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1.  Association between maternal sleep practices and risk of late stillbirth: a case-control study 
Objectives To determine whether snoring, sleep position, and other sleep practices in pregnant women are associated with risk of late stillbirth.
Design Prospective population based case-control study.
Setting Auckland, New Zealand
Participants Cases: 155 women with a singleton late stillbirth (≥28 weeks’ gestation) without congenital abnormality born between July 2006 and June 2009 and booked to deliver in Auckland. Controls: 310 women with single ongoing pregnancies and gestation matched to that at which the stillbirth occurred. Multivariable logistic regression adjusted for known confounding factors.
Main outcome measure Maternal snoring, daytime sleepiness (measured with the Epworth sleepiness scale), and sleep position at the time of going to sleep and on waking (left side, right side, back, and other).
Results The prevalence of late stillbirth in this study was 3.09/1000 births. No relation was found between snoring or daytime sleepiness and risk of late stillbirth. However, women who slept on their back or on their right side on the previous night (before stillbirth or interview) were more likely to experience a late stillbirth compared with women who slept on their left side (adjusted odds ratio for back sleeping 2.54 (95% CI 1.04 to 6.18), and for right side sleeping 1.74 (0.98 to 3.01)). The absolute risk of late stillbirth for women who went to sleep on their left was 1.96/1000 and was 3.93/1000 for women who did not go to sleep on their left. Women who got up to go to the toilet once or less on the last night were more likely to experience a late stillbirth compared with women who got up more frequently (adjusted odds ratio 2.28 (1.40 to 3.71)). Women who regularly slept during the day in the previous month were also more likely to experience a late stillbirth than those who did not (2.04 (1.26 to 3.27)).
Conclusions This is the first study to report maternal sleep related practices as risk factors for stillbirth, and these findings require urgent confirmation in further studies.
PMCID: PMC3114953  PMID: 21673002
2.  The Midland and North of England Stillbirth Study (MiNESS) 
The United Kingdom has one of the highest rates of stillbirth in Europe, resulting in approximately 4,000 stillbirths every year. Potentially modifiable risk factors for late stillbirths are maternal age, obesity and smoking, but the population attributable risk associated with these risk factors is small.
Recently the Auckland Stillbirth Study reported that maternal sleep position was associated with late stillbirth. Women who did not sleep on their left side on the night before the death of the baby had double the risk compared with sleeping on other positions. The population attributable risk was 37%. This novel observation needs to be replicated or refuted.
Case control study of late singleton stillbirths without congenital abnormality. Controls are women with an ongoing singleton pregnancy, who are randomly selected from participating maternity units booking list of pregnant women, they are allocated a gestation for interview based on the distribution of gestations of stillbirths from the previous 4 years for the unit. The number of controls selected is proportional to the number of stillbirths that occurred at the hospital over the previous 4 years.
Data collection: Interviewer administered questionnaire and data extracted from medical records. Sample size: 415 cases and 830 controls. This takes into account a 30% non-participation rate, and will detect an OR of 1.5 with a significance level of 0.05 and power of 80% for variables with a prevalence of 57%, such as non-left sleeping position.
Statistical analysis: Mantel-Haenszel odds ratios and unconditional logistic regression to adjust for potential confounders.
The hypotheses to be tested here are important, biologically plausible and amenable to a public health intervention. Although this case–control study cannot prove causation, there is a striking parallel with research relating to sudden infant death syndrome, where case–control studies identified prone sleeping position as a major modifiable risk factor. Subsequently mothers were advised to sleep babies prone (“Back to Sleep” campaign), which resulted in a dramatic drop in SIDS. This study will provide robust evidence to help determine whether such a public health intervention should be considered.
Trial registration number
PMCID: PMC4032501  PMID: 24885461
Stillbirth; Perinatal mortality; Perinatal death; Risk factors; Sleep position; Reduced fetal movements; Fetal growth restriction
3.  Cesarean Section and Rate of Subsequent Stillbirth, Miscarriage, and Ectopic Pregnancy: A Danish Register-Based Cohort Study 
PLoS Medicine  2014;11(7):e1001670.
Louise Kenny and colleagues conduct a population-based cohort study in Denmark to assess the likelihood of stillbirth, miscarriage, and ectopic pregnancy following cesarean section compared to women who gave birth by vaginal delivery.
Please see later in the article for the Editors' Summary
With cesarean section rates increasing worldwide, clarity regarding negative effects is essential. This study aimed to investigate the rate of subsequent stillbirth, miscarriage, and ectopic pregnancy following primary cesarean section, controlling for confounding by indication.
Methods and Findings
We performed a population-based cohort study using Danish national registry data linking various registers. The cohort included primiparous women with a live birth between January 1, 1982, and December 31, 2010 (n = 832,996), with follow-up until the next event (stillbirth, miscarriage, or ectopic pregnancy) or censoring by live birth, death, emigration, or study end. Cox regression models for all types of cesarean sections, sub-group analyses by type of cesarean, and competing risks analyses for the causes of stillbirth were performed. An increased rate of stillbirth (hazard ratio [HR] 1.14, 95% CI 1.01, 1.28) was found in women with primary cesarean section compared to spontaneous vaginal delivery, giving a theoretical absolute risk increase (ARI) of 0.03% for stillbirth, and a number needed to harm (NNH) of 3,333 women. Analyses by type of cesarean section showed similarly increased rates for emergency (HR 1.15, 95% CI 1.01, 1.31) and elective cesarean (HR 1.11, 95% CI 0.91, 1.35), although not statistically significant in the latter case. An increased rate of ectopic pregnancy was found among women with primary cesarean overall (HR 1.09, 95% CI 1.04, 1.15) and by type (emergency cesarean, HR 1.09, 95% CI 1.03, 1.15, and elective cesarean, HR 1.12, 95% CI 1.03, 1.21), yielding an ARI of 0.1% and a NNH of 1,000 women for ectopic pregnancy. No increased rate of miscarriage was found among women with primary cesarean, with maternally requested cesarean section associated with a decreased rate of miscarriage (HR 0.72, 95% CI 0.60, 0.85). Limitations include incomplete data on maternal body mass index, maternal smoking, fertility treatment, causes of stillbirth, and maternally requested cesarean section, as well as lack of data on antepartum/intrapartum stillbirth and gestational age for stillbirth and miscarriage.
This study found that cesarean section is associated with a small increased rate of subsequent stillbirth and ectopic pregnancy. Underlying medical conditions, however, and confounding by indication for the primary cesarean delivery account for at least part of this increased rate. These findings will assist women and health-care providers to reach more informed decisions regarding mode of delivery.
Please see later in the article for the Editors' Summary
Editors' Summary
Globally, increasing numbers of babies are being delivered by cesarean section (a surgical operation in which the baby is delivered through a cut made in the mother's abdomen and womb) instead of naturally through their mother's vagina. In England in 2010, for example, nearly 25% of all babies were delivered by cesarean section (also called C-section) compared to only 2% in the 1950s; in China and some parts of South America cesarean rates are now between 40% and 50%. A cesarean section is usually performed when a vaginal birth would endanger the life of the mother or her unborn child because, for example, the baby is in the wrong position. Some cesareans are performed as emergency procedures, but others are planned in advance when the need for the operation becomes clear during pregnancy (an elective cesarean). Some planned cesarean sections are also undertaken because the mother has requested a cesarean delivery in the absence of any medical reasons for such a delivery.
Why Was This Study Done?
Cesarean sections save lives but do they have any negative impacts on the outcome of subsequent pregnancies? With so many cesarean sections being undertaken, it is important to be sure that the procedure does not increase the rates of subsequent miscarriage, stillbirth, or ectopic pregnancy. Miscarriage—the loss of a fetus (developing baby) that is unable to survive independently—is the commonest complication of early pregnancy, affecting about one in five women who know they are pregnant. Stillbirth is fetal death after about 20–24 weeks of pregnancy; the exact definition of stillbirth varies between countries. About four million stillbirths occur each year worldwide. Ectopic pregnancy—development of the fetus outside the womb—occurs in 1%–2% of all pregnancies. In this population-based cohort study, the researchers investigate the rates of subsequent stillbirth, miscarriage, and ectopic pregnancy following a cesarean section among women living in Denmark. A population-based cohort study determines the baseline characteristics of the individuals in a population, and then follows the population over time to see whether specific characteristics are associated with specific outcomes.
What Did the Researchers Do and Find?
The researchers obtained data for 832,996 women from Danish national registers about their first live birth (including whether they had a cesarean) then followed the women (again using the registers) until they had a stillbirth, miscarriage, or ectopic pregnancy, or a second live birth. The researchers used these data and statistical models to estimate the risk of stillbirth, miscarriage, and ectopic pregnancy following a cesarean compared to a spontaneous vaginal delivery after controlling for the possibility that the cesarean was performed because of an indication that might increase the risk of a subsequent event (confounding). Women who had had a cesarean had a 14% increased risk of a stillbirth in their next pregnancy compared to women who had had a vaginal delivery, corresponding to an absolute risk increase of 0.03%. In other words, 3,333 women would need to have a cesarean to result in one extra stillbirth in subsequent pregnancy (a “number needed to harm” of 3,333). Compared to vaginal delivery, having a cesarean increased the risk of a subsequent ectopic pregnancy by 9% (an absolute risk increase of 0.1% and a number needed to harm of 1,000) but did not increase the rate of subsequent miscarriages.
What Do These Findings Mean?
These findings show that, among women living in Denmark, cesarean section is associated with a slightly increased rate of subsequent stillbirth and ectopic pregnancy. Part of this increase can be accounted for by underlying medical conditions and by confounding by the indication for the primary cesarean section. The accuracy of these findings may be affected by limitations in the study such as incomplete data on some factors (for example, the smoking history of the mother) that might have affected the risk of stillbirth, miscarriage, and ectopic pregnancy, and by misclassification or underreporting of the study outcomes. Given the global increase in cesarean rates, these findings suggest that cesarean delivery is not associated with an increased rate of subsequent stillbirth, miscarriage, or ectopic pregnancy, an important finding for both expectant mothers and health-care professionals that nonetheless needs to be confirmed in further large-scale studies. Finally, these findings highlight the need for women to consider all their options thoroughly before requesting a cesarean section on non-medical grounds.
