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1.  Association between Prenatal Exposure to Antiretroviral Therapy and Birth Defects: An Analysis of the French Perinatal Cohort Study (ANRS CO1/CO11) 
PLoS Medicine  2014;11(4):e1001635.
Jeanne Sibiude and colleagues use the French Perinatal Cohort to estimate the prevalence of birth defects in children born to HIV-infected women receiving antiretroviral therapy during pregnancy.
Please see later in the article for the Editors' Summary
Background
Antiretroviral therapy (ART) has major benefits during pregnancy, both for maternal health and to prevent mother-to-child transmission of HIV. Safety issues, including teratogenic risk, need to be evaluated. We estimated the prevalence of birth defects in children born to HIV-infected women receiving ART during pregnancy, and assessed the independent association of birth defects with each antiretroviral (ARV) drug used.
Methods and Findings
The French Perinatal Cohort prospectively enrolls HIV-infected women delivering in 90 centers throughout France. Children are followed by pediatricians until 2 y of age according to national guidelines.
We included 13,124 live births between 1994 and 2010, among which, 42% (n = 5,388) were exposed to ART in the first trimester of pregnancy. Birth defects were studied using both European Surveillance of Congenital Anomalies (EUROCAT) and Metropolitan Atlanta Congenital Defects Program (MACDP) classifications; associations with ART were evaluated using univariate and multivariate logistic regressions. Correction for multiple comparisons was not performed because the analyses were based on hypotheses emanating from previous findings in the literature and the robustness of the findings of the current study. The prevalence of birth defects was 4.4% (95% CI 4.0%–4.7%), according to the EUROCAT classification. In multivariate analysis adjusting for other ARV drugs, maternal age, geographical origin, intravenous drug use, and type of maternity center, a significant association was found between exposure to zidovudine in the first trimester and congenital heart defects: 2.3% (74/3,267), adjusted odds ratio (AOR) = 2.2 (95% CI 1.3–3.7), p = 0.003, absolute risk difference attributed to zidovudine +1.2% (95% CI +0.5; +1.9%). Didanosine and indinavir were associated with head and neck defects, respectively: 0.5%, AOR = 3.4 (95% CI 1.1–10.4), p = 0.04; 0.9%, AOR = 3.8 (95% CI 1.1–13.8), p = 0.04. We found a significant association between efavirenz and neurological defects (n = 4) using the MACDP classification: AOR = 3.0 (95% CI 1.1–8.5), p = 0.04, absolute risk +0.7% (95% CI +0.07%; +1.3%). But the association was not significant using the less inclusive EUROCAT classification: AOR = 2.1 (95% CI 0.7–5.9), p = 0.16. No association was found between birth defects and lopinavir or ritonavir with a power >85% for an odds ratio of 1.5, nor for nevirapine, tenofovir, stavudine, or abacavir with a power >70%. Limitations of the present study were the absence of data on termination of pregnancy, stillbirths, tobacco and alcohol intake, and concomitant medication.
Conclusions
We found a specific association between in utero exposure to zidovudine and heart defects; the mechanisms need to be elucidated. The association between efavirenz and neurological defects must be interpreted with caution. For the other drugs not associated with birth defects, the results were reassuring. Finally, whatever the impact that some ARV drugs may have on birth defects, it is surpassed by the major role of ART in the successful prevention of mother-to-child transmission of HIV.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
AIDS and HIV infection are commonly treated with antiretroviral therapy (ART), a combination of individual drugs that work together to prevent the replication of the virus and further spread of the infection. Starting in the 1990s, studies have shown that ART of HIV-infected women can substantially reduce transmission of the virus to the child during pregnancy and birth. Based on these results, ART was subsequently recommended for pregnant women. Since 2004, ART has been standard therapy for pregnant women with HIV/AIDS in high-income countries, and it is now recommended for all HIV-infected women worldwide. Several different antiviral drug combinations have been shown to be effective and are used to prevent mother-to-infant transmission. However, as with any other drugs taken during pregnancy, there is concern that ART can harm the developing fetus.
Why Was This Study Done?
Several previous studies have assessed the risk that ART taken by a pregnant woman might pose to her developing fetus, but the results have been inconsistent. Animal studies suggested an elevated risk for some drugs but not others. While some clinical studies have reported increases in birth defects in children born to mothers on ART, others have shown no such increase.
The discrepancy may be due to differences between the populations included in the studies and the different methods used to diagnose birth defects. Additional large studies are therefore necessary to obtain more and better evidence on the potential harm of individual anti-HIV drugs to children exposed during pregnancy. So in this study, the authors conducted a large cohort study in France to assess the relationship between different antiretroviral drugs and specific birth defects.
What Did the Researchers Do and Find?
The researchers used a large national health database known as the French Perinatal Cohort that contains information on HIV-infected mothers who delivered infants in 90 centers throughout France. Pediatricians follow all children, whatever their HIV status, to two years of age, and health statistics are collected according to national health-care guidelines. Analyzing the records, the researchers estimated the rate at which birth defects occurred in children exposed to antiretroviral drugs during pregnancy.
The researchers included 13,124 children who were born alive between 1994 and 2010 and had been exposed to ART during pregnancy. Children exposed in the first trimester of pregnancy, and those exposed during the second or third trimester, were compared to a control group (children not exposed to the drug during the whole pregnancy). Using two birth defect classification systems (EUROCAT and MACDP—MACDP collects more details on disease classification than EUROCAT), the researchers sought to detect a link between the occurrence of birth defects and exposure to individual antiretroviral drugs.
They found a small increase in the risk for heart defects in children with exposure to zidovudine. They also found an association between efavirenz exposure and a small increase in neurological defects, but only when using the MACDP classification system. The authors found no association between other antiretroviral drugs, including nevirapine (acting similar to efavirenz); tenofovir, stavudine, and abacavir (all three acting similar to zidovudine); and lopinavir and ritonavir (proteinase inhibitors) and any type of birth defect.
What Do These Findings Mean?
These findings show that, overall, the risks of birth defects in children exposed to antiretroviral drugs in utero are small when considering the clear benefit of preventing mother-to-child transmission of HIV. However, where there are safe and effective alternatives, it might be appropriate to avoid use by pregnant women of those drugs that are associated with elevated risks of birth defects.
Worldwide, a large number of children are exposed to zidovudine in utero, and these results suggest (though cannot prove) that these children may be at a slightly higher risk of heart defects. Current World Health Organization (WHO) guidelines for the prevention of mother-to-child transmission no longer recommend zidovudine for first-line therapy.
The implications of the higher rate of neurological birth defects observed in infants exposed to efavirenz in the first trimester are less clear. The EUROCAT classification excludes minor neurological abnormalities without serious medical consequences, and so the WHO guidelines that stress the importance of careful clinical follow-up of children with exposure to efavirenz seem adequate, based on the findings of this study. The study is limited by the lack of data on the use of additional medication and alcohol and tobacco use, which could have a direct impact on fetal development, and by the absence of data on birth defects and antiretroviral drug exposure from low-income countries. However, the findings of this study overall are reassuring and suggest that apart from zidovudine and possibly efavirenz, other antiretroviral drugs are not associated with birth defects, and their use during pregnancy does not pose a risk to the infant.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001635.
