepsis. In this study, proteomic analysis of amniotic fluid was shown to be the most accurate test for diagnosis of intra-amniotic inflammation, whereas addition of the MR score to the Gram stain provides the best combination of tests to rapidly predict infection.
Proteomic analysis of amniotic fluid in addition to a Gram stain provides the best combination of tests to rapidly predict intrauterine infection.
Editors' Summary
Background.
A preterm delivery, or premature birth, is normally defined as one that occurs before 37 weeks after the last menstrual cycle (an average pregnancy lasts around 40 weeks). Premature birth is fairly common, with around 12% of births in the US fitting this definition. However, it has serious consequences, being responsible for around 70% of infant deaths and other adverse outcomes for the baby. It is not clear in all cases what directly causes premature birth or how to identify cases in which mother and child are at greater risk of serious outcomes. Evidence from case-control and other studies strongly suggests that infections of the uterus, placenta, or genital tract are associated with, and are likely to directly cause, premature deliveries. Such infections, even if they are “subclinical” (that is, they do not directly cause signs or symptoms that the doctor or patient would notice) cause inflammation in the affected tissues. Hence, it's possible that particular proteins or other molecules could provide a “signature” that would allow the inflammation to be picked up at an early stage.
Why Was This Study Done?
If inflammation could be picked up early, this might help identify mothers at risk of having a preterm delivery, and even to pinpoint cases of very severe inflammation where the baby is more at risk of poor outcomes. The researchers involved in this study had already done previous work looking at protein profiles in the amniotic fluid (the liquid directly surrounding the developing fetus). They identified a set of four protein “markers” that were closely associated with inflammation in the amniotic fluid, and developed a score based on those proteins, which they termed the “Mass Restricted” (MR) score. The researchers showed that this score could accurately identify women at risk of preterm delivery. However, before using the protein marker score in clinical practice it is very important to really be sure it is a reliable diagnostic test for preterm birth and adverse outcomes resulting from preterm birth. Therefore the researchers wanted to find out whether MR scores were associated with the outcome of pregnancy; the presence of infection in the placenta, as detected through microscopic analysis of tissue; and sepsis (severe infection) in the newborn baby.
What Did the Researchers Do and Find?
The study was based on findings from pregnant women presenting at the Yale-New Haven Hospital with symptoms of premature labor, who were all followed up to the point of delivery of the baby. In all cases the decisions about how to manage the pregnancy (for example, whether to deliver the baby or attempt to delay birth) were made by the woman and her physician, not by any procedures laid out in the research study. A total of 169 women were recruited into the study and had a sample of amniotic fluid taken as part of their routine clinical management. The researchers then analyzed this fluid to calculate the protein MR score, to look for evidence of bacterial infection, and also carried out standard laboratory tests. After childbirth the placenta was examined under the microscope to look for any evidence of inflammation. Finally, all babies were checked for any evidence of sepsis. The researchers found that, in line with findings from their previous studies, women with a higher MR score gave birth sooner. There also seemed to be a close agreement between the MR score and evidence of inflammation in the placenta, once it was analyzed under the microscope after birth. Furthermore, mothers with a high MR score were more likely to give birth to babies with suspected or confirmed sepsis. The researchers then compared the usefulness of the MR score against other potential tests for inflammation. Of all the tests compared, the MR score seemed to be the most accurate in predicting inflammation.
What Do These Findings Mean?
This study showed that the MR score was closely associated with a number of different indicators of poor outcome in preterm birth. These outcomes included sooner deliveries, sepsis in the baby, and inflammation in the placenta. In future, the MR score may provide a useful test for recognizing women at risk of preterm delivery and babies at risk of poor outcome. However, further evaluation of the test will still need to be done before it could become a standard procedure in the clinic.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040018.
Information from the US National Institutes of Health on premature babies
The March of Dimes is a US charity that funds research into prematurity
Information from Wikipedia about proteomics the area of research used to develop the protein score examined here (note: Wikipedia is an online encyclopedia that anyone can edit)
doi:10.1371/journal.pmed.0040018
PMCID: PMC1769412  PMID: 17227133
14.  Neonatal infections: group B streptococcus 
BMJ Clinical Evidence  2008;2008:0323.
Introduction
One in three women carry group B streptococci vaginally, which can infect the amniotic fluid even if the membranes are intact, or can infect the baby during delivery, causing sepsis, pneumonia, or meningitis. Very-low-birthweight infants are at much higher risk of infection or mortality, with up to 3% infected, and mortality rates of up to 30% even with immediate antibiotic treatment. Late-onset group B streptococcal infection begins after 7-9 days, and usually causes fever or meningitis, but is less often fatal compared with early infection.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of prophylactic treatment of asymptomatic neonates less than 7 days old with known risk factors for group B streptococcal infection? We searched: Medline, Embase, The Cochrane Library and other important databases up to March 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found twelve systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: different antibiotics, monitoring and selective treatment, and routine antibiotic prophylaxis.
Key Points
Early-onset neonatal sepsis, typically caused by group B streptococcal infection, usually begins within 24 hours of birth, affects up to 8 infants per 1000 live births, and leads to death if untreated. One in three women carry group B streptococci vaginally, which can infect the amniotic fluid even if the membranes are intact, or infect the baby during delivery, causing sepsis, pneumonia, or meningitis.Very low-birthweight infants are at much higher risk of infection or mortality, with up to 3% infected, and mortality rates of up to 30%, even with immediate antibiotic treatment.Late-onset group B streptococcal infection begins after 7-9 days and usually causes fever or meningitis, but is less often fatal compared with early infection.We don't know which antibiotic regimen is most effective at preventing group B streptococcal infection in high-risk neonates. Routine antibiotic prophylaxis given to low-birthweight babies after birth does not seem to be beneficial in reducing neonatal infection or mortality compared with monitoring and selective antibiotics.Increasing peripartum antibiotic prophylaxis is associated with a shift in pathogens causing neonatal sepsis, with Escherichia coli becoming a more prevalent cause.
PMCID: PMC2907963  PMID: 19450341
15.  Maternal Overweight and Obesity and Risks of Severe Birth-Asphyxia-Related Complications in Term Infants: A Population-Based Cohort Study in Sweden 
PLoS Medicine  2014;11(5):e1001648.
Martina Persson and colleagues use a Swedish national database to investigate the association between maternal body mass index in early pregnancy and severe asphyxia-related outcomes in infants delivered at term.