Additional Information
Please access these websites via the online version of this summary at
The American Congress of Obstetricians and Gynecologists provides patient fact sheets on cesarean birth, miscarriage, and ectopic pregnancy
The US-based non-profit Nemours Foundation provides information about cesarean sections, miscarriage and stillbirth, and ectopic pregnancy (in English and Spanish)
The UK National Health Service Choices website provides information for patients about cesarean section, miscarriage, stillbirth, and ectopic pregnancy
MedlinePlus provides links to additional resources about cesarean section, miscarriage, stillbirth, and ectopic pregnancy (in English and Spanish)
The UK non-profit organization Healthtalkonline provides personal stories about cesarean delivery, miscarriage, and stillbirth
PMCID: PMC4077571  PMID: 24983970
4.  A triple risk model for unexplained late stillbirth 
The triple risk model for sudden infant death syndrome (SIDS) has been useful in understanding its pathogenesis. Risk factors for late stillbirth are well established, especially relating to maternal and fetal wellbeing.
We propose a similar triple risk model for unexplained late stillbirth. The model proposed by us results from the interplay of three groups of factors: (1) maternal factors (such as maternal age, obesity, smoking), (2) fetal and placental factors (such as intrauterine growth retardation, placental insufficiency), and (3) a stressor (such as venocaval compression from maternal supine sleep position, sleep disordered breathing). We argue that the risk factors within each group in themselves may be insufficient to cause the death, but when they interrelate may produce a lethal combination.
Unexplained late stillbirth occurs when a fetus who is somehow vulnerable dies as a result of encountering a stressor and/or maternal condition in a combination which is lethal for them.
PMCID: PMC3991879  PMID: 24731396
Stillbirth; Triple risk; Vulnerable fetus
5.  Fetal Growth and Risk of Stillbirth: A Population-Based Case–Control Study 
PLoS Medicine  2014;11(4):e1001633.
Radek Bukowski and colleagues conducted a case control study in 59 US hospitals to determine the relationship between fetal growth and stillbirth, and find that both restrictive and excessive growth could play a role.
Please see later in the article for the Editors' Summary
Stillbirth is strongly related to impaired fetal growth. However, the relationship between fetal growth and stillbirth is difficult to determine because of uncertainty in the timing of death and confounding characteristics affecting normal fetal growth.
Methods and Findings
We conducted a population-based case–control study of all stillbirths and a representative sample of live births in 59 hospitals in five geographic areas in the US. Fetal growth abnormalities were categorized as small for gestational age (SGA) (<10th percentile) or large for gestational age (LGA) (>90th percentile) at death (stillbirth) or delivery (live birth) using population, ultrasound, and individualized norms. Gestational age at death was determined using an algorithm that considered the time-of-death interval, postmortem examination, and reliability of the gestational age estimate. Data were weighted to account for the sampling design and differential participation rates in various subgroups. Among 527 singleton stillbirths and 1,821 singleton live births studied, stillbirth was associated with SGA based on population, ultrasound, and individualized norms (odds ratio [OR] [95% CI]: 3.0 [2.2 to 4.0]; 4.7 [3.7 to 5.9]; 4.6 [3.6 to 5.9], respectively). LGA was also associated with increased risk of stillbirth using ultrasound and individualized norms (OR [95% CI]: 3.5 [2.4 to 5.0]; 2.3 [1.7 to 3.1], respectively), but not population norms (OR [95% CI]: 0.6 [0.4 to 1.0]). The associations were stronger with more severe SGA and LGA (<5th and >95th percentile). Analyses adjusted for stillbirth risk factors, subset analyses excluding potential confounders, and analyses in preterm and term pregnancies showed similar patterns of association. In this study 70% of cases and 63% of controls agreed to participate. Analysis weights accounted for differences between consenting and non-consenting women. Some of the characteristics used for individualized fetal growth estimates were missing and were replaced with reference values. However, a sensitivity analysis using individualized norms based on the subset of stillbirths and live births with non-missing variables showed similar findings.
Stillbirth is associated with both growth restriction and excessive fetal growth. These findings suggest that, contrary to current practices and recommendations, stillbirth prevention strategies should focus on both severe SGA and severe LGA pregnancies.
Please see later in the article for the Editors' Summary
Editors' Summary
Pregnancy is usually a happy time, when the parents-to-be anticipate the arrival of a new baby. But, sadly, about 20% of pregnancies end in miscarriage—the early loss of a fetus (developing baby) that is unable to survive independently. Other pregnancies end in stillbirth—fetal death after 20 weeks of pregnancy (in the US; after 24 weeks in the UK). Stillbirths, like miscarriages, are common. In the US, for example, one in every 160 pregnancies ends in stillbirth. How women discover that their unborn baby has died varies. Some women simply know something is wrong and go to hospital to have their fears confirmed. Others find out when a routine check-up detects no fetal heartbeat. Most women give birth naturally after their baby has died, but if the mother's health is at risk, labor may be induced. Common causes of stillbirth include birth defects and infections. Risk factors for stillbirth include being overweight and smoking during pregnancy.
Why Was This Study Done?
Stillbirths are often associated with having a “small for gestational age” (SGA) fetus. Gestation is the period during which a baby develops in its mother's womb. Gestational age is estimated from the date of the woman's last menstrual period and/or from ultrasound scans. An SGA fetus is lighter than expected for its age based on observed distributions (norms) of fetal weights for gestational age. Although stillbirth is clearly associated with impaired fetal growth, the exact relationship between fetal growth and stillbirth remains unclear for two reasons. First, studies investigating this relationship have used gestational age at delivery rather than gestational age at death as an estimate of fetal age, which overestimates the gestational age of stillbirths and leads to errors in estimates of the proportions of SGA and “large for gestational age” (LGA) stillbirths. Second, many characteristics that affect normal fetal growth are also associated with the risk of stillbirth, and this has not been allowed for in previous studies. In this population-based case–control study, the researchers investigate the fetal growth abnormalities associated with stillbirth using a new approach to estimate gestational age and accounting for the effect of characteristics that affect both fetal growth and stillbirth. A population-based case–control study compares the characteristics of patients with a condition in a population with those of unaffected people in the same population.
What Did the Researchers Do and Find?
The researchers investigated all the stillbirths and a sample of live births that occurred over 2.5 years at 59 hospitals in five US regions. They used a formula developed by the Stillbirth Collaborative Research Network to calculate the gestational age at death of the stillbirths. They categorized fetuses as SGA if they had a weight for gestational age within the bottom 10% (below the 10th percentile) of the population and as LGA if they had a weight for gestational age above the 90th percentile at death (stillbirth) or delivery (live birth) using population, ultrasound, and individualized norms of fetal weight for gestational age. Population norms incorporate weights for gestational age from normal pregnancies and from pregnancies complicated by growth abnormalities, whereas the other two norms include weights for gestational age from normal pregnancies only. Having an SGA fetus was associated with a 3- to 4-fold increased risk of stillbirth compared to having a fetus with “appropriate” weight for gestational age based on all three norms. LGA was associated with an increased risk of stillbirth based on the ultrasound and individualized norms but not the population norms. Being more severely SGA or LGA (below the 5th percentile or above the 95th percentile) was associated with an increased risk of stillbirth.
What Do These Findings Mean?
These findings indicate that, when the time of death is accounted for and norms for weight for gestational age only from uncomplicated pregnancies are used, stillbirth is associated with both restricted and excessive fetal growth. Overall, abnormal fetal growth was identified in 25% of stillbirths using population norms and in about 50% of stillbirths using ultrasound or individualized norms. Although the accuracy of these findings is likely to be affected by aspects of the study design, these findings suggest that, contrary to current practices, strategies designed to prevent stillbirth should focus on identifying both severely SGA and severely LGA fetuses and should use norms for the calculation of weight for gestational age based on normal pregnancies only. Such an approach has the potential to identify almost half of the pregnancies likely to result in stillbirth.
Additional Information
Please access these websites via the online version of this summary at
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on stillbirth
Tommy's, a UK nonprofit organization that funds research into stillbirth, premature birth, and miscarriage and provides information for parents-to-be, also provides information on stillbirth (including personal stories)
The UK National Health Service Choices website provides information about stillbirth (including a video about dealing with grief after a stillbirth)
MedlinePlus provides links to other resources about stillbirth (in English and Spanish)
Information about the Stillbirth Collaborative Research Network is available
PMCID: PMC3995658  PMID: 24755550
6.  Predictors of stillbirth among HIV-infected Tanzanian women 
To determine maternal risk factors for stillbirth among pregnant HIV-infected women in sub-Saharan Africa.
Prospective cohort study nested within a micronutrient trial. At enrollment, maternal sociodemographic, obstetric, immunologic, clinical, and nutritional variables were measured. Women were followed through monthly clinic visits until delivery. Multivariate predictors of stillbirth were identified in Poisson regression models.
Antenatal clinic in a tertiary care hospital in urban Dar es Salaam, Tanzania.
N = 1,078 women enrolled between 12 and 27 weeks of gestation.
Main outcome measures
Stillbirth (delivery of dead baby ≥ 28 weeks’ gestation), fresh stillbirth, and macerated stillbirth.
Among 1,017 singleton pregnancies, there were 49 stillbirths, yielding a stillbirth risk of 50.0 per 1,000 deliveries (95% Confidence Interval(CI) = 37.2, 65.6). Of stillbirths with known type, 53.7% were fresh and 46.3% macerated. In multivariate analyses, baseline measures of late ( ≥ 21 weeks’ gestation) study entry (Relative Risk (RR) = 2.13, 95% CI = 1.17, 3.87), CD3 count ≥ 1,179 cells/ml (RR = 2.15, 95% CI = 1.16, 4.01), stillbirth history (RR = 3.53, 95% CI = 1.30, 9.59), primiparity (RR = 3.65, 95% CI = 1.83, 7.29), and syphilis infection (RR = 2.06, 95% CI = 1.09, 3.88) predicted increased stillbirth risk. Late study entry, illiteracy, stillbirth history, primiparity, CD3 count ≥ 1,179 cells/ml, gonorrhea infection, and previous hospitalization predicted increased risk of fresh stillbirth, while living alone and syphilis infection predicted increased risk of macerated stillbirth.