This study is further discussed in a PLOS Medicine Perspective by Mofenson and Watts
The World Health Organization has a webpage on mother-to-child transmission of HIV
The US National Institutes of Health provides links to additional information on mother-to-child transmission of HIV
The Elizabeth Glaser Pediatric AIDS Foundation also has a webpage on mother-to-child transmission
The French Perinatal Cohort has a webpage describing the cohort and its main publications (in French, with a summary in English)
doi:10.1371/journal.pmed.1001635
PMCID: PMC4004551  PMID: 24781315
2.  Maternal age and birth defects after the use of assisted reproductive technology in Japan, 2004–2010 
Background
Older mothers are becoming more common in Japan. One reason for this is the widespread use of assisted reproductive technology (ART). This study assesses the relationship between maternal age and the risk of birth defects after ART.
Methods
Nationwide data on ART between 2004 and 2010 in Japan were analyzed. Diseases that were classified as code Q00-Q99 (ie, congenital malformations, deformations, and chromosomal abnormalities) in the International Classification of Diseases, tenth edition, were selected. There were 219,185 pregnancies and 153,791 live births in total ART. Of these, 1943 abortions, stillbirths, or live births with birth defects were recorded. Percentage of multiple birth defects in total birth defects, the prevalence, crude relative risk and 95% confidence interval per 10,000 pregnancies and per 10,000 live births were analyzed according to the maternal age class (ie, 25–29, 30–34 (reference), 35–39, and 40+ years).
Results
Multiple birth defects were observed among 14% of the 25–29 year old class, and 8% among other classes when chromosomal abnormalities were excluded. The prevalence of chromosomal abnormalities per pregnancy and per live birth became significantly and rapidly higher in mothers in the age classes of 30–35 and 40+ years. Nonchromosomal birth defects per pregnancy decreased linearly with advanced maternal age, while the number of nonchromosomal birth defects per live birth formed a gradual U-shaped distribution. The prevalence per pregnancy of congenital malformations of the nervous system was significantly lower with advanced maternal age. The relative risk per live birth was significant regarding congenital malformations of the circulatory system for a maternal age of 40+ years. Some other significant associations between maternal age and birth defects were observed.
Conclusion
Maternal age is associated with several birth defects; however, older maternal age in itself does not produce noticeable extra risk for nonchromosomal birth defects overall.
doi:10.2147/IJWH.S32296
PMCID: PMC3581291  PMID: 23450007
birth defects; assisted reproductive technology; maternal age; pregnancy; live births; epidemiologic prevalence study
3.  Birth defects, season of conception, and sex of children born to pesticide applicators living in the Red River Valley of Minnesota, USA. 
Environmental Health Perspectives  2002;110(Suppl 3):441-449.
We previously demonstrated that the frequency of birth defects among children of residents of the Red River Valley (RRV), Minnesota, USA, was significantly higher than in other major agricultural regions of the state during the years 1989-1991, with children born to male pesticide applicators having the highest risk. The present, smaller cross-sectional study of 695 families and 1,532 children, conducted during 1997-1998, provides a more detailed examination of reproductive health outcomes in farm families ascertained from parent-reported birth defects. In the present study, in the first year of life, the birth defect rate was 31.3 births per 1,000, with 83% of the total reported birth defects confirmed by medical records. Inclusion of children identified with birth or developmental disorders within the first 3 years of life and later led to a rate of 47.0 per 1,000 (72 children from 1,532 live births). Conceptions in spring resulted in significantly more children with birth defects than found in any other season (7.6 vs. 3.7%). Twelve families had more than one child with a birth defect (n = 28 children). Forty-two percent of the children from families with recurrent birth defects were conceived in spring, a significantly higher rate than that for any other season. Three families in the kinships defined contributed a first-degree relative other than a sibling with the same or similar birth defect, consistent with a Mendelian inheritance pattern. The remaining nine families did not follow a Mendelian inheritance pattern. The sex ratio of children with birth defects born to applicator families shows a male predominance (1.75 to 1) across specific pesticide class use and exposure categories exclusive of fungicides. In the fungicide exposure category, normal female births significantly exceed male births (1.25 to 1). Similarly, the proportion of male to female children with birth defects is significantly lower (0.57 to 1; p = 0.02). Adverse neurologic and neurobehavioral developmental effects clustered among the children born to applicators of the fumigant phosphine (odds ratio [OR] = 2.48; confidence interval [CI], 1.2-5.1). Use of the herbicide glyphosate yielded an OR of 3.6 (CI, 1.3-9.6) in the neurobehavioral category. Finally, these studies point out that (a) herbicides applied in the spring may be a factor in the birth defects observed and (b) fungicides can be a significant factor in the determination of sex of the children of the families of the RRV. Thus, two distinct classes of pesticides seem to have adverse effects on different reproductive outcomes. Biologically based confirmatory studies are needed.
PMCID: PMC1241196  PMID: 12060842
4.  Congenital malformations in Ecuadorian children: urgent need to create a National Registry of Birth Defects 
Aim
This study sets out (a) to estimate the prevalence of admissions by birth defects, using the official database of hospitals of Ecuador; and (b) to set the basis for a new National Register of Birth Defects in Ecuador that works as a program for the clinical and epidemiological investigation of risk factors in the etiology of congenital anomalies in Ecuadorian hospitals, using a case-control methodological approach. This is the first report in their class.
Methods
The data used in this study are derived from the National Register of Hospital Admission/Discharges of the Instituto Nacional de Estadísticas y Censos; data of the Ministry of Public Health were also used. Ecuador does not have an official Medical Birth Registry or a Congenital Malformations Registry.
Results
A total of 51,375 discharges by congenital malformations were registered in a 7-year period. Of these, 16,679 admissions were of children aged less than 1 year of age, with a birth prevalence rate (BPR) of 72.33/10,000 births. 77% of the congenital defects registered comprise the 50 most common birth defects observed in this age group. Cleft lip was the most prevalent birth defect in children less than 1 year of age and the second most common defect in children 1 to 5 years of age. Unilateral cleft lip shows a BPR of 4.57/10,000 births; cardiac birth defects as a group have a BPR of 4.2; hydrocephalus a BPR of 3.77; and Down’s syndrome a BPR of 3.70. Undescended testicle was the most prevalent birth defect in children between 1 to 5 years. 9384 children under 1 year of age were male (55.9%) and 7053 were female (42.1%). BPR in males was 40.45 and in females 30.40.