Please see later in the article for the Editors' Summary
Background
Maternal overweight and obesity increase risks of pregnancy and delivery complications and neonatal mortality, but the mechanisms are unclear. The objective of the study was to investigate associations between maternal body mass index (BMI) in early pregnancy and severe asphyxia-related outcomes in infants delivered at term (≥37 weeks).
Methods and Findings
A nation-wide Swedish cohort study based on data from the Medical Birth Register included all live singleton term births in Sweden between 1992 and 2010. Logistic regression analyses were used to obtain odds ratios (ORs) with 95% CIs for Apgar scores between 0 and 3 at 5 and 10 minutes, meconium aspiration syndrome, and neonatal seizures, adjusted for maternal height, maternal age, parity, mother's smoking habits, education, country of birth, and year of infant birth. Among 1,764,403 term births, 86% had data on early pregnancy BMI and Apgar scores. There were 1,380 infants who had Apgar score 0–3 at 5 minutes (absolute risk  = 0.8 per 1,000) and 894 had Apgar score 0–3 at 10 minutes (absolute risk  = 0.5 per 1,000). Compared with infants of mothers with normal BMI (18.5–24.9), the adjusted ORs (95% CI) for Apgar scores 0–3 at 10 minutes were as follows: BMI 25–29.9: 1.32 (1.10–1.58); BMI 30–34.9: 1.57 (1.20–2.07); BMI 35–39.9: 1.80 (1.15–2.82); and BMI ≥40: 3.41 (1.91–6.09). The ORs for Apgar scores 0–3 at 5 minutes, meconium aspiration, and neonatal seizures increased similarly with maternal BMI. A study limitation was lack of data on effects of obstetric interventions and neonatal resuscitation efforts.
Conclusion
Risks of severe asphyxia-related outcomes in term infants increase with maternal overweight and obesity. Given the high prevalence of the exposure and the severity of the outcomes studied, the results are of potential public health relevance and should be confirmed in other populations. Prevention of overweight and obesity in women of reproductive age is important to improve perinatal health.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Economic, technologic, and lifestyle changes over the past 30 years have created an abundance of cheap, accessible, high-calorie food. Combined with fewer demands for physical activity, this situation has lead to increasing body mass throughout most of the world. Consequently, being overweight or obese is much more common in many high-income and low-and middle-income countries compared to 1980. Worldwide estimates put the percentage of overweight or obese adults as increasing by over 10%, between 1980 and 2008.
As being overweight becomes a global epidemic, its prevalence in women of reproductive age has also increased. Pregnant women who are overweight or obese are a cause for concern because of the possible associated health risks to both the infant and mother. Research is necessary to more clearly define these risks.
Why Was This Study Done?
In this study, the researchers investigated the complications associated with excess maternal weight that could hinder an infant from obtaining enough oxygen during delivery (neonatal asphyxia). All fetuses experience a loss of oxygen during contractions, however, a prolonged loss of oxygen can impact an infant's long-term development. To explore this risk, the researchers relied on a universal scoring system known as the Apgar score. An Apgar score is routinely recorded at one, five, and ten minutes after birth and is calculated from an assessment of heart rate, respiratory effort, and color, along with reflexes and muscle tone. An oxygen deficit during delivery will have an impact on the score. A normal score is in the range of 7–10. Body mass index (BMI) a calculation that uses height and weight, was used to assess the weight status (i.e., normal, overweight, obese) of the mother during pregnancy.
What Did the Researchers Do and Find?
Using the Swedish medical birth registry (a database including nearly all the births occurring in Sweden since 1973) the researchers selected records for single births that took place between 1992 to 2010. The registry also incorporates prenatal care data and researchers further selected for records that included weight and height measurement taken during the first prenatal visit. BMI was calculated using the weight and height measurement. Based on BMI ranges that define weight groups as normal, overweight, and obesity grades I, II, and III, the researchers analyzed and compared the number of low Apgar scoring infants (Apgar 0–3) in each group. Mothers with normal weight gave birth to the majority of infants with Apgar 0–3. In comparison the proportion of low Apgar scores were greater in babies of overweight and obese mothers. The researchers found that the rates of low Apgar scores increased with maternal BMI: the authors found that rates of low Apgar score at 5 minutes increased from 0.4 per 1,000 among infants of underweight women (BMI <18.5) to 2.4 per 1,000 among infants of women with obesity class III (BMI ≥40). Furthermore, overweight (BMI 25.0–29.9) was associated with a 55% increased risk of low Apgar scores at 5 minutes; obesity grade I (BMI 30–34.9) and grade II (BMI 35.0–39.9) with an almost 2-fold and a more than 2-fold increased risk, respectively; and obesity grade ΙΙΙ (BMI ≥40.0) with a more than 3-fold increase in risk. Finally, maternal overweight and obesity also increase the risks for seizures and meconium aspiration in the neonate.
What Do These Findings Mean?
These findings suggest that the risk of experiencing an oxygen deficit increases for the babies of women who are overweight or obese. Given the high prevalence of overweight and obesity in many countries worldwide, these findings are important and suggest that preventing women of reproductive age from becoming overweight or obese is therefore important to the health of their children.
A limitation of this study is the lack of data on the effects of clinical interventions and neonatal resuscitation efforts that may have been performed at the time of birth. Also Apgar scoring is based on five variables and a low score is not the most direct way to determine if the infant has experienced an oxygen deficit. However, these findings suggest that early detection of perinatal asphyxia is particularly relevant among infants of overweight and obese women although more studies are necessary to confirm the results in other populations.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001648.
The US National Institutes of Health explains and calculates body mass index
The NIH also defines the Apgar scoring system
The United Kingdom's National Health Service has information for pregnant woman who are overweight
The UK-based Overseas Development Institute discusses how changes in diet have led to a worldwide health crisis in its “Future Diets” publication
Information about the Swedish health care system is available
Information in English is available from the National Board of Health and Welfare in Sweden
doi:10.1371/journal.pmed.1001648
PMCID: PMC4028185  PMID: 24845218
16.  US Birth Weight/Gestational Age-Specific Neonatal Mortality: 1995–1997 Rates for Whites, Hispanics, and Blacks 
Pediatrics  2003;111(1):e61-e66.