Applying antenatal screening and preventive tools for the socioeconomic, obstetric, immunologic, and clinical risk factors identified may assist in reducing the high incidence of stillbirth among HIV-infected women in urban sub-Saharan Africa.
PMCID: PMC2796303  PMID: 19306132
Predictors; pregnancy; HIV; stillbirth; Tanzania
7.  Relationship between obesity, ethnicity and risk of late stillbirth: a case control study 
In high income countries there has been little improvement in stillbirth rates over the past two decades. Previous studies have indicated an ethnic disparity in the rate of stillbirths. This study aimed to determine whether maternal ethnicity is independently associated with late stillbirth in New Zealand.
Cases were women with a singleton, late stillbirth (≥28 weeks' gestation) without congenital abnormality, born between July 2006 and June 2009 in Auckland, New Zealand. Two controls with ongoing pregnancies were randomly selected at the same gestation at which the stillbirth occurred. Women were interviewed in the first few weeks following stillbirth, or at the equivalent gestation for controls. Detailed demographic data were recorded. The study was powered to detect an odds ratio of 2, with a power of 80% at the 5% level of significance, given a prevalence of the risk factor of 20%. A multivariable regression model was developed which adjusted for known risk factors for stillbirth, as well as significant risk factors identified in the current study, and adjusted odds ratios and 95% confidence intervals were calculated.
155/215 (72%) cases and 310/429 (72%) controls consented. Pacific ethnicity, overweight and obesity, grandmultiparity, not being married, not being in paid work, social deprivation, exposure to tobacco smoke and use of recreational drugs were associated with an increased risk of late stillbirth in univariable analysis. Maternal overweight and obesity, nulliparity, grandmultiparity, not being married and not being in paid work were independently associated with late stillbirth in multivariable analysis, whereas Pacific ethnicity was no longer significant (adjusted Odds Ratio 0.99; 0.51-1.91).
Pacific ethnicity was not found to be an independent risk factor for late stillbirth in this New Zealand study. The disparity in stillbirth rates between Pacific and European women can be attributed to confounding factors such as maternal obesity and high parity.
PMCID: PMC3027197  PMID: 21226915
8.  Reducing stillbirths: screening and monitoring during pregnancy and labour 
BMC Pregnancy and Childbirth  2009;9(Suppl 1):S5.
Screening and monitoring in pregnancy are strategies used by healthcare providers to identify high-risk pregnancies so that they can provide more targeted and appropriate treatment and follow-up care, and to monitor fetal well-being in both low- and high-risk pregnancies. The use of many of these techniques is controversial and their ability to detect fetal compromise often unknown. Theoretically, appropriate management of maternal and fetal risk factors and complications that are detected in pregnancy and labour could prevent a large proportion of the world's 3.2 million estimated annual stillbirths, as well as minimise maternal and neonatal morbidity and mortality.
The fourth in a series of papers assessing the evidence base for prevention of stillbirths, this paper reviews available published evidence for the impact of 14 screening and monitoring interventions in pregnancy on stillbirth, including identification and management of high-risk pregnancies, advanced monitoring techniques, and monitoring of labour. Using broad and specific strategies to search PubMed and the Cochrane Library, we identified 221 relevant reviews and studies testing screening and monitoring interventions during the antenatal and intrapartum periods and reporting stillbirth or perinatal mortality as an outcome.
We found a dearth of rigorous evidence of direct impact of any of these screening procedures and interventions on stillbirth incidence. Observational studies testing some interventions, including fetal movement monitoring and Doppler monitoring, showed some evidence of impact on stillbirths in selected high-risk populations, but require larger rigourous trials to confirm impact. Other interventions, such as amniotic fluid assessment for oligohydramnios, appear predictive of stillbirth risk, but studies are lacking which assess the impact on perinatal mortality of subsequent intervention based on test findings. Few rigorous studies of cardiotocography have reported stillbirth outcomes, but steep declines in stillbirth rates have been observed in high-income settings such as the U.S., where cardiotocography is used in conjunction with Caesarean section for fetal distress.
There are numerous research gaps and large, adequately controlled trials are still needed for most of the interventions we considered. The impact of monitoring interventions on stillbirth relies on use of effective and timely intervention should problems be detected. Numerous studies indicated that positive tests were associated with increased perinatal mortality, but while some tests had good sensitivity in detecting distress, false-positive rates were high for most tests, and questions remain about optimal timing, frequency, and implications of testing. Few studies included assessments of impact of subsequent intervention needed before recommending particular monitoring strategies as a means to decrease stillbirth incidence. In high-income countries such as the US, observational evidence suggests that widespread use of cardiotocography with Caesarean section for fetal distress has led to significant declines in stillbirth rates. Efforts to increase availability of Caesarean section in low-/middle-income countries should be coupled with intrapartum monitoring technologies where resources and provider skills permit.
PMCID: PMC2679411  PMID: 19426468
American journal of obstetrics and gynecology  2013;208(4):287.e1-287.e15.
To determine if maternal plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor-1 (sVEGFR-1) at 30–34 weeks can identify mothers at risk for preeclampsia (PE), stillbirth and small-for-gestational-age neonates (SGA).
A prospective cohort study included 1269 singleton pregnant women who had blood samples obtained at 30–34 weeks and delivered after 34 weeks of gestation. Plasma concentrations of PlGF, sEng, and sVEGFR-1 were determined by ELISA.
The prevalence of late (>34 weeks) PE, severe late PE, stillbirth and SGA was 3.2% (n=40), 1.8% (n=23), 0.4% (n=5) and 8.5% (n=108), respectively. A plasma concentration of PlGF/sEng <0.3 MoM was associated with severe late PE [adjusted odds ratio (aOR) 16]; addition of PlGF/sEng to clinical risk factors increased the area under the ROC curve (AUC) from 0.76 to 0.88 (p=0.03). The ratio of PlGF/sEng or PlGF/sVEGFR-1 in the third trimester outperformed those obtained in the first or second trimester and uterine artery Doppler velocimetry at 20–25 weeks for the prediction of severe late PE (comparison of AUC; each p≤0.02). Both PlGF/sEng and PlGF/sVEGFR-1 ratios achieved a sensitivity of 74% with a fixed false positive rate of 15% for the identification of severe late PE. A plasma concentration of PlGF/sVEGFR-1 <0.12 MoM at 30–34 weeks had a sensitivity of 80%, a specificity of 94%, and a likelihood ratio of a positive test of 14 for the identification of subsequent stillbirth. Similar findings (sensitivity 80% and specificity 93%) were observed in a separate case-control study. Integrating these biomarkers with clinical data did not improve the prediction of SGA.
Risk assessment for severe late PE and stillbirth in the third trimester is possible with the determination of maternal plasma concentrations of angiogenic and anti-angiogenic factors at 30–34 weeks of gestation.
PMCID: PMC4086897  PMID: 23333542
fetal death; placental growth factor (PlGF); soluble endoglin (sEng); soluble vascular endothelial growth factor receptor-1 (sVEGFR-1); severe preeclampsia; SGA
10.  Global report on preterm birth and stillbirth (1 of 7): definitions, description of the burden and opportunities to improve data 
BMC Pregnancy and Childbirth  2010;10(Suppl 1):S1.
This is the first of seven articles from a preterm birth and stillbirth report. Presented here is an overview of the burden, an assessment of the quality of current estimates, review of trends, and recommendations to improve data.
Preterm birth
Few countries have reliable national preterm birth prevalence data. Globally, an estimated 13 million babies are born before 37 completed weeks of gestation annually. Rates are generally highest in low- and middle-income countries, and increasing in some middle- and high-income countries, particularly the Americas. Preterm birth is the leading direct cause of neonatal death (27%); more than one million preterm newborns die annually. Preterm birth is also the dominant risk factor for neonatal mortality, particularly for deaths due to infections. Long-term impairment is an increasing issue.
Stillbirths are currently not included in Millennium Development Goal tracking and remain invisible in global policies. For international comparisons, stillbirths include late fetal deaths weighing more than 1000g or occurring after 28 weeks gestation. Only about 2% of all stillbirths are counted through vital registration and global estimates are based on household surveys or modelling. Two global estimation exercises reached a similar estimate of around three million annually; 99% occur in low- and middle-income countries. One million stillbirths occur during birth. Global stillbirth cause-of-death estimates are impeded by multiple, complex classification systems.
Recommendations to improve data
(1) increase the capture and quality of pregnancy outcome data through household surveys, the main data source for countries with 75% of the global burden; (2) increase compliance with standard definitions of gestational age and stillbirth in routine data collection systems; (3) strengthen existing data collection mechanisms—especially vital registration and facility data—by instituting a standard death certificate for stillbirth and neonatal death linked to revised International Classification of Diseases coding; (4) validate a simple, standardized classification system for stillbirth cause-of-death; and (5) improve systems and tools to capture acute morbidity and long-term impairment outcomes following preterm birth.
Lack of adequate data hampers visibility, effective policies, and research. Immediate opportunities exist to improve data tracking and reduce the burden of preterm birth and stillbirth.
PMCID: PMC2841772  PMID: 20233382
11.  Endocrine Profiles, Haematology and Pregnancy Outcomes of Late Pregnant Holstein Dairy Heifers Sired by Bulls Giving a High or Low Incidence of Stillbirth 
Acta Veterinaria Scandinavica  2004;45(1):47-68.