Conclusion
This report documents the prevalence estimates for birth defects reported in the hospital discharge data. These estimates are important to 1) plan for health-care and education needs of the Ecuadorian population, 2) identify increased occurrences of birth defects in specific geographic regions, 3) serve as a reference point for assessment of provincial surveillance systems, 4) evaluate national public health interventions, 5) compare Ecuador prevalence estimates with those of other countries, and 6) help determine the appropriate allocation of resources for basic and public health research. There is an urgent need to establish a National Registry of Birth Defects involving different sources of information such as prenatal medical records, birth records and medical records during the first year of life at an early stage, and surveys on cytogenetic prenatal diagnostic surveys and cytogenetics of therapeutic abortions.
PMCID: PMC3681162  PMID: 23776361
Ecuador; genetics; birth defects surveillance; database; prevalence; epidemiology; congenital malformations
5.  Risk of Adverse Pregnancy Outcomes among Women Practicing Poor Sanitation in Rural India: A Population-Based Prospective Cohort Study 
PLoS Medicine  2015;12(7):e1001851.
Background
The importance of maternal sanitation behaviour during pregnancy for birth outcomes remains unclear. Poor sanitation practices can promote infection and induce stress during pregnancy and may contribute to adverse pregnancy outcomes (APOs). We aimed to assess whether poor sanitation practices were associated with increased risk of APOs such as preterm birth and low birth weight in a population-based study in rural India.
Methods and Findings
A prospective cohort of pregnant women (n = 670) in their first trimester of pregnancy was enrolled and followed until birth. Socio-demographic, clinical, and anthropometric factors, along with access to toilets and sanitation practices, were recorded at enrolment (12th week of gestation). A trained community health volunteer conducted home visits to ensure retention in the study and learn about study outcomes during the course of pregnancy. Unadjusted odds ratios (ORs) and adjusted odds ratios (AORs) and 95% confidence intervals for APOs were estimated by logistic regression models. Of the 667 women who were retained at the end of the study, 58.2% practiced open defecation and 25.7% experienced APOs, including 130 (19.4%) preterm births, 95 (14.2%) births with low birth weight, 11 (1.7%) spontaneous abortions, and six (0.9%) stillbirths. Unadjusted ORs for APOs (OR: 2.53; 95% CI: 1.72–3.71), preterm birth (OR: 2.36; 95% CI: 1.54–3.62), and low birth weight (OR: 2.00; 95% CI: 1.24–3.23) were found to be significantly associated with open defecation practices. After adjustment for potential confounders such as maternal socio-demographic and clinical factors, open defecation was still significantly associated with increased odds of APOs (AOR: 2.38; 95% CI: 1.49–3.80) and preterm birth (AOR: 2.22; 95% CI: 1.29–3.79) but not low birth weight (AOR: 1.61; 95% CI: 0.94–2.73). The association between APOs and open defecation was independent of poverty and caste. Even though we accounted for several key confounding factors in our estimates, the possibility of residual confounding should not be ruled out. We did not identify specific exposure pathways that led to the outcomes.
Conclusions
This study provides the first evidence, to our knowledge, that poor sanitation is associated with a higher risk of APOs. Additional studies are required to elucidate the socio-behavioural and/or biological basis of this association so that appropriate targeted interventions might be designed to support improved birth outcomes in vulnerable populations. While it is intuitive to expect that caste and poverty are associated with poor sanitation practice driving APOs, and we cannot rule out additional confounders, our results demonstrate that the association of poor sanitation practices (open defecation) with these outcomes is independent of poverty. Our results support the need to assess the mechanisms, both biological and behavioural, by which limited access to improved sanitation leads to APOs.
Pinaki Panigrahi and colleagues examine the association between adverse pregnancy outcomes and sanitation practices in pregnant women in rural India.
Editors' Summary
Background
Pregnancy is usually a happy time for women and their families. But, for some women, pregnancy ends unhappily. Some women lose their baby during early pregnancy (spontaneous abortion or miscarriage) or during late pregnancy (stillbirth). Others have their baby earlier than expected (preterm birth) or have a baby with low birth weight, two outcomes that adversely affect the baby’s survival and long-term health. The burden of adverse pregnancy outcomes (low birth weight, preterm birth, stillbirth, and spontaneous abortion) is substantial across the world but is particularly high in resource-limited settings. More than 60% of all preterm births take place in Asia and sub-Saharan Africa, and in India alone nearly 13 million babies (47% of all births) had a low birth weight in 2010. Many risk factors for adverse pregnancy outcomes have been identified, including infection, diabetes, poor antenatal care, and other socio-economic factors, but a clear causal mechanism for adverse pregnancy outcomes has not been established.
Why Was This Study Done?
One potential risk factor for adverse pregnancy outcomes, particularly in resource-limited settings, is poor sanitation—the inadequate provision of facilities and services for the safe disposal of human urine and feces. The WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation estimates that, globally, 1.1 billion people defecate in the open, a practice that can expose individuals to contact with human feces containing infectious organisms and that can contaminate food and water. Poor sanitation might contribute to adverse pregnancy outcomes by promoting infection or by causing stress during pregnancy. Women might, for example, limit their intake of food and water to avoid having to use inadequate toilet facilities, thereby adversely affecting the health of their unborn child. Here, the researchers assess whether poor sanitation practices are associated with an increased risk of adverse pregnancy outcomes by undertaking a population-based prospective study in two rural areas of Odisha state, India. Odisha has a high infant death rate (57 deaths per 1,000 live births), only 18.2% of households have access to an improved latrine (a facility such as a flush toilet that hygienically prevents human contact with human excreta), and 75% of households practice open defecation.
What Did the Researchers Do and Find?
For their study, the researchers enrolled 670 women during the first trimester of their pregnancy. They recorded socio-demographic data (for example, age, level of education, and household assets), clinical data, weight and height, and toilet access and sanitation practices for each woman at enrollment and followed them through pregnancy until birth. Nearly two-thirds of the women practiced open defecation, and a quarter experienced an adverse pregnancy outcome, most commonly a preterm birth and/or having a baby with low birth weight. After adjustment for potential confounding factors (factors that might affect outcomes, such as socio-demographic characteristics), open defecation was significantly associated with adverse pregnancy outcomes (all four adverse outcomes considered together) and with preterm birth, but not with low birth weight (a significant association is one that is unlikely to have happened by chance). Specifically, the adjusted odds ratios (an indicator of the strength of association between an exposure and an outcome; an odds ratio of more than one indicates that an exposure increases the risk of an outcome) of adverse pregnancy outcomes and preterm birth among women practicing open defecation compared with women with access to a latrine were 2.38 and 2.22, respectively. Notably, these associations were independent of poverty, caste, and religion.
What Do These Findings Mean?