Objective
In recent years, gains in neonatal survival have been most evident among very low birth weight, preterm, and low birth weight (LBW) infants. Most of the improvement in neonatal survival since the early 1980s seems to be the consequence of decreasing birth weight-specific mortality rates, which occurred during a period of increasing preterm and LBW rates. Although the decline in neonatal mortality has been widely publicized in the United States, research suggests that clinicians may still underestimate the chances of survival of an infant who is born too early or too small and may overestimate the eventuality of serious disability. So that clinicians may have current and needed ethnic- and race-specific estimates of the “chances” of early survival for newborn infants, we examined birth weight/gestational age-specific neonatal mortality rates for the 3 largest ethnic/racial groups in the United States: non-Hispanic whites, Hispanics, and non-Hispanic blacks. Marked racial variation in birth weight and gestational age-specific mortality has long been recognized, and growing concerns have been raised about ongoing and increasing racial disparities in pregnancy outcomes. Our purpose for this investigation was to provide an up-to-date national reference for birth weight/gestational age-specific neonatal mortality rates for use by clinicians in care decision making and discussions with parents.
Methods
The National Center for Health Statistics linked live birth-infant death cohort files for 1995–1997 were used for this study. Singleton live births to US resident mothers with a reported maternal ethnicity/race of non-Hispanic white, non-Hispanic black, or Hispanic (n = 10 610 715) were selected for analysis. Birth weight/gestational age-specific neonatal mortality rates were calculated using 250 g/2-week intervals for each ethnic/racial group.
Results
The overall neonatal mortality rates for whites, Hispanics, and blacks were 3.24, 3.45, and 8.16 neonatal deaths per 1000 live births, and the proportion of births <28 weeks was 0.35%, 0.45%, and 1.39%, respectively. Newborns who weighed <1500 g comprised <2.5% of all births in each racial/ethnic group but accounted for >50% of neonatal deaths. For whites, Hispanics, and blacks, >50% of newborns 24 to 25 weeks of gestational age survived. For most combinations of birth weights <3500 g and gestational ages of <37 weeks, the neonatal mortality rate was lowest among blacks, compared with whites or Hispanics. At these same gestational age/birth weight combinations, Hispanics have slightly lower mortality rates than whites. For combinations of birth weights >3500 g and gestational ages of 37 to 41 weeks, Hispanics had the lowest neonatal mortality rate. In these birth weight/gestational age combinations, where approximately two thirds of births occur, blacks had the highest neonatal mortality rate.
Conclusions
Compared with earlier reports, these data suggest that a substantial improvement in birth weight/gestational age-specific neonatal mortality has occurred in the United States. Regardless of ethnicity/race, the risk of a neonatal death does not exceed 50% (the suggested definition for the limit of viability), except for birth weights below 500 g and gestational ages <24 weeks. Notwithstanding, ethnic/racial variations in neonatal mortality rates continue to persist, both in overall rates and within birth weight/gestational age categories. Blacks continue to have higher proportions for preterm and LBW births, compared with either whites or Hispanics. At the same time, blacks experience lower risks of neonatal mortality for preterm and LBW infants, while having higher risks of mortality among term, postterm, normal birth weight, and macrosomic births.
doi:10.1542/peds.111.1.e61
PMCID: PMC1382183  PMID: 12509596
VLBW, very low birth weight; LBW, low birth weight; BG-NMR, birth weight/gestational age-specific neonatal mortality rate; NCHS, National Center for Health Statistics; LMP, last normal menstrual period
17.  Early and Late Onset Sepsis in Late Preterm Infants 
Background
Preterm birth is increasing worldwide, and late preterm births, which comprise more than 70% of all preterm births, account for much of the increase. Early and late onset sepsis results in significant mortality in extremely preterm infants, but little is known about sepsis outcomes in late preterm infants.
Methods
This is an observational cohort study of infants < 121 days of age (119,130 infants less than or equal to 3 days of life and 106,142 infants between 4 and 120 days of life) with estimated gestational age at birth between 34 and 36 weeks, admitted to 248 neonatal intensive care units in the United States between 1996 and 2007.
Results
During the study period, the cumulative incidence of early and late onset sepsis was 4.42 and 6.30 episodes per 1000 admissions, respectively. Gram-positive organisms caused the majority of early and late onset sepsis episodes. Infants with early onset sepsis caused by Gram-negative rods and infants with late onset sepsis were more likely to die than their peers with sterile blood cultures (OR 4.39, 95% CI 1.71–11.23, P=0.002; and OR 3.37, 95% CI 2.35–4.84, P<0.001, respectively).
Conclusion
Late preterm infants demonstrate specific infection rates, pathogen distribution, and mortality associated with early and late onset sepsis. The results of this study are generalizable to late preterm infants admitted to the special care nursery or neonatal intensive care unit.
PMCID: PMC2798577  PMID: 19953725
blood culture; neonate; prematurity; infection; near term
18.  Methicillin-Resistant and Susceptible Staphylococcus aureus Bacteremia and Meningitis in Preterm Infants 
Pediatrics  2012;129(4):e914-e922.
BACKGROUND:
Data are limited on the impact of methicillin-resistant Staphylococcus aureus (MRSA) on morbidity and mortality among very low birth weight (VLBW) infants with S aureus (SA) bacteremia and/or meningitis (B/M).
METHODS:
Neonatal data for VLBW infants (birth weight 401–1500 g) born January 1, 2006, to December 31, 2008, who received care at centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network were collected prospectively. Early-onset (≤72 hours after birth) and late-onset (>72 hours) infections were defined by blood or cerebrospinal fluid cultures and antibiotic treatment of ≥5 days (or death <5 days with intent to treat). Outcomes were compared for infants with MRSA versus methicillin-susceptible S aureus (MSSA) B/M.
RESULTS:
Of 8444 infants who survived >3 days, 316 (3.7%) had SA B/M. Eighty-eight had MRSA (1% of all infants, 28% of infants with SA); 228 had MSSA (2.7% of all infants, 72% of infants with SA). No infant had both MRSA and MSSA B/M. Ninety-nine percent of MRSA infections were late-onset. The percent of infants with MRSA varied by center (P < .001) with 9 of 20 centers reporting no cases. Need for mechanical ventilation, diagnosis of respiratory distress syndrome, necrotizing enterocolitis, and other morbidities did not differ between infants with MRSA and MSSA. Mortality was high with both MRSA (23 of 88, 26%) and MSSA (55 of 228, 24%).