The high incidence of stillbirth in Swedish Holstein heifers has increased continuously during the last 15 years to an average of 11% today. The pathological reasons behind the increased incidence of stillbirth are unknown. The present experiment was undertaken to investigate possible causes of stillbirth and to study possible physiological markers for predicting stillbirth. Twenty Swedish Holstein dairy heifers sired by bulls with breeding values for a high risk of stillbirth (n = 12) (experimental group) and a low risk of stillbirth (n = 8) (control group, group B) were selected based on information in the Swedish AI-data base. The experimental group consisted of 2 subgroups of heifers (groups A1 and A2) inseminated with 2 different bulls with 3.5% and 9% higher stillbirth rates than the average, and the control group consisted of heifers pregnant with 5 different bulls with 0%–6% lower stillbirth rates than the average. The bull used for group A1 had also calving difficulties due to large calves as compared to the bull in group A2 showing no calving difficulties. The heifers were supervised from 6–7 months of pregnancy up to birth, and the pregnancies and parturitions were compared between groups regarding hormonal levels, haematology, placental characteristics and calf viability. In group A1, 1 stillborn, 1 weak and 4 normal calves were recorded. In group A2, 2 stillborn and 4 normal calves were registered. All animals in the control group gave birth to a normal living calf without any assistance. The weak calf showed deviating profiles of body temperature, saturated oxygen and heart rates, compared with the normal living calves. No differences of the placentome thickness, measured in vivo by ultrasonography were seen between the groups. The number of leukocytes and differential cell counts in groups A1 and A2 followed the profiles found in the control group. In group A1, a slight decrease of oestrone sulphate (E1SO4) levels was found in the animal delivering a stillborn calf from the first 24-h blood sampling at 6 weeks to the second at 3 weeks prior to delivery, while the levels of E1SO4 at both periods in the animal delivering a weak calf followed the profile in animals delivering a normal living calf. During late pregnancy and at the time of parturition, the levels of E1SO4 and PAGs in animals delivering a stillborn or weak calf (from group A1) followed the normal profiles found in animals delivering a normal living calf. In group A2, low levels of E1SO4 and pregnancy associated glycoproteins (PAGs) over 24 h at both 3 and 6 weeks prior to parturition (<1.5 nmol/L) were recorded in animals delivering a stillborn calf. During late pregnancy and parturition, the levels of E1SO4 and PAGs were slightly lower during 30–50 days prior to delivery and increased with a lower magnitude at the time of parturition. In conclusion, our results indicate that the aetiology behind stillbirth varies depending on the AI-bulls used and is associated with dystocia or low viability of the calves. Deviating profiles of oestrone sulphate (E1SO4) and pregnancy associated glycoproteins (PAGs) in animals delivering a stillborn calf not caused by dystocia were observed, suggesting placental dysfunction as a possible factor. The finding suggests that the analyses of E1SO4 and PAGs could be used for monitoring foetal well-being in animals with a high risk of stillbirth at term.
PMCID: PMC1820998  PMID: 15535086
Cattle-pregnancy; parturition; endocrine profiles; haematology; placental characteristics; foetal well-being
12.  Commentary: reducing the world's stillbirths 
BMC Pregnancy and Childbirth  2009;9(Suppl 1):S1.
One of the major success stories of modern obstetrics in high-income countries in the last 5 decades is the reduction of stillbirths from rates as high as 50 per 1000 births to about 5 per 1000 births today. Fetal mortality associated with obstructed labour, asphyxia, hypertension, diabetes, Rh disease, placental abruption, post-term pregnancies and infections such as syphilis all have declined. Much of this success has occurred in term births in the intrapartum period so that most stillbirths in high-income countries now occur in the antepartum period and are pre-term. Current stillbirth rates in many low- and middle-income countries, and especially in those areas within the countries with poorly functioning health systems, approximate those seen in high-income countries 50 years ago. A major difference between the stillbirths occurring in high-income countries and those occurring elsewhere is the preponderance of late pre-term, term and intrapartum stillbirths in low-resource countries. Those stillbirths should be relatively easy to prevent by known risk assessment methods and prompt delivery, often by Cesarean section. This commentary addresses an extensive six-paper review of stillbirths with an emphasis on low- and middle-income countries. Among the conclusions are that while a number of interventions have been shown to be effective in reducing stillbirths, unless there is a functioning health system in which these interventions can be implemented, the potential for a sustainable and substantial reduction in stillbirth rates will not be reached.
PMCID: PMC2679407  PMID: 19426464
13.  Risk of stillbirth from occupational and residential exposures. 
OBJECTIVES: To analyse the risk of stillbirth from 12 residential and occupational maternal exposures during pregnancy. METHODS: Stillbirths and neonatal deaths in 1984 within 24 hours of birth from 10 California counties were identified from death certificates. Controls were randomly selected from live births born in 1984 and frequency matched to cases by maternal age and county. Data sources included vital statistics and a self-administered postal questionnaire. Logistic regression and proportional hazards modelling were performed; the proportional hazards considered the truncated opportunity for exposure among cases. Special focus was given to two cause of deaths groups: congenital anomalies (12% of deaths) and complications of the placenta, cord, and membranes (37% of deaths). RESULTS: Occupational exposure to pesticides during the first two months of gestation was positively associated with stillbirths due to congenital anomalies (odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0 to 5.9), and during the first and second trimesters with stillbirths due to all causes of death (risk ratios (RR) 1.3-1.4, 95% CI 1.0 to 1.7) and stillbirths due to complications of the placenta, cord, and membranes (RR 1.6-1.7, 95% CI 1.1 to 2.3). Occupational exposure to video display terminals in the third trimester was found to have a modest inverse association with stillbirths (RR 0.7, 95% CI 0.6, 0.9). Home pesticide exposure was positively associated with stillbirths due to congenital anomalies (OR 1.7, 95% CI 1.0 to 2.9). CONCLUSIONS: Occupational exposure to pesticides, especially during early pregnancy, had a clear positive association with stillbirths regardless of cause of death. Methodologically, this study of stillbirths is unique in its analysis of specific causes of death and use of time specific exposure windows.
PMCID: PMC1128822  PMID: 9282129
14.  Accuracy of Self-Reported Sleep Position in Late Pregnancy 
PLoS ONE  2014;9(12):e115760.
There is emerging research to suggest that supine maternal sleep position in late pregnancy may adversely affect fetal wellbeing. However, these studies have all been based on maternal report of sleeping position. Before recommendations to change sleep position can be made it is important to determine the validity of these studies by investigating how accurate pregnant women are in reporting their sleep position. If avoiding the supine sleeping position reduces risk of poor pregnancy outcome, it is also important to know how well women can comply with the instruction to avoid this position and sleep on their left.
Thirty women in late pregnancy participated in a three-night observational study and were asked to report their sleeping position. This was compared to sleep position as recorded by a night capable video recording. The participants were instructed to settle to sleep on their left side and if they woke overnight to settle back to sleep on their left.
There was a moderate correlation between reported and video-determined left-side sleep time (r = 0.48), mean difference = 3 min (SD = 3.5 h). Participants spent an average of 59.60% (SD = 16.73%) of time in bed on their left side (ICC across multiple nights = 0.67). Those who included left side among their typical sleep positions reported significantly longer sleep during the study (p<0.01).
On average participant reports of sleep position were relatively accurate but there were large individual differences in reporting accuracy and in objectively-determined time on left side. Night-to-night consistency was substantial. For those who do not ordinarily sleep on that side, asking participants to sleep on their left may result in reduced sleep duration. This is an important consideration during a sleep-critical time such as late pregnancy.
PMCID: PMC4275245  PMID: 25535960
15.  Association of maternal sleep practices with pre-eclampsia, low birth weight, and stillbirth among Ghanaian women 
To assess sleep practices, and investigate their relationship with maternal and fetal outcomes, among pregnant Ghanaian women.
In a cross-sectional study conducted at Korle Bu Teaching Hospital, Accra, Ghana, between June and July 2011, postpartum women were interviewed within 48 hours of delivery about sleep quality and practices during pregnancy. Interviews were coupled with a systematic review of participants’ medical charts for key outcomes including maternal hypertension, pre-eclampsia, premature delivery, low birth weight, and stillbirth.
Most women reported poor sleep quality during pregnancy. Snoring during pregnancy was independently associated with pre-eclampsia (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.4–8.5; P=0.007). The newborns of women who reported supine sleep during pregnancy were at increased risk of low birth weight (OR, 5.0; 95% CI, 1.2–20.2; P=0.025) and stillbirth (OR, 8.0; 95% CI, 1.5–43.2; P=0.016). Low birth weight was found to mediate the relationship between supine sleep and stillbirth.
The present findings in an African population demonstrate that maternal sleep, a modifiable risk factor, has a significant role in pre-eclampsia, low birth weight, and subsequently stillbirth.
PMCID: PMC3662549  PMID: 23507553
Africa; Low birth weight; Pre-eclampsia; Sleep position; Sleep quality; Snoring; Stillbirth
16.  Trends in socioeconomic inequalities in risk of sudden infant death syndrome, other causes of infant mortality, and stillbirth in Scotland: population based study 
Objectives To compare changes in inequalities in sudden infant death syndrome with other causes of infant mortality and stillbirth in Scotland, 1985-2008.
Design Retrospective cohort study.
Setting Scotland 1985-2008, analysed by four epochs of six years.
Participants Singleton births of infants with birth weight >500 g born at 28-43 weeks’ gestation.
Main outcome measures Sudden infant death syndrome, other causes of postneonatal infant death, neonatal death, and stillbirth. Odds ratios expressed as the association across the range of seven categories of Carstairs deprivation score.
Results The association between deprivation and the risk of all cause stillbirth and infant death varied between the four epochs (P=0.04). This was wholly explained by variation in the risk of sudden infant death syndrome (P<0.001 for interaction). Among women living in areas of low deprivation, there was a sharp decline in the rate of sudden infant death syndrome from 1990 to 1993. Among women living in areas of high deprivation, there was a slower decline in sudden infant death syndrome rates between 1992 and 2004. Consequently, the odds ratio for the association between socioeconomic deprivation and sudden infant death syndrome increased from 2.04 (95% confidence interval 1.53 to 2.72) in 1985-90, to 7.52 (4.62 to 12.25) in 1991-6, and 9.50 (5.46 to 16.53) in 1997-2002 but fell to 1.78 (0.87 to 3.65) in 2002-8. The interaction remained significant after adjustment for maternal characteristics.
Conclusion The rate of sudden infant death syndrome declined throughout Scotland in the early 1990s. The decline had a later onset and was slower among women living in areas of high deprivation, probably because of slower uptake of recommended changes in infant sleeping position. The effect was to create a strong independent association between deprivation and sudden infant death syndrome where one did not exist before.