These findings indicate that, among women in Odisha, defecation in the open (poor sanitation) during pregnancy is associated with a higher risk of any adverse pregnancy outcome and of preterm birth than the use of a latrine. Counterintuitively, these findings also suggest that the association between open defecation and adverse pregnancy outcomes is not explained by poverty. Although the researchers adjusted for numerous confounding factors in their analysis, the women who defecated in the open may have shared some other unknown characteristic (residual confounding) that was actually responsible for their increased risk of an adverse pregnancy outcome. Further studies are now needed to determine the socio-behavioral and/or biological basis of the association between poor sanitation and adverse pregnancy outcomes. Appropriate public health interventions can then be designed to reduce the burden of adverse pregnancy outcomes among women living in settings where there is limited access to adequate sanitation.
Additional Information
This list of resources contains links that can be accessed when viewing the PDF on a device or via the online version of the article at http://dx.doi.org/10.1371/journal.pmed.1001828.
The March of Dimes, a non-profit organization for pregnancy and baby health, provides information on pregnancy loss, preterm birth, and low birth weight
Tommy’s, a UK non-profit organization that funds research into stillbirth, premature birth, and miscarriage, also provides information about adverse pregnancy outcomes
The World Health Organization (WHO) provides information on water, sanitation, and health (in several languages)
The WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation monitors progress toward improved global sanitation; its 2014 report on progress in water sanitation is available (in several languages)
The children’s charity UNICEF, which protects the rights of children and young people around the world, provides information on water, sanitation, and health (in several languages)
The Water Supply and Sanitation Collaborative Council and the non-governmental organization Practical Action provide information on approaches and technologies for improving sanitation
A PLOS Medicine Collection on water and sanitation and a Policy Forum by Velleman et al. on improving water, sanitation, and hygiene for maternal and newborn health are available
doi:10.1371/journal.pmed.1001851
PMCID: PMC4511257  PMID: 26151447
6.  In Vitro Fertilization and Multiple Pregnancies 
Executive Summary
Objective
The objective of this health technology policy assessment was to determine the clinical effectiveness and cost-effectiveness of IVF for infertility treatment, as well as the role of IVF in reducing the rate of multiple pregnancies.
Clinical Need: Target Population and Condition
Typically defined as a failure to conceive after a year of regular unprotected intercourse, infertility affects 8% to 16% of reproductive age couples. The condition can be caused by disruptions at various steps of the reproductive process. Major causes of infertility include abnormalities of sperm, tubal obstruction, endometriosis, ovulatory disorder, and idiopathic infertility. Depending on the cause and patient characteristics, management options range from pharmacologic treatment to more advanced techniques referred to as assisted reproductive technologies (ART). ART include IVF and IVF-related procedures such as intra-cytoplasmic sperm injection (ICSI) and, according to some definitions, intra-uterine insemination (IUI), also known as artificial insemination. Almost invariably, an initial step in ART is controlled ovarian stimulation (COS), which leads to a significantly higher rate of multiple pregnancies after ART compared with that following natural conception. Multiple pregnancies are associated with a broad range of negative consequences for both mother and fetuses. Maternal complications include increased risk of pregnancy-induced hypertension, pre-eclampsia, polyhydramnios, gestational diabetes, fetal malpresentation requiring Caesarean section, postpartum haemorrhage, and postpartum depression. Babies from multiple pregnancies are at a significantly higher risk of early death, prematurity, and low birth weight, as well as mental and physical disabilities related to prematurity. Increased maternal and fetal morbidity leads to higher perinatal and neonatal costs of multiple pregnancies, as well as subsequent lifelong costs due to disabilities and an increased need for medical and social support.
The Technology Being Reviewed
IVF was first developed as a method to overcome bilateral Fallopian tube obstruction. The procedure includes several steps: (1) the woman’s egg is retrieved from the ovaries; (2) exposed to sperm outside the body and fertilized; (3) the embryo(s) is cultured for 3 to 5 days; and (4) is transferred back to the uterus. IFV is considered to be one of the most effective treatments for infertility today. According to data from the Canadian Assisted Reproductive Technology Registry, the average live birth rate after IVF in Canada is around 30%, but there is considerable variation in the age of the mother and primary cause of infertility.
An important advantage of IVF is that it allows for the control of the number of embryos transferred. An elective single embryo transfer in IVF cycles adopted in many European countries was shown to significantly reduce the risk of multiple pregnancies while maintaining acceptable birth rates. However, when number of embryos transferred is not limited, the rate of IVF-associated multiple pregnancies is similar to that of other treatments involving ovarian stimulation. The practice of multiple embryo transfer in IVF is often the result of pressures to increase success rates due to the high costs of the procedure. The average rate of multiple pregnancies resulting from IVF in Canada is currently around 30%.
An alternative to IVF is IUI. In spite of reported lower success rates of IUI (pregnancy rates per cycle range from 8.7% to 17.1%) it is generally attempted before IVF due to its lower invasiveness and cost.
Two major drawbacks of IUI are that it cannot be used in cases of bilateral tubal obstruction and it does not allow much control over the risk of multiple pregnancies compared with IVF. The rate of multiple pregnancies after IUI with COS is estimated to be about 21% to 29%.
Ontario Health Insurance Plan Coverage
Currently, the Ontario Health Insurance Plan covers the cost of IVF for women with bilaterally blocked Fallopian tubes only, in which case it is funded for 3 cycles, excluding the cost of drugs. The cost of IUI is covered except for preparation of the sperm and drugs used for COS.
Diffusion of Technology
According to Canadian Assisted Reproductive Technology Registry data, in 2004 there were 25 infertility clinics across Canada offering IVF and 7,619 IVF cycles performed. In Ontario, there are 13 infertility clinics with about 4,300 IVF cycles performed annually.
Literature Review
Royal Commission Report on Reproductive Technologies
The 1993 release of the Royal Commission report on reproductive technologies, Proceed With Care, resulted in the withdrawal of most IVF funding in Ontario, where prior to 1994 IVF was fully funded. Recommendations of the Commission to withdraw IVF funding were largely based on findings of the systematic review of randomized controlled trials (RCTs) published before 1990. The review showed IVF effectiveness only in cases of bilateral tubal obstruction. As for nontubal causes of infertility, there was not enough evidence to establish whether IVF was effective or not.
Since the field of reproductive technology is constantly evolving, there have been several changes since the publication of the Royal Commission report. These changes include: increased success rates of IVF; introduction of ICSI in the early 1990’s as a treatment for male factor infertility; and improved embryo implantation rates allowing for the transfer of a single embryo to avoid multiple pregnancies after IVF.
Studies After the Royal Commission Report: Review Strategy
Three separate literature reviews were conducted in the following areas: clinical effectiveness of IVF, cost-effectiveness of IVF, and outcomes of single embryo transfer (SET) in IVF cycles.
Clinical effectiveness of IVF: RCTs or meta-analyses of RCTs that compared live birth rates after IVF versus alternative treatments, where the cause of infertility was clearly stated or it was possible to stratify the outcome by the cause of infertility.