CONCLUSIONS:
Few VLBW infants had SA B/M. The 1% with MRSA had morbidity and mortality rates similar to infants with MSSA. Practices should provide equal focus on prevention and management of both MRSA and MSSA infections among VLBW infants.
doi:10.1542/peds.2011-0966
PMCID: PMC3313632  PMID: 22412036
Staphylococcus aureus; methicillin resistant; infant; newborn
19.  Clinical Benefits, Costs, and Cost-Effectiveness of Neonatal Intensive Care in Mexico 
PLoS Medicine  2010;7(12):e1000379.
Joshua Salomon and colleagues performed a cost-effectiveness analysis using health and economic outcomes following preterm birth in Mexico and showed that neonatal intensive care provided high value for the money in this setting.
Background
Neonatal intensive care improves survival, but is associated with high costs and disability amongst survivors. Recent health reform in Mexico launched a new subsidized insurance program, necessitating informed choices on the different interventions that might be covered by the program, including neonatal intensive care. The purpose of this study was to estimate the clinical outcomes, costs, and cost-effectiveness of neonatal intensive care in Mexico.
Methods and Findings
A cost-effectiveness analysis was conducted using a decision analytic model of health and economic outcomes following preterm birth. Model parameters governing health outcomes were estimated from Mexican vital registration and hospital discharge databases, supplemented with meta-analyses and systematic reviews from the published literature. Costs were estimated on the basis of data provided by the Ministry of Health in Mexico and World Health Organization price lists, supplemented with published studies from other countries as needed. The model estimated changes in clinical outcomes, life expectancy, disability-free life expectancy, lifetime costs, disability-adjusted life years (DALYs), and incremental cost-effectiveness ratios (ICERs) for neonatal intensive care compared to no intensive care. Uncertainty around the results was characterized using one-way sensitivity analyses and a multivariate probabilistic sensitivity analysis. In the base-case analysis, neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestational age prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs, at incremental costs per infant of US$11,400, US$9,500, and US$3,000, respectively, compared to an alternative of no intensive care. The ICERs of neonatal intensive care at 24–26, 27–29, and 30–33 weeks were US$1,200, US$650, and US$240, per DALY averted, respectively. The findings were robust to variation in parameter values over wide ranges in sensitivity analyses.
Conclusions
Incremental cost-effectiveness ratios for neonatal intensive care imply very high value for money on the basis of conventional benchmarks for cost-effectiveness analysis.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks but increasing numbers of babies are being born preterm, before they reach 37 weeks of gestation (the period during which a baby develops in its mother). In developed countries and some middle-income countries such as Mexico, improvements in the care of newborn babies (neonatal intensive care) mean that more preterm babies survive now than in the past. Nevertheless, preterm birth is still a major cause of infant death worldwide that challenges attainment of Target 5 of Millennium Development Goal 4—the reduction of the global under-five mortality rate by two-thirds of the 1990 rate by 2015 (the Millennium Development Goals, which were agreed by world leaders in 2000, aim to reduce world poverty). Furthermore, many preterm babies who survive have long-term health problems and disabilities such as cerebral palsy, deafness, or learning difficulties. The severity of these disabilities and their long-term costs to families and to society depend on the baby's degree of prematurity.
Why Was This Study Done?
Mexico recently reformed its health system in an effort to improve access to care, particularly for the poorest sections of its population, and to improve the quality of its health care. The central component of this health care reform is the System of Social Protection of Health (SSPH). The SSPH contains a family health insurance program—Seguro Popular—that aims to provide the 50 million uninsured people living in Mexico with free access to an explicit set of health care interventions. As with any insurance program, decisions have to be made about which interventions Seguro Poplar should cover. Should neonatal intensive care be covered, for example? Do the benefits of this intervention (increased survival of babies) outweigh the costs of neonatal care and of long-term care for survivors with disabilities? In other words, is neonatal intensive care cost-effective? In this study, the researchers investigate this question by estimating the clinical benefits, costs, and cost-effectiveness of neonatal intensive care in Mexico.
What Did the Researchers Do and Find?
The researchers built a decision analytic model, a mathematical model that combines evidence on the outcomes and costs of alternative treatments to help inform decisions about health care policy. They gathered data about the health outcomes of preterm births in Mexico from registers of births and deaths and from hospital discharge databases, and estimated the costs of neonatal intensive care and long-term care for disabled survivors using data from the Mexican Ministry of Health and the World Health Organization. They then applied their model, which estimates changes in parameters such as life expectancy, lifetime costs, disability-adjusted life years (DALYs; one DALY represents the loss of a year of healthy life), and incremental cost-effectiveness ratios (ICERs; the additional cost expended for each DALY averted) for neonatal intensive care compared to no intensive care, to a group of 2 million infants. Neonatal intensive care for infants born at 24–26, 27–29, and 30–33 weeks gestation prolonged life expectancy by 28, 43, and 34 years and averted 9, 15, and 12 DALYs at incremental costs of US$11,000, US$10,000, and US$3000, respectively, compared to no intensive care. The ICERs of neonatal intensive care for babies born at these times were US$1200, US$700, and US$300 per DALY averted, respectively.
What Do These Findings Mean?
Interventions with ICERs of less than a country's per capita gross domestic product (GDP) are highly cost-effective; those with ICERs of 1–3 times the per capita GDP are potentially cost-effective. Mexico's per capita GDP in 2005 was approximately US$8,200. Thus, neonatal intensive care could provide exceptional value for money in Mexico (and maybe in other middle-income countries), even for very premature babies. The accuracy of these findings inevitably depends on the assumptions used to build the decision analytic model and on the accuracy of the data fed into it, but the findings were little changed by a wide range of alterations that the researchers made to the model. Importantly, however, this cost-effectiveness analysis focuses on health and economic consequences of different intervention choices, and does not capture all aspects of well-being. Decisions regarding neonatal intensive care will need to be based on a full consideration of all relevant factors, including ethical issues, and cost-effectiveness analyses should continue to be updated as new data emerge on health outcomes and costs associated with neonatal intensive care.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000379.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
MedlinePlus provides links to other information on premature babies (in English and Spanish)
The United Nations Childrens Fund (UNICEF) works for children's rights, survival, development and protection around the world; it provides information on Millennium Development Goal 4 and its Childinfo website provides detailed statistics about child survival and health (some information in several languages)
A PLoS Medicine Policy Forum by Núria Homedes and Antonio Ugalde discusses health care reforms in Mexico
doi:10.1371/journal.pmed.1000379
PMCID: PMC3001895  PMID: 21179496
20.  Global Estimates of Syphilis in Pregnancy and Associated Adverse Outcomes: Analysis of Multinational Antenatal Surveillance Data 
PLoS Medicine  2013;10(2):e1001396.