PMCID: PMC3307809  PMID: 22427307
17.  Association Between Stillbirth and Risk Factors Known at Pregnancy Confirmation 
JAMA : the journal of the American Medical Association  2011;306(22):10.1001/jama.2011.1798.
Stillbirths account for almost half of US deaths from 20 weeks’ gestation to 1 year of life. Most large studies of risk factors for stillbirth use vital statistics with limited data.
To determine the relation between stillbirths and risk factors that could be ascertained at the start of pregnancy, particularly the contribution of these factors to racial disparities.
Design, Setting, and Participants
Multisite population-based case-control study conducted between March 2006 and September 2008. Fifty-nine US tertiary care and community hospitals, with access to at least 90% of deliveries within 5 catchment areas defined by state and county lines, enrolled residents with deliveries of 1 or more stillborn fetuses and a representative sample of deliveries of only live-born infants, over-sampled for those at less than 32 weeks’ gestation and those of African descent.
Main Outcome Measure
Analysis included 614 case and 1816 control deliveries. In multivariate analyses, the following factors were independently associated with stillbirth: non-Hispanic black race/ethnicity (23.1% stillbirths, 11.2% live births) (vs non-Hispanic whites; adjusted odds ratio [AOR], 2.12 [95% CI, 1.41–3.20]); previous stillbirth (6.7% stillbirths, 1.4% live births); nulliparity with (10.5% stillbirths, 5.2% live births) and without (34.0% stillbirths, 29.7% live births) previous losses at fewer than 20 weeks’ gestation (vs multiparity without stillbirth or previous losses; AOR, 5.91 [95% CI, 3.18–11.00]; AOR, 3.13 [95% CI, 2.06–4.75]; and AOR, 1.98 [95% CI, 1.51–2.60], respectively); diabetes (5.6% stillbirths, 1.6% live births) (vs no diabetes; AOR, 2.50 [95% CI, 1.39–4.48]); maternal age 40 years or older (4.5% stillbirths, 2.1% live births) (vs age 20–34 years; AOR, 2.41 [95% CI, 1.24–4.70]); maternal AB blood type (4.9% stillbirths, 3.0% live births) (vs type O; AOR, 1.96 [95% CI, 1.16–3.30]); history of drug addiction (4.5% stillbirths, 2.1% live births) (vs never use; AOR, 2.08 [95% CI, 1.12–3.88]); smoking during the 3 months prior to pregnancy (<10 cigarettes/d, 10.0% stillbirths, 6.5% live births) (vs none; AOR, 1.55 [95% CI, 1.02–2.35]); obesity/overweight (15.5% stillbirths, 12.4% live births) (vs normal weight; AOR, 1.72 [95% CI, 1.22–2.43]); not living with a partner (25.4% stillbirths, 15.3% live births) (vs married; AOR, 1.62 [95% CI, 1.15–2.27]); and plurality (6.4% stillbirths, 1.9% live births) (vs singleton; AOR, 4.59 [95% CI, 2.63–8.00]). The generalized R2 was 0.19, explaining little of the variance.
Multiple risk factors that would have been known at the time of pregnancy confirmation were associated with stillbirth but accounted for only a small amount of the variance in this outcome.
PMCID: PMC3807602  PMID: 22166606
18.  Sleep-Disordered Breathing and Mortality: A Prospective Cohort Study 
PLoS Medicine  2009;6(8):e1000132.
In a cohort of 6,441 volunteers followed over an average of 8.2 years, Naresh Punjabi and colleagues find sleep-disordered breathing to be independently associated with mortality and identify predictive characteristics.
Sleep-disordered breathing is a common condition associated with adverse health outcomes including hypertension and cardiovascular disease. The overall objective of this study was to determine whether sleep-disordered breathing and its sequelae of intermittent hypoxemia and recurrent arousals are associated with mortality in a community sample of adults aged 40 years or older.
Methods and Findings
We prospectively examined whether sleep-disordered breathing was associated with an increased risk of death from any cause in 6,441 men and women participating in the Sleep Heart Health Study. Sleep-disordered breathing was assessed with the apnea–hypopnea index (AHI) based on an in-home polysomnogram. Survival analysis and proportional hazards regression models were used to calculate hazard ratios for mortality after adjusting for age, sex, race, smoking status, body mass index, and prevalent medical conditions. The average follow-up period for the cohort was 8.2 y during which 1,047 participants (587 men and 460 women) died. Compared to those without sleep-disordered breathing (AHI: <5 events/h), the fully adjusted hazard ratios for all-cause mortality in those with mild (AHI: 5.0–14.9 events/h), moderate (AHI: 15.0–29.9 events/h), and severe (AHI: ≥30.0 events/h) sleep-disordered breathing were 0.93 (95% CI: 0.80–1.08), 1.17 (95% CI: 0.97–1.42), and 1.46 (95% CI: 1.14–1.86), respectively. Stratified analyses by sex and age showed that the increased risk of death associated with severe sleep-disordered breathing was statistically significant in men aged 40–70 y (hazard ratio: 2.09; 95% CI: 1.31–3.33). Measures of sleep-related intermittent hypoxemia, but not sleep fragmentation, were independently associated with all-cause mortality. Coronary artery disease–related mortality associated with sleep-disordered breathing showed a pattern of association similar to all-cause mortality.
Sleep-disordered breathing is associated with all-cause mortality and specifically that due to coronary artery disease, particularly in men aged 40–70 y with severe sleep-disordered breathing.
Please see later in the article for the Editors' Summary
Editors' Summary
About 1 in 10 women and 1 in 4 men have a chronic condition called sleep-disordered breathing although most are unaware of their problem. Sleep-disordered breathing, which is commonest in middle-aged and elderly people, is characterized by numerous, brief (10 second or so) interruptions of breathing during sleep. These interruptions, which usually occur when relaxation of the upper airway muscles decreases airflow, lower the level of oxygen in the blood and, as a result, affected individuals are frequently aroused from deep sleep as they struggle to breathe. Symptoms of sleep-disordered breathing include loud snoring and daytime sleepiness. Treatments include lifestyle changes such as losing weight (excess fat around the neck increases airway collapse) and smoking cessation. Affected people can also use special devices to prevent them sleeping on their backs, but for severe sleep-disordered breathing, doctors often recommend continuous positive airway pressure (CPAP), a machine that pressurizes the upper airway through a face mask to keep it open.
Why Was This Study Done?
Sleep-disordered breathing is a serious condition. It is associated with several adverse health conditions including coronary artery disease (narrowing of the blood vessels that supply the heart, a condition that can cause a heart attack) and daytime sleepiness that can affect an individual's driving ability. In addition, several clinic- and community-based studies suggest that sleep-disordered sleeping may increase a person's risk of dying. However, because these studies have been small and have often failed to allow for other conditions and characteristics that affect an individual's risk of dying (“confounding factors”), they provide inconsistent or incomplete information about the potential association between sleep-disordered breathing and the risk of death. In this prospective cohort study (part of the Sleep Heart Health Study, which is researching the effects of sleep-disordered breathing on cardiovascular health), the researchers examine whether sleep-disordered breathing is associated with all-cause mortality (death from any cause) in a large community sample of adults. A prospective cohort study is one in which a group of participants is enrolled and then followed forward in time (in this case for several years) to see what happens to them.
What Did the Researchers Do and Find?
At enrollment, the study participants—more than 6,000 people aged 40 years or older, none of whom were being treated for sleep-disordered breathing—had a health examination. Their night-time breathing, sleep patterns, and blood oxygen levels were also assessed and these data used to calculate each participant's apnea-hypopnea index (AHI)—the number of apneas and hypopneas per hour. During the study follow-up period, 1,047 participants died. Compared to participants without sleep-disordered sleeping, participants with severe sleep-disordered breathing (an AHI of ≥30) were about one and a half times as likely to die from any cause after adjustment for potential confounding factors. People with milder sleep-disordered breathing did not have a statistically significant increased risk of dying. After dividing the participants into subgroups according to their age and sex, men aged 40–70 years with severe sleep-disordered breathing had a statistically increased risk of dying from any cause (twice the risk of men of a similar age without sleep-disordered breathing). Finally, death from coronary artery disease was also associated with sleep-disordered breathing in men but not in women.
What Do These Findings Mean?
These findings indicate that sleep-disordered breathing is associated with an increased risk of all-cause mortality, particularly in men aged 40–70 years, even after allowing for known confounding factors. They also suggest that the increased risk of death is specifically associated with coronary artery disease although further studies are needed to confirm this finding because it was based on the analysis of a small subgroup of study participants. Although this study is much larger than previous investigations into the association between sleep-disordered breathing and all-cause mortality, it has several limitations including its reliance on a single night's measurements for the diagnosis of sleep-disordered breathing. Nevertheless, these findings suggest that clinical trials should now be started to assess whether treatment can reduce the increased risk of death that seems to be associated with this common disorder.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Heart Lung and Blood Institute has information (including a video) about sleep-disordered breathing (sleep apnea) (in English and Spanish)
The UK National Heath Service also provides information for patients about sleep apnea
MedlinePlus provides links to further information and advice about sleep-disordered breathing (in English and Spanish)
More information on the Sleep Heart Health Study is available
PMCID: PMC2722083  PMID: 19688045
19.  Association Between Stillbirth and Illicit Drug Use and Smoking During Pregnancy 
Obstetrics and gynecology  2014;123(1):113-125.
To compare illicit drug and smoking use in pregnancies with and without stillbirth.
The Stillbirth Collaborative Research Network conducted a case-control study from March 2006 to September 2008, covering more than 90% of deliveries to residents of five a priori defined geographically diverse regions. The study attempted to include all stillbirths and representative liveborn controls. Umbilical cord samples from cases and controls were collected and frozen for subsequent batch analysis. Maternal serum was collected at delivery and batch analyzed for cotinine.