Cost effectiveness of IVF: All relevant economic studies comparing IVF to alternative methods of treatment were reviewed
Outcomes of IVF with SET: RCTs or meta-analyses of RCTs that compared live birth rates and multiple birth rates associated with transfer of single versus double embryos.
OVID MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Library, the International Agency for Health Technology Assessment database, and websites of other health technology assessment agencies were searched using specific subject headings and keywords to identify relevant studies.
Summary of Findings
Comparative Clinical Effectiveness of IVF
Overall, there is a lack of well composed RCTs in this area and considerable diversity in both definition and measurement of outcomes exists between trials. Many studies used fertility or pregnancy rates instead of live birth rates. Moreover, the denominator for rate calculation varied from study to study (e.g. rates were calculated per cycle started, per cycle completed, per couple, etc...).
Nevertheless, few studies of sufficient quality were identified and categorized by the cause of infertility and existing alternatives to IVF. The following are the key findings:
A 2005 meta-analysis demonstrated that, in patients with idiopathic infertility, IVF was clearly superior to expectant management, but there were no statistically significant differences in live birth rates between IVF and IUI, nor between IVF and gamete-intra-Fallopian transfer.
A subset of data from a 2000 study showed no significant differences in pregnancy rates between IVF and IUI for moderate male factor infertility.
In patients with moderate male factor infertility, standard IVF was also compared with ICSI in a 2002 meta-analysis. All studies included in the meta-analysis showed superior fertilization rates with ICSI, and the pooled risk ratio for oocyte fertilization was 1.9 (95% Confidence Interval 1.4-2.5) in favour of ICSI. Two other RCTs in this area published after the 2002 meta-analysis had similar results and further confirmed these findings. There were no RCTs comparing IVF with ICSI in patients with severe male factor infertility, mainly because based on the expert opinion, ICSI might only be an effective treatment for severe male factor infertility.
Cost-Effectiveness of IVF
Five economic evaluations of IVF were found, including one comprehensive systematic review of 57 health economic studies. The studies compared cost-effectiveness of IVF with a number of alternatives such as observation, ovarian stimulation, IUI, tubal surgery, varicocelectomy, etc... The cost-effectiveness of IVF was analyzed separately for different types of infertility. Most of the reviewed studies concluded that due to the high cost, IVF has a less favourable cost-effectiveness profile compared with alternative treatment options. Therefore, IVF was not recommended as the first line of treatment in the majority of cases. The only two exceptions were bilateral tubal obstruction and severe male factor infertility, where an immediate offer of IVF/ICSI might the most cost-effective option.
Clinical Outcomes After Single Versus Double Embryo Transfer Strategies of IVF
Since the SET strategy has been more widely adopted in Europe, all RCT outcomes of SET were conducted in European countries. The major study in this area was a large 2005 meta-analysis, followed by two other published RCTs.
All of these studies reached similar conclusions:
Although a single SET cycle results in lower birth rates than a single double embryo transfer (DET) cycle, the cumulative birth rate after 2 cycles of SET (fresh + frozen-thawed embryos) was comparable to the birth rate after a single DET cycle (~40%).
SET was associated with a significant reduction in multiple births compared with DET (0.8% vs. 33.1% respectively in the largest RCT).
Most trials on SET included women younger than 36 years old with a sufficient number of embryos available for transfer that allowed for selection of the top quality embryo(s). A 2006 RCT, however, compared SET and DET strategies in an unselected group of patients without restrictions on the woman’s age or embryo quality. This study demonstrated that SET could be applied to older women.
Estimate of the Target Population
Based on results of the literature review and consultations with experts, four categories of infertile patients who may benefit from increased access to IVF/ICSI were identified:
Patients with severe male factor infertility, where IVF should be offered in conjunction with ICSI;
Infertile women with serious medical contraindications to multiple pregnancy, who should be offered IVF-SET;
Infertile patients who want to avoid the risk of multiple pregnancy and thus opt for IVF-SET; and
Patients who failed treatment with IUI and wish to try IVF.
Since, however, the latter indication does not reflect any new advances in IVF technology that would alter existing policy, it was not considered in this analysis.
Economic Analysis
Economic Review: Cost–Effectiveness of SET Versus DET
Conclusions of published studies on cost-effectiveness of SET versus DET were not consistent. While some studies found that SET strategy is more cost-effective due to avoidance of multiple pregnancies, other studies either did not find any significant differences in cost per birth between SET and DET, or favoured DET as a more cost-effective option.
Ontario-Based Economic Analysis
An Ontario-based economic analysis compared cost per birth using three treatment strategies: IUI, IVF-SET, and IVF-DET. A decision-tree model assumed three cycles for each treatment option. Two separate models were considered; the first included only fresh cycles of IVF, while the second had a combination of fresh and frozen cycles. Even after accounting for cost-savings due to avoidance of multiple pregnancies (only short-term complications), IVF-SET was still associated with a highest cost per birth. The approximate budget impact to cover the first three indications for IVF listed above (severe male factor infertility, women with medical contraindications to multiple pregnancy, and couples who wish to avoid the risk of multiple pregnancy) is estimated at $9.8 to $12.8 million (Cdn). Coverage of only first two indications, namely, ICSI in patients with severe male factor infertility and infertile women with serious medical contraindications to multiple pregnancy, is estimated at $3.8 to $5.5 million Cdn.
Other Considerations
International data shows that both IVF utilization and the average number of embryos transferred in IVF cycles are influenced by IVF funding policy. The success of the SET strategy in European countries is largely due to the fact that IVF treatment is subsidized by governments.
Surveys of patients with infertility demonstrated that a significant proportion (~40%) of patients not only do not mind having multiple babies, but consider twins being an ideal outcome of infertility treatment.
A women’s age may impose some restrictions on the implementation of a SET strategy.
Conclusions and Recommendations
A review of published studies has demonstrated that IVF-SET is an effective treatment for infertility that avoids multiple pregnancies.
However, results of an Ontario-based economic analysis shows that cost savings associated with a reduction in multiple pregnancies after IVF-SET does not justify the cost of universal IVF-SET coverage by the province. Moreover, the province currently funds IUI, which has been shown to be as effective as IVF for certain types of infertility and is significantly less expensive.
In patients with severe male factor infertility, IVF in conjunction with ICSI may be the only effective treatment.
Thus, 2 indications where additional IVF access should be considered include:
IVF/ICSI for patients with severe male factor infertility
IVF-SET in infertile women with serious medical contraindications to multiple pregnancy
PMCID: PMC3379537  PMID: 23074488
7.  Predicting Live Birth, Preterm Delivery, and Low Birth Weight in Infants Born from In Vitro Fertilisation: A Prospective Study of 144,018 Treatment Cycles 
PLoS Medicine  2011;8(1):e1000386.
Using the HFEA database of all 144,018 live births in all IVF cycles in the UK between 2003 and 2007, Scott Nelson and Debbie Lawlor show that couple- and treatment-specific factors can be used to help predict successful outcome following IVF.