Using multinational surveillance data, Lori Newman and colleagues estimate global rates of active syphilis in pregnant women, adverse effects, and antenatal coverage and treatment needed to meet WHO goals.
Background
The World Health Organization initiative to eliminate mother-to-child transmission of syphilis aims for ≥90% of pregnant women to be tested for syphilis and ≥90% to receive treatment by 2015. We calculated global and regional estimates of syphilis in pregnancy and associated adverse outcomes for 2008, as well as antenatal care (ANC) coverage for women with syphilis.
Methods and Findings
Estimates were based upon a health service delivery model. National syphilis seropositivity data from 97 of 193 countries and ANC coverage from 147 countries were obtained from World Health Organization databases. Proportions of adverse outcomes and effectiveness of screening and treatment were from published literature. Regional estimates of ANC syphilis testing and treatment were examined through sensitivity analysis. In 2008, approximately 1.36 million (range: 1.16 to 1.56 million) pregnant women globally were estimated to have probable active syphilis; of these, 80% had attended ANC. Globally, 520,905 (best case: 425,847; worst case: 615,963) adverse outcomes were estimated to be caused by maternal syphilis, including approximately 212,327 (174,938; 249,716) stillbirths (>28 wk) or early fetal deaths (22 to 28 wk), 91,764 (76,141; 107,397) neonatal deaths, 65,267 (56,929; 73,605) preterm or low birth weight infants, and 151,547 (117,848; 185,245) infected newborns. Approximately 66% of adverse outcomes occurred in ANC attendees who were not tested or were not treated for syphilis. In 2008, based on the middle case scenario, clinical services likely averted 26% of all adverse outcomes. Limitations include missing syphilis seropositivity data for many countries in Europe, the Mediterranean, and North America, and use of estimates for the proportion of syphilis that was “probable active,” and for testing and treatment coverage.
Conclusions
Syphilis continues to affect large numbers of pregnant women, causing substantial perinatal morbidity and mortality that could be prevented by early testing and treatment. In this analysis, most adverse outcomes occurred among women who attended ANC but were not tested or treated for syphilis, highlighting the need to improve the quality of ANC as well as ANC coverage. In addition, improved ANC data on syphilis testing coverage, positivity, and treatment are needed.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Syphilis—a sexually transmitted bacterial infection caused by Treponema pallidum—can pass from a mother who is infected to her unborn child. Screening pregnant women for syphilis during routine antenatal care by looking for a reaction to T. pallidum in the blood (seropositivity) and then treating any detected infections with penicillin injections has been feasible for many years, even in low-resource settings. However, because coverage of testing and treatment of syphilis remains low in many countries, mother-to-child transmission of syphilis—“congenital syphilis”—is still a global public health problem. In 2007, the World Health Organization (WHO) estimated that there were 2 million syphilis infections among pregnant women annually, 65% of which resulted in adverse pregnancy outcomes: the baby's death during early or late pregnancy (fetal death and stillbirth, respectively) or soon after birth (neonatal death), or the birth of an infected baby. Babies born with syphilis often have a low birth weight and develop problems such as blindness, deafness, and seizures if not treated.
Why Was This Study Done?
In 2007, WHO launched an initiative to eliminate congenital syphilis that set targets of at least 90% of pregnant women being tested for syphilis and at least 90% of seropositive pregnant women receiving adequate treatment by 2015. To assess the initiative's progress and to guide policy and advocacy efforts, accurate global data on the burden of syphilis in pregnancy and on associated adverse outcomes are needed. Unfortunately, even in developed countries with good laboratory facilities, definitive diagnosis of congenital syphilis is difficult. Estimates of the global burden can be obtained, however, using mathematical models. In this study, the researchers generate global and regional estimates of the burden of syphilis in pregnancy and associated adverse outcomes for 2008 using a health services delivery model.
What Did the Researchers Do and Find?
The researchers developed a mathematical model to estimate the number of syphilis-infected pregnant women in each country and in each region, and to estimate the regional and global numbers of adverse pregnancy outcomes associated with syphilis. They used national syphilis seropositivity data and information on antenatal care coverage from WHO and estimates of the effectiveness of screening and treatment from published literature. Using these data and their model, the researchers estimated that, in 2008, 1.4 million pregnant women, 80% of whom had attended antenatal care services, had an active syphilis infection. Assuming a scenario in which the percentage of pregnant women tested for syphilis and adequately treated ranged from 30% for Africa and the Mediterranean region to 70% for Europe (a scenario defined in consultation with WHO advisors), the researchers estimated that maternal syphilis caused 520,000 adverse outcomes in 2008, including 215,000 stillbirths or fetal deaths, 90,000 neonatal deaths, 65,000 preterm or low birth weight infants, and 150,000 infants with congenital disease. About 66% of these adverse effects occurred in women who had attended antenatal care but were either not tested or not treated for syphilis. Finally, the researchers estimated that in 2008, clinical services averted 26% of all adverse outcomes.
What Do These Findings Mean?
These findings, which update and extend previous estimates of the global burden of congenital syphilis, indicate that syphilis continues to affect a large number of pregnant women and their offspring. The current findings, which cannot be directly compared to previous estimates because of the different methodologies used, are likely to be affected by the accuracy of the data fed into the researchers' model. In particular, the data on the percentage of the population infected with syphilis in individual countries used in this study came from the HIV Universal Access reporting system and may not be nationally representative. Nevertheless, these findings suggest that syphilis continues to be an important cause of adverse outcomes of pregnancy, partly because pregnant women often do not receive syphilis screening and prompt treatment during routine antenatal care. The researchers recommend, therefore, that all countries should ensure that all pregnant women receive an essential package of high-quality antenatal care services that includes routine and easy access to syphilis testing and treatment. Congenital syphilis, they conclude, can only be eliminated if decision-makers at all levels prioritize the provision, quality, and monitoring of this basic antenatal care service, which has the potential to reduce infant mortality and improve maternal health.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001396.