For 663 stillbirth deliveries, 418 (63%) had cord homogenate and 579 (87%) had maternal cotinine assays performed. For 1,932 live birth deliveries, 1,050 (54%) had cord homogenate toxicology and 1,545 (80%) had maternal cotinine assays performed. A positive cord homogenate test for any illicit drug was associated with stillbirth (OR 1.94; 95% CI 1.16, 3.27). The most common individual drug was cannabis (OR 2.34; 95% CI 1.13, 4.81), although the effect was partially confounded by smoking. Both maternal self-reported smoking history and maternal serum cotinine levels were associated in a dose-response relationship with stillbirth. Positive serum cotinine < 3 ng/ml and no reported history of smoking (proxy for passive smoke exposure) also was associated with stillbirth (OR 2.06; 95% CI 1.24, 3.41).
Cannabis, smoking, illicit drug use, and apparent exposure to second-hand smoke, separately or in combination, during pregnancy were associated with an increased risk of stillbirth. As cannabis use may be increasing with increased legalization, the relevance of these findings may increase as well.
PMCID: PMC3931517  PMID: 24463671
20.  Polysomnography in Patients With Obstructive Sleep Apnea 
Executive Summary
The objective of this health technology policy assessment was to evaluate the clinical utility and cost-effectiveness of sleep studies in Ontario.
Clinical Need: Target Population and Condition
Sleep disorders are common and obstructive sleep apnea (OSA) is the predominant type. Obstructive sleep apnea is the repetitive complete obstruction (apnea) or partial obstruction (hypopnea) of the collapsible part of the upper airway during sleep. The syndrome is associated with excessive daytime sleepiness or chronic fatigue. Several studies have shown that OSA is associated with hypertension, stroke, and other cardiovascular disorders; many researchers believe that these cardiovascular disorders are consequences of OSA. This has generated increasing interest in recent years in sleep studies.
The Technology Being Reviewed
There is no ‘gold standard’ for the diagnosis of OSA, which makes it difficult to calibrate any test for diagnosis. Traditionally, polysomnography (PSG) in an attended setting (sleep laboratory) has been used as a reference standard for the diagnosis of OSA. Polysomnography measures several sleep variables, one of which is the apnea-hypopnea index (AHI) or respiratory disturbance index (RDI). The AHI is defined as the sum of apneas and hypopneas per hour of sleep; apnea is defined as the absence of airflow for ≥ 10 seconds; and hypopnea is defined as reduction in respiratory effort with ≥ 4% oxygen desaturation. The RDI is defined as the sum of apneas, hypopneas, and abnormal respiratory events per hour of sleep. Often the two terms are used interchangeably. The AHI has been widely used to diagnose OSA, although with different cut-off levels, the basis for which are often unclear or arbitrarily determined. Generally, an AHI of more than five events per hour of sleep is considered abnormal and the patient is considered to have a sleep disorder. An abnormal AHI accompanied by excessive daytime sleepiness is the hallmark for OSA diagnosis. For patients diagnosed with OSA, continuous positive airway pressure (CPAP) therapy is the treatment of choice. Polysomnography may also used for titrating CPAP to individual needs.
In January 2005, the College of Physicians and Surgeons of Ontario published the second edition of Independent Health Facilities: Clinical Practice Parameters and Facility Standards: Sleep Medicine, commonly known as “The Sleep Book.” The Sleep Book states that OSA is the most common primary respiratory sleep disorder and a full overnight sleep study is considered the current standard test for individuals in whom OSA is suspected (based on clinical signs and symptoms), particularly if CPAP or surgical therapy is being considered.
Polysomnography in a sleep laboratory is time-consuming and expensive. With the evolution of technology, portable devices have emerged that measure more or less the same sleep variables in sleep laboratories as in the home. Newer CPAP devices also have auto-titration features and can record sleep variables including AHI. These devices, if equally accurate, may reduce the dependency on sleep laboratories for the diagnosis of OSA and the titration of CPAP, and thus may be more cost-effective.
Difficulties arise, however, when trying to assess and compare the diagnostic efficacy of in-home PSG versus in-lab. The AHI measured from portable devices in-home is the sum of apneas and hypopneas per hour of time in bed, rather than of sleep, and the absolute diagnostic efficacy of in-lab PSG is unknown. To compare in-home PSG with in-lab PSG, several researchers have used correlation coefficients or sensitivity and specificity, while others have used Bland-Altman plots or receiver operating characteristics (ROC) curves. All these approaches, however, have potential pitfalls. Correlation coefficients do not measure agreement; sensitivity and specificity are not helpful when the true disease status is unknown; and Bland-Altman plots measure agreement (but are helpful when the range of clinical equivalence is known). Lastly, receiver operating characteristics curves are generated using logistic regression with the true disease status as the dependent variable and test values as the independent variable. Thus, each value of the test is used as a cut-point to measure sensitivity and specificity, which are then plotted on an x-y plane. The cut-point that maximizes both sensitivity and specificity is chosen as the cut-off level to discriminate between disease and no-disease states. In the absence of a gold standard to determine the true disease status, ROC curves are of minimal value.
At the request of the Ontario Health Technology Advisory Committee (OHTAC), MAS has thus reviewed the literature on PSG published over the last two years to examine new developments.
Review Strategy
There is a large body of literature on sleep studies and several reviews have been conducted. Two large cohort studies, the Sleep Heart Health Study and the Wisconsin Sleep Cohort Study, are the main sources of evidence on sleep literature.
To examine new developments on PSG published in the past two years, MEDLINE, EMBASE, MEDLINE In-Process & Other Non-Indexed Citations, the Cochrane Database of Systematic Reviews and Cochrane CENTRAL, INAHTA, and websites of other health technology assessment agencies were searched. Any study that reported results of in-home or in-lab PSG was included. All articles that reported findings from the Sleep Heart Health Study and the Wisconsin Sleep Cohort Study were also reviewed.
Diffusion of Sleep Laboratories
To estimate the diffusion of sleep laboratories, a list of sleep laboratories licensed under the Independent Health Facility Act was obtained. The annual number of sleep studies per 100,000 individuals in Ontario from 2000 to 2004 was also estimated using administrative databases.
Summary of Findings
Literature Review
A total of 315 articles were identified that were published in the past two years; 227 were excluded after reviewing titles and abstracts. A total of 59 articles were identified that reported findings of the Sleep Heart Health Study and the Wisconsin Sleep Cohort Study.
Based on cross-sectional data from the Wisconsin Sleep Cohort Study of 602 men and women aged 30 to 60 years, it is estimated that the prevalence of sleep-disordered breathing is 9% in women and 24% in men, on the basis of more than five AHI events per hour of sleep. Among the women with sleep disorder breathing, 22.6% had daytime sleepiness and among the men, 15.5% had daytime sleepiness. Based on this, the prevalence of OSA in the middle-aged adult population is estimated to be 2% in women and 4% in men.
Snoring is present in 94% of OSA patients, but not all snorers have OSA. Women report daytime sleepiness less often compared with their male counterparts (of similar age, body mass index [BMI], and AHI). Prevalence of OSA tends to be higher in older age groups compared with younger age groups.
Diagnostic Value of Polysomnography
It is believed that PSG in the sleep laboratory is more accurate than in-home PSG. In the absence of a gold standard, however, claims of accuracy cannot be substantiated. In general, there is poor correlation between PSG variables and clinical variables. A variety of cut-off points of AHI (> 5, > 10, and > 15) are arbitrarily used to diagnose and categorize severity of OSA, though the clinical importance of these cut-off points has not been determined.
Recently, a study of the use of a therapeutic trial of CPAP to diagnose OSA was reported. The authors studied habitual snorers with daytime sleepiness in the absence of other medical or psychiatric disorders. Using PSG as the reference standard, the authors calculated the sensitivity of this test to be 80% and its specificity to be 97%. Further, they concluded that PSG could be avoided in 46% of this population.
Obstructive Sleep Apnea and Obesity
Obstructive sleep apnea is strongly associated with obesity. Obese individuals (BMI >30 kg/m2) are at higher risk for OSA compared with non-obese individuals and up to 75% of OSA patients are obese. It is hypothesized that obese individuals have large deposits of fat in the neck that cause the upper airway to collapse in the supine position during sleep. The observations reported from several studies support the hypothesis that AHIs (or RDIs) are significantly reduced with weight loss in obese individuals.
Obstructive Sleep Apnea and Cardiovascular Diseases
Associations have been shown between OSA and comorbidities such as diabetes mellitus and hypertension, which are known risk factors for myocardial infarction and stroke. Patients with more severe forms of OSA (based on AHI) report poorer quality of life and increased health care utilization compared with patients with milder forms of OSA. From animal models, it is hypothesized that sleep fragmentation results in glucose intolerance and hypertension. There is, however, no evidence from prospective studies in humans to establish a causal link between OSA and hypertension or diabetes mellitus. It is also not clear that the associations between OSA and other diseases are independent of obesity; in most of these studies, patients with higher values of AHI had higher values of BMI compared with patients with lower AHI values.
A recent meta-analysis of bariatric surgery has shown that weight loss in obese individuals (mean BMI = 46.8 kg/m2; range = 32.30–68.80) significantly improved their health profile. Diabetes was resolved in 76.8% of patients, hypertension was resolved in 61.7% of patients, hyperlipidemia improved in 70% of patients, and OSA resolved in 85.7% of patients. This suggests that obesity leads to OSA, diabetes, and hypertension, rather than OSA independently causing diabetes and hypertension.
Health Technology Assessments, Guidelines, and Recommendations
In April 2005, the Centers for Medicare and Medicaid Services (CMS) in the United States published its decision and review regarding in-home and in-lab sleep studies for the diagnosis and treatment of OSA with CPAP. In order to cover CPAP, CMS requires that a diagnosis of OSA be established using PSG in a sleep laboratory. After reviewing the literature, CMS concluded that the evidence was not adequate to determine that unattended portable sleep study was reasonable and necessary in the diagnosis of OSA.
In May 2005, the Canadian Coordinating Office of Health Technology Assessment (CCOHTA) published a review of guidelines for referral of patients to sleep laboratories. The review included 37 guidelines and associated reviews that covered 18 applications of sleep laboratory studies. The CCOHTA reported that the level of evidence for many applications was of limited quality, that some cited studies were not relevant to the recommendations made, that many recommendations reflect consensus positions only, and that there was a need for more good quality studies of many sleep laboratory applications.