Background
The extent to which baseline couple characteristics affect the probability of live birth and adverse perinatal outcomes after assisted conception is unknown.
Methods and Findings
We utilised the Human Fertilisation and Embryology Authority database to examine the predictors of live birth in all in vitro fertilisation (IVF) cycles undertaken in the UK between 2003 and 2007 (n = 144,018). We examined the potential clinical utility of a validated model that pre-dated the introduction of intracytoplasmic sperm injection (ICSI) as compared to a novel model. For those treatment cycles that resulted in a live singleton birth (n = 24,226), we determined the associates of potential risk factors with preterm birth, low birth weight, and macrosomia. The overall rate of at least one live birth was 23.4 per 100 cycles (95% confidence interval [CI] 23.2–23.7). In multivariable models the odds of at least one live birth decreased with increasing maternal age, increasing duration of infertility, a greater number of previously unsuccessful IVF treatments, use of own oocytes, necessity for a second or third treatment cycle, or if it was not unexplained infertility. The association of own versus donor oocyte with reduced odds of live birth strengthened with increasing age of the mother. A previous IVF live birth increased the odds of future success (OR 1.58, 95% CI 1.46–1.71) more than that of a previous spontaneous live birth (OR 1.19, 95% CI 0.99–1.24); p-value for difference in estimate <0.001. Use of ICSI increased the odds of live birth, and male causes of infertility were associated with reduced odds of live birth only in couples who had not received ICSI. Prediction of live birth was feasible with moderate discrimination and excellent calibration; calibration was markedly improved in the novel compared to the established model. Preterm birth and low birth weight were increased if oocyte donation was required and ICSI was not used. Risk of macrosomia increased with advancing maternal age and a history of previous live births. Infertility due to cervical problems was associated with increased odds of all three outcomes—preterm birth, low birth weight, and macrosomia.
Conclusions
Pending external validation, our results show that couple- and treatment-specific factors can be used to provide infertile couples with an accurate assessment of whether they have low or high risk of a successful outcome following IVF.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Worldwide, more than 10% of couples are infertile. Sometimes there is no obvious reason for a couple's inability to have children but, for many couples, problems with their eggs or sperm prevent “fertilization”—the union of an egg and a sperm that leads, eventually, to the birth of a baby. Until recently, little could be done to help infertile couples. Then, on the 25 July 1978, the world's first “test-tube baby” was born. Since then, 4 million babies have been born through in vitro fertilization (IVF). In IVF, mature eggs are collected from the woman (or from an egg donor if the woman cannot make her own eggs) after a course of special hormones, and they are mixed in a dish with her partner's sperm. If her partner has a low sperm count or abnormal sperm, a single sperm can be injected directly into the egg in a procedure called intracytoplasmic sperm injection (ICSI), which became widely available in the mid 1990s, or sperm from a donor can be used. Finally, a number (depending on the country) of embryos (eggs that have begun to divide and develop) are put back into the woman where, hopefully, they will establish a successful pregnancy.
Why Was This Study Done?
Not every attempt at IVF is successful. In the US and the UK, IVF is successful in about a third of women under 35 years old but in only 5%–10% of women over the age of 40. It would be useful to have a way to predict the likelihood of a live birth after IVF for individual couples. Such a “prediction model” would facilitate patient counseling, clinical decision making, and the allocation of IVF resources. In this study, the researchers use information on IVF cycles collected by the Human Fertilisation and Embryology Authority (HFEA), which regulates IVF in the UK, to assess the extent to which the characteristics of infertile couples and the treatment they receive can be used to predict live birth after IVF. They also use these data to identify which factors are associated with preterm delivery, low birthweight, and macrosomia (the birth of an unusually large baby), three undesirable birth characteristics.
What Did the Researchers Do and Find?
Between 2003 and 2007, 163,425 IVF cycles were completed in the UK, 23.4% of which resulted in at least one live birth. The researchers used the data collected by the HFEA on 144,018 of these cycles (the other cycles had missing data) to develop a multivariable logistic regression prediction model (a type of statistical model) for the outcome of IVF. According to this model, a decreased chance of at least one live birth was associated with several factors including increasing maternal age, increasing duration of infertility, and the use of the woman's own oocytes. By contrast, a previous IVF live birth and the use of ICSI were associated with increased chances of success. Importantly, compared with an established multivariable prediction model, which was developed before the introduction of ICSI, the researchers' new prediction model predicted the chance of a live birth following IVF with greater accuracy. Finally, the researchers report that the chances of preterm and low birthweight after IVF were increased if donor eggs were required and ICSI was not used, that an increased risk of macrosomia was associated with increasing maternal age and with a history of previous live births, and that all three undesirable birth characteristics were associated with infertility due to cervical problems.
What Do These Findings Mean?
These findings indicate that couple- and treatment-specific factors can be used to provide infertile couples with an accurate assessment of whether they have a low or high chance of a successful outcome following IVF. The prediction model developed here provides a more accurate assessment of likely outcomes after IVF than a previously established model. Furthermore, because the new model considers the effect of ICSI on outcomes, it should be more useful in contemporary populations than the established model, which does not consider ICSI. However, before this new prediction model is used to guide clinical decisions and to counsel patients, it needs to be validated using independent IVF data. To facilitate the external validation of their model, the researchers are currently generating a free web-based prediction tool and iPhone application (IVFpredict).
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000386.
The Human Fertilisation and Embryology Authority provides information on IVF and IVF statistics for the UK
The UK National Health Service Choices website provides information for patients on infertility and on IVF
The American Pregnancy Association has information for patients on infertility and on IVF
MedlinePlus has links to further resources on infertility and IVF (in English and Spanish)
The history of the development of IVF is described on the Nobel Prize website
The prediction tool that was used in this study is at http://www.IVFpredict.com
doi:10.1371/journal.pmed.1000386
PMCID: PMC3014925  PMID: 21245905
8.  The Association of Maternal Lifestyle with Birth Defects in Shaanxi Province, Northwest China 
PLoS ONE  2015;10(9):e0139452.
Background
The main objective was to investigate the burden of birth defects among alive infants and explore the impact of maternal lifestyle during pregnancy on the burden of birth defects in Northwest China.
Methods
A stratified multi-stage sampling method was used to study infants born during 2010–2013 (and their mothers) in Shaanxi province of Northwest China. Socio-demographic information was collected using a structured questionnaire, and medical records from the local hospitals were used to determine the final diagnosis of birth defects. Poisson regression analysis was performed to assess the association between maternal lifestyles during pregnancy and the burden of birth defects, while adjusting for potential confounders.