The World Health Organization provides information on sexually transmitted diseases, including details of its strategy for the global elimination of congenital syphilis, the investment case for the elimination of mother-to-child transmission of syphilis, and regional updates on progress towards elimination (some information is available in several languages)
The Pan American Health Organization provides information on efforts to eliminate congenital syphilis in Latin America (in English and Spanish), and the Asia-Pacific Prevention of Parent-to-Child Transmission Task Force provides information on efforts to eliminate congenital syphilis in Asia Pacific
The US Centers for Disease Control and Prevention has a fact sheet on syphilis (in English and Spanish)
The UK National Health Service Choices website also has a page on syphilis
MedlinePlus provides information on congenital syphilis and links to additional syphilis resources (in English and Spanish)
The London School of Hygiene and Tropical Medicine provides a toolkit for the introduction of rapid syphilis tests
Haiti: Congenital Syphilis on the Way Out is a YouTube video describing the introduction of rapid diagnostic tests for syphilis in remote parts of Haiti
doi:10.1371/journal.pmed.1001396
PMCID: PMC3582608  PMID: 23468598
21.  Induction of Labor versus Expectant Management in Women with Preterm Prelabor Rupture of Membranes between 34 and 37 Weeks: A Randomized Controlled Trial 
PLoS Medicine  2012;9(4):e1001208.
In a randomized controlled trial David van der Ham and colleagues investigate induction of labor versus expectant management for women with preterm prelabor rupture of membranes.
Background
At present, there is insufficient evidence to guide appropriate management of women with preterm prelabor rupture of membranes (PPROM) near term.
Methods and Findings
We conducted an open-label randomized controlled trial in 60 hospitals in The Netherlands, which included non-laboring women with >24 h of PPROM between 34+0 and 37+0 wk of gestation. Participants were randomly allocated in a 1∶1 ratio to induction of labor (IoL) or expectant management (EM) using block randomization. The main outcome was neonatal sepsis. Secondary outcomes included mode of delivery, respiratory distress syndrome (RDS), and chorioamnionitis. Patients and caregivers were not blinded to randomization status. We updated a prior meta-analysis on the effect of both interventions on neonatal sepsis, RDS, and cesarean section rate.
From 1 January 2007 to 9 September 2009, 776 patients in 60 hospitals were eligible for the study, of which 536 patients were randomized. Four patients were excluded after randomization. We allocated 266 women (268 neonates) to IoL and 266 women (270 neonates) to EM. Neonatal sepsis occurred in seven (2.6%) newborns of women in the IoL group and in 11 (4.1%) neonates in the EM group (relative risk [RR] 0.64; 95% confidence interval [CI] 0.25 to 1.6). RDS was seen in 21 (7.8%, IoL) versus 17 neonates (6.3%, EM) (RR 1.3; 95% CI 0.67 to 2.3), and a cesarean section was performed in 36 (13%, IoL) versus 37 (14%, EM) women (RR 0.98; 95% CI 0.64 to 1.50). The risk for chorioamnionitis was reduced in the IoL group. No serious adverse events were reported.
Updating an existing meta-analysis with our trial results (the only eligible trial for the update) indicated RRs of 1.06 (95% CI 0.64 to 1.76) for neonatal sepsis (eight trials, 1,230 neonates) and 1.27 (95% CI 0.98 to 1.65) for cesarean section (eight trials, 1,222 women) for IoL compared with EM.
Conclusions
In women whose pregnancy is complicated by late PPROM, neither our trial nor the updated meta-analysis indicates that IoL substantially improves pregnancy outcomes compared with EM.
Trial registration
Current Controlled Trials ISRCTN29313500
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last around 40 weeks, but in industrialized countries, 5%–10% of babies are born before 37 weeks of gestation (gestation is the period during which a baby develops in its mother's womb). Premature birth is a major cause of infant death in many developed countries, and preterm babies can also have short- and/or long-term health problems such as breathing problems, increased susceptibility to life-threatening infections, and learning and developmental disabilities. There are many reasons why some babies are born prematurely, but preterm prelabor rupture of the membranes (PPROM) accounts for 30%–40% of preterm deliveries. Inside the womb, the baby is held in a fluid-filled bag called the amniotic sac. The amniotic fluid cushions the baby, helps some of its organs develop, and protects both mother and baby from infection. The membranes that form the sac usually break at the start of labor (“water breaking”), but in PPROM, the membranes break before the baby is fully grown. PPROM increases the mother's risk of a womb infection called chorioamnionitis and the baby's risk of neonatal sepsis (blood infection), and can trigger early labor.
Why Was This Study Done?
There is currently no consensus on how to manage women whose membranes rupture between 34 and 37 weeks' gestation. Some guidelines recommend immediate induction of labor if PPROM occurs at or beyond 34 weeks' gestation. Others recommend that labor not be induced unless the mother develops signs of infection such as a high temperature or has not delivered her baby spontaneously by 37 weeks' gestation (expectant management). Before 34 weeks' gestation, expectant management is generally recommended. In this randomized controlled trial, the researchers compare the effects of induction of labor and of expectant management on the rate of neonatal sepsis (the proportion of babies that develop neonatal sepsis; the trial's primary outcome) and on secondary outcomes such as the rates of neonatal respiratory distress syndrome (RDS), cesarean section (surgical delivery), and chorioamnionitis in women with PPROM between 34 and 37 weeks' gestation. The researchers also undertake a meta-analysis of published trials on the effect of both interventions on pregnancy outcomes. A randomized controlled trial compares the effects of different interventions in groups of individuals chosen through the play of chance; meta-analysis is a statistical approach that combines the results of several trials.
What Did the Researchers Do and Find?
In the PPROM Expectant Management versus Induction of Labor (PRROMEXIL) trial, 532 non-laboring women with PPROM between 34 and 37 weeks' gestation were randomly assigned to either immediate induction of labor or expectant management. Neonatal sepsis occurred in seven babies born to women in the induction of labor group and in 11 babies born to women in the expectant management group. This difference was not statistically significant. That is, it could have happened by chance. Similarly, although more babies born to women in the induction of labor group than in the expectant management group developed RDS (21 and 17 babies, respectively), this difference was not significant. Cesarean section rates were similar in both intervention groups, but the risk of chorioamnionitis was slightly reduced in the induction of labor group compared to the expectant management group. Finally, the researchers' meta-analysis (which included these new results) found no significant differences in the risk of neonatal sepsis, RDS, or cesarean section associated with the two interventions.
What Do These Findings Mean?