As of the time of writing, there are 97 licensed sleep laboratories in Ontario. In 2000, the number of sleep studies performed in Ontario was 376/100,000 people. There was a steady rise in sleep studies in the following years such that in 2004, 769 sleep studies per 100,000 people were performed, for a total of 96,134 sleep studies. Based on prevalence estimates of the Wisconsin Sleep Cohort Study, it was estimated that 927,105 people aged 30 to 60 years have sleep-disordered breathing. Thus, there may be a 10-fold rise in the rate of sleep tests in the next few years.
Economic Analysis
In 2004, approximately 96,000 sleep studies were conducted in Ontario at a total cost of ~$47 million (Cdn). Since obesity is associated with sleep disordered breathing, MAS compared the costs of sleep studies to the cost of bariatric surgery. The cost of bariatric surgery is $17,350 per patient. In 2004, Ontario spent $4.7 million per year for 270 patients to undergo bariatric surgery in the province, and $8.2 million for 225 patients to seek out-of-country treatment. Using a Markov model, it was concluded that shifting costs from sleep studies to bariatric surgery would benefit more patients with OSA and may also prevent health consequences related to diabetes, hypertension, and hyperlipidemia. It is estimated that the annual cost of treating comorbid conditions in morbidly obese patients often exceeds $10,000 per patient. Thus, the downstream cost savings could be substantial.
Considerations for Policy Development
Weight loss is associated with a decrease in OSA severity. Treating and preventing obesity would also substantially reduce the economic burden associated with diabetes, hypertension, hyperlipidemia, and OSA. Promotion of healthy weights may be achieved by a multisectorial approach as recommended by the Chief Medical Officer of Health for Ontario. Bariatric surgery has the potential to help morbidly obese individuals (BMI > 35 kg/m2 with an accompanying comorbid condition, or BMI > 40 kg/m2) lose weight. In January 2005, MAS completed an assessment of bariatric surgery, based on which OHTAC recommended an improvement in access to these surgeries for morbidly obese patients in Ontario.
Habitual snorers with excessive daytime sleepiness have a high pretest probability of having OSA. These patients could be offered a therapeutic trial of CPAP to diagnose OSA, rather than a PSG. A majority of these patients are also obese and may benefit from weight loss. Individualized weight loss programs should, therefore, be offered and patients who are morbidly obese should be offered bariatric surgery.
That said, and in view of the still evolving understanding of the causes, consequences and optimal treatment of OSA, further research is warranted to identify which patients should be screened for OSA.
PMCID: PMC3379160  PMID: 23074483
21.  Effects of Maternal Obstructive Sleep Apnoea on Fetal Growth: A Prospective Cohort Study 
PLoS ONE  2013;8(7):e68057.
The objective of this study is to determine whether obstructive sleep apnea (OSA) is associated with reduced fetal growth, and whether nocturnal oxygen desaturation precipitates acute fetal heart rate changes.
Study Design
We performed a prospective observational study, screening 371 women in the second trimester for OSA symptoms. 41 subsequently underwent overnight sleep studies to diagnose OSA. Third trimester fetal growth was assessed using ultrasound. Fetal heart rate monitoring accompanied the sleep study. Cord blood was taken at delivery, to measure key regulators of fetal growth.
Of 371 women screened, 108 (29%) were high risk for OSA. 26 high risk and 15 low risk women completed the longitudinal study; 14 had confirmed OSA (cases), and 27 were controls. The median (interquartile range) respiratory disturbance index (number of apnoeas, hypopnoeas or respiratory related arousals/hour of sleep) was 7.9 (6.1–13.8) for cases and 2.2 (1.3–3.5) for controls (p<0.001). Impaired fetal growth was observed in 43% (6/14) of cases, vs 11% (3/27) of controls (RR 2.67; 1.25–5.7; p = 0.04). Using logistic regression, only OSA (OR 6; 1.2–29.7, p = 0.03) and body mass index (OR 2.52; 1.09–5.80, p = 0.03) were significantly associated with impaired fetal growth. After adjusting for body mass index on multivariate analysis, the association between OSA and impaired fetal growth was not appreciably altered (OR 5.3; 0.93–30.34, p = 0.06), although just failed to achieve statistical significance. Prolonged fetal heart rate decelerations accompanied nocturnal oxygen desaturation in one fetus, subsequently found to be severely growth restricted. Fetal growth regulators showed changes in the expected direction- with IGF-1 lower, and IGFBP-1 and IGFBP-2 higher- in the cord blood of infants of cases vs controls, although were not significantly different.
OSA may be associated with reduced fetal growth in late pregnancy. Further evaluation is warranted to establish whether OSA may be an important contributor to adverse perinatal outcome, including stillbirth.
PMCID: PMC3722214  PMID: 23894293
22.  Traditional birth attendant training for improving health behaviours and pregnancy outcomes 
Between the 1970s and 1990s, the World Health Organization promoted traditional birth attendant (TBA) training as one strategy to reduce maternal and neonatal mortality. To date, evidence in support of TBA training is limited but promising for some mortality outcomes.
To assess the effects of TBA training on health behaviours and pregnancy outcomes.
Search methods
We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (18 June 2012), citation alerts from our work and reference lists of studies identified in the search.
Selection criteria
Published and unpublished randomised controlled trials (RCT), comparing trained versus untrained TBAs, additionally trained versus trained TBAs, or women cared for/living in areas served by TBAs.
Data collection and analysis
Three authors independently assessed study quality and extracted data in the original and first update review. Three authors and one external reviewer independently assessed study quality and two extracted data in this second update.
Main results
Six studies involving over 1345 TBAs, more than 32,000 women and approximately 57,000 births that examined the effects of TBA training for trained versus untrained TBAs (one study) and additionally trained TBA training versus trained TBAs (five studies) are included in this review. These studies consist of individual randomised trials (two studies) and cluster-randomised trials (four studies). The primary outcomes across the sample of studies were perinatal deaths, stillbirths and neonatal deaths (early, late and overall).
Trained TBAs versus untrained TBAs: one cluster-randomised trial found a significantly lower perinatal death rate in the trained versus untrained TBA clusters (adjusted odds ratio (OR) 0.70, 95% confidence interval (CI) 0.59 to 0.83), lower stillbirth rate (adjusted OR 0.69, 95% CI 0.57 to 0.83) and lower neonatal death rate (adjusted OR 0.71, 95% CI 0.61 to 0.82). This study also found the maternal death rate was lower but not significant (adjusted OR 0.74, 95% CI 0.45 to 1.22).
Additionally trained TBAs versus trained TBAs: three large cluster-randomised trials compared TBAs who received additional training in initial steps of resuscitation, including bag-valve-mask ventilation, with TBAs who had received basic training in safe, clean delivery and immediate newborn care. Basic training included mouth-to-mouth resuscitation (two studies) or bag-valve-mask resuscitation (one study). There was no significant difference in the perinatal death rate between the intervention and control clusters (one study, adjusted OR 0.79, 95% CI 0.61 to 1.02) and no significant difference in late neonatal death rate between intervention and control clusters (one study, adjusted risk ratio (RR) 0.47, 95% CI 0.20 to 1.11). The neonatal death rate, however, was 45% lower in intervention compared with the control clusters (one study, 22.8% versus 40.2%, adjusted RR 0.54, 95% CI 0.32 to 0.92).
We conducted a meta-analysis on two outcomes: stillbirths and early neonatal death. There was no significant difference between the additionally trained TBAs versus trained TBAs for stillbirths (two studies, mean weighted adjusted RR 0.99, 95% CI 0.76 to 1.28) or early neonatal death rate (three studies, mean weighted adjusted RR 0.83, 95% CI 0.68 to 1.01).
Authors’ conclusions
The results are promising for some outcomes (perinatal death, stillbirth and neonatal death). However, most outcomes are reported in only one study. A lack of contrast in training in the intervention and control clusters may have contributed to the null result for stillbirths and an insufficient number of studies may have contributed to the failure to achieve significance for early neonatal deaths. Despite the additional studies included in this updated systematic review, there remains insufficient evidence to establish the potential of TBA training to improve peri-neonatal mortality.
PMCID: PMC4158424  PMID: 22895949
Health Behavior; Infant Mortality; Infant, Newborn; Maternal Mortality; Midwifery [*education; standards]; Perinatal Mortality; Pregnancy Outcome [*epidemiology]; Randomized Controlled Trials as Topic; Stillbirth [epidemiology]; Female; Humans; Pregnancy
23.  Intermittent Preventive Treatment of Malaria in Pregnancy with Mefloquine in HIV-Infected Women Receiving Cotrimoxazole Prophylaxis: A Multicenter Randomized Placebo-Controlled Trial 
PLoS Medicine  2014;11(9):e1001735.
Clara Menéndez and colleagues conducted a randomized controlled trial among HIV-positive pregnant women in Kenya, Mozambique, and Tanzania to investigate the safety and efficacy of mefloquine as intermittent preventative therapy for malaria in women receiving cotrimoxazole prophylaxis and long-lasting insecticide treated nets.
Please see later in the article for the Editors' Summary
Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended for malaria prevention in HIV-negative pregnant women, but it is contraindicated in HIV-infected women taking daily cotrimoxazole prophylaxis (CTXp) because of potential added risk of adverse effects associated with taking two antifolate drugs simultaneously. We studied the safety and efficacy of mefloquine (MQ) in women receiving CTXp and long-lasting insecticide treated nets (LLITNs).