Results
We sampled 29098 infants, of whom 629 (i.e. 216.17 per 10000) were observed to have congenital defects. Cardiovascular system defects (77.32 per 10000) were found to be the most common. Mothers who had ever consumed alcohol during pregnancy were found to have infants with a higher prevalence of some categories of birth defects, including nervous system (Prevalence Rate Ratio, PRR:14.67, 95%CI:1.94, 110.92), cardiovascular system (PRR:3.22, 95%CI: 1.02, 10.16) and oral clefts (PRR:9.02, 95%CI: 2.08, 39.10) in contrast to infants of mothers without any alcohol consumption. Maternal passive smoking during pregnancy lead to the increased burden of malformations of eye, ear, face and neck (PRR:1.95, 95%CI:1.15, 3.33), cardiovascular system (PRR:1.70, 95%CI: 1.25, 2.31) and respiratory system (PRR:9.94, 95%CI: 2.37, 41.76) in their newborns. Further, tea or coffee consumption during pregnancy was positively correlated with the burden of specific birth defects, such as cardiovascular system (PRR: 2.44, 95%CI: 1.33, 4.46) and genital organs (PRR:14.72, 95%CI: 1.87, 116.11) among infants.
Conclusions
The prevalence of birth defects was high in Shaanxi province of Northwest China. The unhealthy lifestyles of mothers during pregnancy may increase the prevalence of congenital malformations. These findings in future may have some important implications for prevention of birth defects in Northwest China.
doi:10.1371/journal.pone.0139452
PMCID: PMC4589286  PMID: 26422609
9.  Prevalence of Esophageal Atresia among 18 International Birth Defects Surveillance Programs 
BACKGROUND
The prevalence of esophageal atresia (EA) has been shown to vary across different geographical settings. Investigation of geographical differences may provide an insight into the underlying etiology of EA.
METHODS
The study population comprised infants diagnosed with EA during 1998 to 2007 from 18 of the 46 birth defects surveillance programs, members of the International Clearinghouse for Birth Defects Surveillance and Research. Total prevalence per 10,000 births for EA was defined as the total number of cases in live births, stillbirths, and elective termination of pregnancy for fetal anomaly (ETOPFA) divided by the total number of all births in the population.
RESULTS
Among the participating programs, a total of 2943 cases of EA were diagnosed with an average prevalence of 2.44 (95% confidence interval [CI], 2.35–2.53) per 10,000 births, ranging between 1.77 and 3.68 per 10,000 births. Of all infants diagnosed with EA, 2761 (93.8%) were live births, 82 (2.8%) stillbirths, 89 (3.0%) ETOPFA, and 11 (0.4%) had unknown outcomes. The majority of cases (2020, 68.6%), had a reported EA with fistula, 749 (25.5%) were without fistula, and 174 (5.9%) were registered with an unspecified code.
CONCLUSIONS
On average, EA affected 1 in 4099 births (95% CI, 1 in 3954–4251 births) with prevalence varying across different geographical settings, but relatively consistent over time and comparable between surveillance programs. Findings suggest that differences in the prevalence observed among programs are likely to be attributable to variability in population ethnic compositions or issues in reporting or registration procedures of EA, rather than a real risk occurrence difference.
doi:10.1002/bdra.23067
PMCID: PMC4467200  PMID: 22945024
esophageal atresia; congenital anomalies; prevalence; epidemiology
10.  Increased prevalence of some birth defects in Korea, 2009–2010 
Background
Birth defects are a leading cause of neonatal and infant mortality, and several studies have indicated an increase in the prevalence of birth defects; more recent investigations have suggested that the trends of some defects are increasing in rapidly industrialized areas. This study estimates the prevalence rate and types of birth defects in Korea.
Methods
This study used medical insurance benefit data of 403,250 infants aged less than one year from the National Health Insurance Corporation from seven metropolitan areas in Korea for 2009 and 2010.
Results
The prevalence rate of birth defects was 548.3 per 10,000 births (95 % CI: 541.1–555.6), 306.8 among boys and 241.5 among girls. Anomalies of the circulatory system (particularly septal defects) were the most common (180.8 per 10,000), followed by defects of the genitourinary tract (130.1 per 10,000) (particularly obstructive genitourinary and undescended testis), musculoskeletal system (105.7 per 10,000), digestive system (24.7 per 10,000), and central nervous system (15.6 per 10,000).
Conclusions
Relatively higher rates of some birth defects were found in the metropolitan areas. The high differences of birth prevalences for septal heart defects and undescended testis are probably due in part to progress in clinical management and more frequent prenatal diagnosis. Environmental exposure might play a critical role in the development of some birth defects. In attempting to describe the prevalence and spatio-temporal variations of birth defects in Korea, establishment of a registry system of birth defects and environmental surveillance are needed.
doi:10.1186/s12884-016-0841-z
PMCID: PMC4802851  PMID: 27006092
Birth defects; Prevalence; Korea
11.  Long-term trends and seasonality of omphalocele during 1996–2010 in China: a retrospective analysis based on the hospital-based birth defects surveillance system 
Background
Little is known about secular trends and seasonal variation in the birth prevalence of omphalocele in China. This study aimed to explore the long-term trends and seasonality of this birth defect, to provide insight into the etiology and prevention of omphalocele.
Methods
A retrospective analysis of all births with omphalocele (1322 cases in 8.8 million births) registered in the hospital-based Chinese Birth Defects Monitoring Network between January 1996 and September 2010. Negative binomial cyclical regression models were used to analyze the long-term trends and seasonal fluctuations of omphalocele occurrence in the southern and northern regions and urban and rural areas of China.
Results
The total prevalence of omphalocele was 1.50 cases (95% confidence interval (CI): 1.42–1.58) per 10,000 births. There was no significant secular trend of omphalocele occurrence in China between 1996 and 2010. The observed prevalence of omphalocele in rural areas was 2.03–2.54 cases per 10,000 births between May and August, which was higher than that observed in other months. The highest prevalence of births with omphalocele in rural areas occurred at the end of June; on average, the prevalence of omphalocele at that time point increased by 20% (95% CI: 6–35%) compared with other months.
Conclusions
There were no long-term trends found for occurrence of omphalocele in China between 1996 and 2010; however, seasonality was observed for omphalocele in women living in rural areas. These results may help generate hypotheses for further study of environmental factors that vary by season.
doi:10.1186/s12884-015-0530-3
PMCID: PMC4456719  PMID: 25909955
Omphalocele; Birth prevalence, Secular trend, Seasonality; Negative binomial cyclical regression model
12.  Major Radiodiagnostic Imaging in Pregnancy and the Risk of Childhood Malignancy: A Population-Based Cohort Study in Ontario 
PLoS Medicine  2010;7(9):e1000337.
In a record-linkage study, Joel Ray and colleagues examine the association between diagnostic imaging during pregnancy and later childhood cancers.
Background
The association between fetal exposure to major radiodiagnostic testing in pregnancy—computed tomography (CT) and radionuclide imaging—and the risk of childhood cancer is not established.