These findings show that, compared to expectant management, induction of labor did not reduce the incidence of neonatal sepsis in pregnancies complicated by PPROM between 34 and 37 weeks' gestation. However, because fewer babies than expected born to the women in the expectant management group developed neonatal sepsis, this trial was underpowered. That is, too few women were enrolled in the trial to enable the detection of a small difference between the interventions in the neonatal sepsis rate. These findings also show that induction of labor did not substantially affect most of the secondary outcomes measured by the researchers. Given these results and those of their meta-analysis, the researchers conclude that, in women whose pregnancy is complicated by PPROM late in pregnancy, induction of labor does not substantially improve the outcome for either the woman or her baby compared to expectant management.
Additional Information
Please access these web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001208.
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish); its News Moms Need blog contains a post on PPROM
Tommy's is a nonprofit organization that funds research and provides information on the causes and prevention of miscarriage, premature birth, and stillbirth
The Royal College of Obstetricians and Gynaecologists guidelines on the diagnosis, investigation, and management of PPROM are available (in English and Russian)
Information about the PPROMEXIL trial is available
Personal stories about PPROM are available on the Austprem web site, a non-profit organization that provides information about prematurity and support for parents of premature babies in Australia
MedlinePlus provides links to other information on premature babies (in English and Spanish)
doi:10.1371/journal.pmed.1001208
PMCID: PMC3335867  PMID: 22545024
22.  Effect of Resident Physician Education Regarding Selective Chemoprophylaxis for the Prevention of Early Onset Group B Streptococcal Sepsis: An Outcome Study 
Objective: The aim of this study was to evaluate the effect of a voluntary protocol for selective intrapartum chemoprophylaxis on the incidence of early onset group B streptococcal sepsis (GBS EOS).
Methods: Cases of GBS EOS were defined as a positive GBS culture from a normally sterile fluid obtained during the first 7 days of life. All cases of GBS EOS at an urban, university-affiliated community hospital were reviewed during 2 time periods. The 2-year period before instituting a resident education program to promote selective chemoprophylaxis (1988–89) was retrospectively reviewed; the 2-year period after the education program was introduced (1990–91) was prospectively recorded. The outcome measure was the incidence of GBS EOS.
Results: The rate of GBS EOS was 7/14,335 deliveries (0.05%) before and 9/13,999 (0.064%) after the introduction of the education program (observed difference between proportions 0.016%, 95% confidence interval [CI] for the difference between the proportions –0.071% to 0.04%, P = not significant [NS]). The rate of GBS EOS in preterm infants was 5/1,331 (0.376%) before and 3/1,297 (0.23%) afterward (observed difference between proportions 0.14%, 95% CI –0.28% to 0.56%, P = NS). The incidence of GBS EOS did not decrease during the latter period due to failure of antepartum cultures to predict intrapartum GBS colonization (2 cases); non-compliance with voluntary recommendations to administer chemoprophylaxis (2 cases); failure of chemoprophylaxis or therapy for intraamniotic infection to prevent neonatal infection (3 cases); and occurrence of GBS EOS in infants without risk factors (2 cases).
Conclusions: An education program for resident physicians regarding chemoprophylaxis for GBS EOS did not significantly reduce the absolute incidence of disease. Alternative strategies are needed that redress the causes of failure inherent in the current guidelines. Some cases of GBS EOS are not preventable because the parturient does not have risk factors that indicate chemoprophylaxis.
doi:10.1155/S1064744994000116
PMCID: PMC2366147  PMID: 18472876
23.  Neonatal sepsis 
Virulence  2013;5(1):170-178.
Neonatal sepsis continues to be a common and significant health care burden, especially in very-low-birth-weight infants (VLBW <1500 g). Though intrapartum antibiotic prophylaxis has decreased the incidence of early-onset group B streptococcal infection dramatically, it still remains a major cause of neonatal sepsis. Moreover, some studies among VLBW preterm infants have shown an increase in early-onset sepsis caused by Escherichia coli. As the signs and symptoms of neonatal sepsis are nonspecific, early diagnosis and prompt treatment remains a challenge. There have been a myriad of studies on various diagnostic markers like hematological indices, acute phase reactants, C-reactive protein, procalcitonin, cytokines, and cell surface markers among others. Nonetheless, further research is needed to identify a biomarker with high diagnostic accuracy and validity. Some of the newer markers like inter α inhibitor proteins have shown promising results thereby potentially aiding in early detection of neonates with sepsis. In order to decrease the widespread, prolonged use of unnecessary antibiotics and improve the outcome of the infants with sepsis, reliable identification of sepsis at an earlier stage is paramount.
doi:10.4161/viru.26906
PMCID: PMC3916371  PMID: 24185532
neonatal sepsis; epidemiology; microbiology; biomarkers; algorithms; newer tests; screening; group B streptococcus; antibiotic prophylaxis
24.  Approach to Infants Born at 22 to 24 Weeks’ Gestation: Relationship to Outcomes of More-Mature Infants 
Pediatrics  2012;129(6):e1508-e1516.
OBJECTIVE:
We sought to determine if a center’s approach to care of premature infants at the youngest gestational ages (22–24 weeks’ gestation) is associated with clinical outcomes among infants of older gestational ages (25–27 weeks’ gestation).
METHODS:
Inborn infants of 401 to 1000 g birth weight and 22 0/7 to 27 6/7 weeks’ gestation at birth from 2002 to 2008 were enrolled into a prospectively collected database at 20 centers participating in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Markers of an aggressive approach to care for 22- to 24-week infants included use of antenatal corticosteroids, cesarean delivery, and resuscitation. The primary outcome was death before postnatal day 120 for infants of 25 to 27 weeks’ gestation. Secondary outcomes were the combined outcomes of death or a number of morbidities associated with prematurity.
RESULTS:
Our study included 3631 infants 22 to 24 weeks’ gestation and 5227 infants 25 to 27 weeks’ gestation. Among the 22- to 24-week infants, use of antenatal corticosteroids ranged from 28% to 100%, cesarean delivery from 13% to 65%, and resuscitation from 30% to 100% by center. Centers with higher rates of antenatal corticosteroid use in 22- to 24-week infants had reduced rates of death, death or retinopathy of prematurity, death or late-onset sepsis, death or necrotizing enterocolitis, and death or neurodevelopmental impairment in 25- to 27-week infants.