Methods and Findings
A total of 1,071 HIV-infected women from Kenya, Mozambique, and Tanzania were randomized to receive either three doses of IPTp-MQ (15 mg/kg) or placebo given at least one month apart; all received CTXp and a LLITN. IPTp-MQ was associated with reduced rates of maternal parasitemia (risk ratio [RR], 0.47 [95% CI 0.27–0.82]; p = 0.008), placental malaria (RR, 0.52 [95% CI 0.29–0.90]; p = 0.021), and reduced incidence of non-obstetric hospital admissions (RR, 0.59 [95% CI 0.37–0.95]; p = 0.031) in the intention to treat (ITT) analysis. There were no differences in the prevalence of adverse pregnancy outcomes between groups. Drug tolerability was poorer in the MQ group compared to the control group (29.6% referred dizziness and 23.9% vomiting after the first IPTp-MQ administration). HIV viral load at delivery was higher in the MQ group compared to the control group (p = 0.048) in the ATP analysis. The frequency of perinatal mother to child transmission of HIV was increased in women who received MQ (RR, 1.95 [95% CI 1.14–3.33]; p = 0.015). The main limitation of the latter finding relates to the exploratory nature of this part of the analysis.
An effective antimalarial added to CTXp and LLITNs in HIV-infected pregnant women can improve malaria prevention, as well as maternal health through reduction in hospital admissions. However, MQ was not well tolerated, limiting its potential for IPTp and indicating the need to find alternatives with better tolerability to reduce malaria in this particularly vulnerable group. MQ was associated with an increased risk of mother to child transmission of HIV, which warrants a better understanding of the pharmacological interactions between antimalarials and antiretroviral drugs.
Trial registration NCT 00811421; Pan African Clinical Trials Registry PACTR 2010020001813440
Please see later in the article for the Editors' Summary
Editors' Summary
Malaria, a mosquito-borne parasitic disease, kills about 600,000 people every year. Most of these deaths occur among young children living in sub-Saharan Africa but pregnant women living in Africa are also very vulnerable to malaria. Infection with malaria during pregnancy can cause severe maternal anemia (reduced red blood cell numbers), stillbirths, and pre-term and low-birthweight babies, and is responsible for the deaths of many African women and their babies. To reduce the loss of life from malaria in pregnancy, the World Health Organization (WHO) recommends that pregnant women living in Africa receive the antimalarial drug sulfadoxine-pyrimethamine (SP) at each scheduled antenatal care visit given at least a month apart (intermittent preventive treatment in pregnancy [IPTp]). In addition, WHO advises pregnant women to sleep under insecticide-treated bed nets to protect themselves from the bites of infected mosquitoes and recommends effective case management of pregnant women with malarial illness.
Why Was This Study Done?
Pregnant women living in Africa are often infected with HIV, the virus that causes AIDS. HIV infection increases both the risk and severity of malaria infection during pregnancy, and at least one million pregnancies are complicated by co-infection with malaria and HIV in sub-Saharan Africa every year. WHO recommends that HIV-positive pregnant women take cotrimoxazole (CTX) daily to prevent opportunistic infections (CTX prophylaxis [CTXp]). Unfortunately, both CTX and SP are antifolate drugs and taking two drugs of this type increases a woman's risk of developing a severe skin reaction. Moreover, although CTXp protects children and HIV-infected adults against malaria, it is not known whether CTXp alone protects HIV-infected pregnant women adequately against malaria. Thus, evaluations of alternative drugs for use in IPTp in HIV-positive pregnant women are needed. In this randomized placebo-controlled trial, the researchers study the safety and efficacy of the antimalarial drug mefloquine (MQ) in HIV-infected women receiving CTXp. A randomized, placebo-controlled trial compares outcomes among people chosen through the play of chance to receive either the drug under investigation or a “dummy” (placebo) drug.
What Did the Researchers Do and Find?
The researchers allocated 1,071 HIV-infected pregnant women from Kenya, Mozambique, and Tanzania to receive three doses of MQ (IPTp-MQ), given at least one month apart, or three doses of placebo. All the women received CTXp and were given an insecticide-treated bed net. In an intention-to-treat analysis (an analysis that considers the outcomes of all trial participants irrespective of whether they receive their allocated treatment), the prevalence of parasitemia (parasites in the blood) at delivery among women given IPTp-MQ was 3.5% whereas the prevalence among women given the placebo was 6.9%. In other words, compared to placebo, IPTp-MQ was associated with a reduced risk of maternal parasitemia. IPTp-MQ was also associated with a reduced rate of placental malaria (parasites in the placenta) and a reduced incidence of hospital admissions for non-pregnancy related causes. There was no difference in adverse pregnancy outcomes such as stillbirth between the intervention groups but drug tolerability was poorer in the MQ group than in the placebo group. Finally, in an exploratory (unplanned) according-to-protocol analysis (an analysis that only considers outcomes in trial participants who receive their allocated intervention), women in the MQ group had a higher HIV viral load at delivery than women in the control group and were nearly twice as likely to transmit HIV to their child around the time of birth.
What Do These Findings Mean?
These findings suggest that the addition of IPTp-MQ to CTXp and the use of insecticide-treated bed nets can improve malaria prevention and maternal health in HIV-infected pregnant women in Africa. However, the poor tolerability of MQ and the association of MQ treatment with both an increased HIV viral load at delivery and a higher frequency of mother-to-child-transmission of HIV when compared to placebo raise concerns about the use of MQ in IPTp. Because these last two findings came from an exploratory analysis, which is more likely to throw up a chance finding than a pre-planned analysis further studies are needed to confirm these unexpected but potentially important findings. Nevertheless, overall, the findings of this study suggest that MQ should not be recommended for IPTp in HIV-infected pregnant women in Africa and highlight the need to find alternative drugs for malaria prevention in this group of women who are particularly vulnerable to malaria.
Additional Information
Please access these websites via the online version of this summary at
This study is further discussed in a PLOS Medicine Perspective by Richard Steketee.
A related PLOS Medicine Research Article by González et al. compares the efficacy of IPTp-MQ and IPTp-SP in HIV-negative women
Information is available from the World Health Organization on malaria (in several languages) and on malaria in pregnancy; information on IPTp and the current WHO policy recommendation on IPTp with SP are available; the 2013 World Malaria Report provides details of the current global malaria situation
The US Centers for Disease Control and Prevention also provides information on malaria; a personal story about malaria in pregnancy is available
Information is available from the Roll Back Malaria Partnership on all aspects of global malaria control, including information on malaria in pregnancy
The Malaria in Pregnancy Consortium is undertaking research into the prevention and treatment of malaria in pregnancy
MedlinePlus provides links to additional information on malaria (in English and Spanish)
More information about the trial protocol is available
PMCID: PMC4172537  PMID: 25247995
24.  Reducing stillbirths: prevention and management of medical disorders and infections during pregnancy 
BMC Pregnancy and Childbirth  2009;9(Suppl 1):S4.
An estimated two-thirds of the world's 3.2 million stillbirths occur antenatally, prior to labour, and are often overlooked in policy and programs. Poorly recognised, untreated or inadequately treated maternal infections such as syphilis and malaria, and maternal conditions including hypertensive disorders, are known risk factors for stillbirth.
We undertook a systematic review of the evidence for 16 antenatal interventions with the potential to prevent stillbirths. We searched a range of sources including PubMed and the Cochrane Library. For interventions with prior Cochrane reviews, we conducted additional meta-analyses including eligible newer randomised controlled trials following the Cochrane protocol. We focused on interventions deliverable at the community level in low-/middle-income countries, where the burden of stillbirths is greatest.
Few of the studies we included reported stillbirth as an outcome; most that did were underpowered to assess this outcome. While Cochrane reviews or meta-analyses were available for many interventions, few focused on stillbirth or perinatal mortality as outcomes, and evidence was frequently conflicting. Several interventions showed clear evidence of impact on stillbirths, including heparin therapy for certain maternal indications; syphilis screening and treatment; and insecticide-treated bed nets for prevention of malaria. Other interventions, such as management of obstetric intrahepatic cholestasis, maternal anti-helminthic treatment, and intermittent preventive treatment of malaria, showed promising impact on stillbirth rates but require confirmatory studies. Several interventions reduced known risk factors for stillbirth (e.g., anti-hypertensive drugs for chronic hypertension), yet failed to show statistically significant impact on stillbirth or perinatal mortality rates. Periodontal disease emerged as a clear risk factor for stillbirth but no interventions have reduced stillbirth rates.
Evidence for some newly recognised risk factors for stillbirth, including periodontal disease, suggests the need for large, appropriately designed randomised trials to test whether intervention can minimise these risks and prevent stillbirths. Existing evidence strongly supports infection control measures, including syphilis screening and treatment and malaria prophylaxis in endemic areas, for preventing antepartum stillbirths. These interventions should be incorporated into antenatal care programs based on attributable risks and burden of disease.
PMCID: PMC2679410  PMID: 19426467
25.  Relation of Trihalomethane Concentrations in Public Water Supplies to Stillbirth and Birth Weight in Three Water Regions in England 
Environmental Health Perspectives  2004;113(2):225-232.
We investigated the association between total trihalomethanes (TTHMs) and risk of stillbirth and low and very low birth weight in three water regions in England, 1992–1998; associations with individual trihalomethanes (THMs) were also examined. Modeled estimates of quarterly TTHM concentrations in water zones, categorized as low (< 30 μg/L), medium (30–59 μg/L), or high (≥60 μg/L), were linked to approximately 1 million routine birth and stillbirth records using maternal residence at time of birth. In one region, where there was a positive socioeconomic deprivation gradient across exposure categories, there was also a positive, significant association of TTHM with risk of stillbirth and low and very low birth weight. Overall summary estimates across the three regions using a random-effects model to allow for between-region heterogeneity in exposure effects showed small excess risks in areas with high TTHM concentrations for stillbirths [odds ratio (OR) = 1.11; 95% confidence interval (CI), 1.00–1.23), low birth weight (OR = 1.09; 95% CI, 0.93–1.27), and very low birth weight (OR = 1.05; 95% CI, 0.82–1.34). Among the individual THMs, chloroform showed a similar pattern of risk as TTHM, but no association was found with concentrations of bromodichloromethane or total brominated THMs. Our findings overall suggest a significant association of stillbirths with maternal residence in areas with high TTHM exposure. Further work is needed looking at cause-specific stillbirths and effects of other disinfection by-products and to help differentiate between alternative (noncausal) explanations and those that may derive from the water supply.
PMCID: PMC1277869  PMID: 15687062
chemical; disinfection; infant low birth weight; pregnancy outcome; stillbirth; trihalomethanes; water pollution; water purification

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