CONCLUSIONS:
This study suggests that physicians’ willingness to provide care to extremely low gestation infants as measured by frequency of use of antenatal corticosteroids is associated with improved outcomes for more-mature infants.
doi:10.1542/peds.2011-2216
PMCID: PMC3362905  PMID: 22641761
low-birth weight infant; NICUs; treatment; patient outcome assessment
25.  Neonatal Mortality Levels for 193 Countries in 2009 with Trends since 1990: A Systematic Analysis of Progress, Projections, and Priorities 
PLoS Medicine  2011;8(8):e1001080.
Mikkel Oestergaard and colleagues develop annual estimates for neonatal mortality rates and neonatal deaths for 193 countries for 1990 to 2009, and forecasts into the future.
Background
Historically, the main focus of studies of childhood mortality has been the infant and under-five mortality rates. Neonatal mortality (deaths <28 days of age) has received limited attention, although such deaths account for about 41% of all child deaths. To better assess progress, we developed annual estimates for neonatal mortality rates (NMRs) and neonatal deaths for 193 countries for the period 1990–2009 with forecasts into the future.
Methods and Findings
We compiled a database of mortality in neonates and children (<5 years) comprising 3,551 country-years of information. Reliable civil registration data from 1990 to 2009 were available for 38 countries. A statistical model was developed to estimate NMRs for the remaining 155 countries, 17 of which had no national data. Country consultation was undertaken to identify data inputs and review estimates. In 2009, an estimated 3.3 million babies died in the first month of life—compared with 4.6 million neonatal deaths in 1990—and more than half of all neonatal deaths occurred in five countries of the world (44% of global livebirths): India 27.8% (19.6% of global livebirths), Nigeria 7.2% (4.5%), Pakistan 6.9% (4.0%), China 6.4% (13.4%), and Democratic Republic of the Congo 4.6% (2.1%). Between 1990 and 2009, the global NMR declined by 28% from 33.2 deaths per 1,000 livebirths to 23.9. The proportion of child deaths that are in the neonatal period increased in all regions of the world, and globally is now 41%. While NMRs were halved in some regions of the world, Africa's NMR only dropped 17.6% (43.6 to 35.9).
Conclusions
Neonatal mortality has declined in all world regions. Progress has been slowest in the regions with high NMRs. Global health programs need to address neonatal deaths more effectively if Millennium Development Goal 4 (two-thirds reduction in child mortality) is to be achieved.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Every year, more than 8 million children die before their fifth birthday. Most of these deaths occur in developing countries and most are caused by preventable or treatable diseases. In 2000, world leaders set a target of reducing child mortality to one-third of its 1990 level by 2015 as Millennium Development Goal 4 (MDG4). This goal, together with seven others, is designed to help improve the social, economic, and health conditions in the world's poorest countries. In recent years, progress towards reducing child mortality has accelerated but remains insufficient to achieve MDG4. In particular, progress towards reducing neonatal deaths—deaths during the first 28 days of life—has been slow and neonatal deaths now account for a greater proportion of global child deaths than in 1990. Currently, nearly 41% of all deaths among children under the age of 5 years occur during the neonatal period. The major causes of neonatal deaths are complications of preterm delivery, breathing problems during or after delivery (birth asphyxia), and infections of the blood (sepsis) and lungs (pneumonia). Simple interventions such as improved hygiene at birth and advice on breastfeeding can substantially reduce neonatal deaths.
Why Was This Study Done?
If MDG4 is to be met, more must be done to prevent deaths among newborn babies. To improve survival rates and to monitor the effects of public-health interventions in this vulnerable group, accurate, up-to-date estimates of national neonatal mortality rates (NMRs, the number of neonatal deaths per 1,000 live births) are essential. Although infant (under-one) and under-five mortality rates are estimated annually for individual countries by the United Nations Interagency Group for Child Mortality Estimation, annual NMR trend estimates have not been produced before. In many developed countries, child mortality rates can be calculated directly from vital civil registration data—records of all births and deaths. But many developing countries lack vital registration systems and child mortality has to be estimated using data collected in household surveys such as the Demographic and Health Surveys (a project that helps developing countries collect data on health and population trends). In this study, the researchers estimate annual national NMRs and numbers of neonatal deaths for the past 20 years using the available data.
What Did the Researchers Do and Find?
The researchers used civil registration systems, household surveys, and other sources to compile a database of deaths among neonates and children under 5 years old for 193 countries between 1990 and 2009. They estimated NMRs for 38 countries from reliable vital registration data and developed a statistical model to estimate NMRs for the remaining 155 countries (in which 92% of global live births occurred). In 2009, 3.3 million babies died during their first month of life compared to 4.6 million in 1990. More than half the neonatal deaths in 2009 occurred in five countries—India, Nigeria, Pakistan, China, and the Democratic Republic of Congo. India had the largest number of neonatal deaths throughout the study. Between 1990 and 2009, although the global NMR decreased from 33.2 to 23.9 deaths per 1,000 live births (a decrease of 28%), NMRs increased in eight countries, five of which were in Africa. Moreover, in Africa as a whole, the NMR only decreased by 17.6%, from 43.6 per 1,000 live births in 1990 to 35.9 per 1,000 live births in 2009.
What Do These Findings Mean?
These and other findings suggest that neonatal mortality has declined in all world regions since 1990 but that progress has been slowest in the regions with high NMRs such as Africa. Although there is considerable uncertainty around the estimates calculated by the researchers, these findings nevertheless highlight the slow progress in reducing the neonatal mortality risk over the past 20 years and suggest that the relative contribution of neonatal deaths to child deaths will increase into the future. Thus, if MDG4 is to be achieved, it is essential that national governments and international health bodies invest in improved methods for the measurement of neonatal deaths and stillbirths and increase their investment in the provision of care at birth and during the first few weeks of life.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001080.
The United Nations Children's Fund (UNICEF) works for children's rights, survival, development, and protection around the world; it provides information on Millennium Development Goal 4, and its Childinfo Web site provides detailed statistics about child survival and health, including a description of the United Nations Interagency Group for Child Mortality Estimation and a link to its database, and information on newborn care (some information in several languages)
The World Health Organization also has information about the Millennium Development Goal 4, provides information on newborn mortality, and provides the latest estimates of child mortality
Further information about the Millennium Development Goals is available
Information is also available about the Demographic and Health Surveys
doi:10.1371/journal.pmed.1001080
PMCID: PMC3168874  PMID: 21918640

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