Methods and Findings
We completed a population-based study of 1.8 million maternal-child pairs in the province of Ontario, from 1991 to 2008. We used Ontario's universal health care–linked administrative databases to identify all term obstetrical deliveries and newborn records, inpatient and outpatient major radiodiagnostic services, as well as all children with a malignancy after birth. There were 5,590 mothers exposed to major radiodiagnostic testing in pregnancy (3.0 per 1,000) and 1,829,927 mothers not exposed. The rate of radiodiagnostic testing increased from 1.1 to 6.3 per 1,000 pregnancies over the study period; about 73% of tests were CT scans. After a median duration of follow-up of 8.9 years, four childhood cancers arose in the exposed group (1.13 per 10,000 person-years) and 2,539 cancers in the unexposed group (1.56 per 10,000 person-years), a crude hazard ratio of 0.69 (95% confidence interval 0.26–1.82). After adjusting for maternal age, income quintile, urban status, and maternal cancer, as well as infant sex, chromosomal or congenital anomalies, and major radiodiagnostic test exposure after birth, the risk was essentially unchanged (hazard ratio 0.68, 95% confidence interval 0.25–1.80).
Conclusions
Although major radiodiagnostic testing is now performed in about 1 in 160 pregnancies in Ontario, the absolute annual risk of childhood malignancy following exposure in utero remains about 1 in 10,000. Since the upper confidence limit of the relative risk of malignancy may be as high as 1.8 times that of an unexposed pregnancy, we cannot exclude the possibility that fetal exposure to CT or radionuclide imaging is carcinogenic.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In industrialized countries, childhood cancer (any form of cancer in a child aged 14 years or under) remains a major cause of death. With the exception of a few known risk factors, such as acquired genetic predisposition to cancer, which accounts for about 10% of all childhood cancers, the etiology of most childhood cancer remains unknown. There is thought to be an association between exposure to ionizing radiation in pregnancy and the subsequent risk of development of cancer in the exposed mother's child, but the evidence base to support this association is conflicting. For example, studies examining maternal exposure to plain radiographs in pregnancy and subsequent childhood cancer are inconsistent. Furthermore, although their use has dramatically increased over the past two decades, little is known about the cancer risk related to certain types of radiodiagnostic tests, such as CT and radionuclide imaging, both of which expose the fetus to considerably higher doses of radiation than plain radiographs administered at the same anatomical level.
Why Was This Study Done?
Many women could be exposed to major radiodiagnostic tests, such as those used in emergency situations, before they are aware that they are pregnant, as almost 50% of pregnancies are unplanned. This situation means that it is important to determine the subsequent cancer risk to any child exposed to maternal radiodiagnostic tests before birth.
What Did the Researchers Do and Find?
The researchers conducted a retrospective population-based cohort study of women who delivered a live infant in Ontario, Canada between April 1, 1992 and March 31, 2008. The basis of the research was an anonymized database for the whole province of Ontario, where universal health care, including prenatal care and radiodiagnostic testing, is available to all residents. Database characteristics allowed the researchers to link maternal radiation exposure (a major radiodiagnostic test performed on the mother up to one day before her delivery date) in a specific (index) pregnancy to a subsequent malignancy in the child. After birth, maternal-infant pairs were only followed up if the infant was delivered at term, weighed 2,500 g or more, and survived for at least 30 days.
The researchers were able to follow up 1,835,517 maternal-child pairs. The overall rate of exposure to major radiodiagnostic testing in pregnancy was 3.0 per 1,000 and occurred at an estimated mean gestational age of 15.7 weeks. A total of four childhood cancers occurred in the exposed group and 2,539 cancers in the unexposed group corresponding to a crude hazard ratio of 0.69, which did not significantly change after adjustments were made for potential confounding factors, such as maternal age, sex, and the presence of any chromosomal or congenital anomalies in the infant. The overall prevalence of childhood cancer following exposure to CT or radionuclide imaging in pregnancy is under 0.07%, giving an incidence rate of 1.13 per 10,000 person-years.
What Do These Findings Mean?
These findings can help inform clinicians and mothers about the risk of childhood malignancy following major radiodiagnostic testing in pregnancy. The absolute risk appears to be low, while the relative risk is not materially higher than that of unexposed controls. However, as the upper confidence limit of the relative risk of malignancy may be a maximum of 1.8 times that of an unexposed pregnancy, the possibility that fetal exposure to CT or radionuclide imaging is carcinogenic cannot be excluded. Because this finding means that a very slight risk may exist, beta hCG testing should continue to be done in all potentially pregnant women before undergoing major radiodiagnostic testing, and lead apron shielding used in all women of reproductive age, whether or not known to be pregnant. In addition, nonradiation-emitting imaging, such as MRI and ultrasonography, should be considered first, when clinically appropriate. However, some pregnant women will still be faced with the decision to undergo CT or nuclear imaging because the test is clinically warranted. The findings of this study suggest that when clinically indicated, major radiodiagnostic testing in pregnancy should be performed, along with brief counseling to help lessen the anxiety experienced by an expectant mother before and after the birth of her child.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000337.
For information for patients and caregivers on radiodiagnostic testing, see The Royal College of Radiologists
The National Cancer Institute provides information about childhood cancer
CureSearch for Children's Cancer provides additional information about research into childhood cancer
doi:10.1371/journal.pmed.1000337
PMCID: PMC2935460  PMID: 20838660
13.  Prevalence and Correlates of Gastroschisis in 15 States, 1995 to 2005 
Obstetrics and gynecology  2013;122(2 0 1):275-281.
OBJECTIVE
To identify trends in the prevalence and epidemiologic correlates of gastroschisis using a large population-based sample with cases identified by the National Birth Defects Prevention Network over the course of an 11-year period.
METHODS
This study examined 4,713 cases of gastroschisis occurring in 15 states during 1995–2005, using public use natality data sets for denominators. Multivariable Poisson regression was used to identify statistically significant risk factors, and Joinpoint regression analyses were conducted to assess temporal trends in gastroschisis prevalence by maternal age and race and ethnicity.
RESULTS
Results show an increasing temporal trend for gastroschisis (from 2.32 per 10,000 to 4.42 per 10,000 live births). Increasing prevalence of gastroschisis has occurred primarily among younger mothers (11.45 per 10,000 live births among mothers younger than age 20 years compared with 5.35 per 10,000 among women aged 20 to 24 years). In the multivariable analysis, using non-Hispanic whites as the referent group, non-Hispanic black women had the lowest risk of having a gastroschisis-affected pregnancy (prevalence ratio 0.42, 95% confidence interval [CI] 0.37–0.48), followed by Hispanics (prevalence ratio 0.86, 95% CI 0.81–0.92). Gastroschisis prevalence did not differ by newborn sex.
CONCLUSIONS
Our findings demonstrate that the prevalence of gastroschisis has been increasing since 1995 among 15 states in the United States, and that higher rates of gastroschisis are associated with non-Hispanic white maternal race and ethnicity, and maternal age younger than 25 years (particularly younger than 20 years of age).
doi:10.1097/AOG.0b013e31829cbbb4
PMCID: PMC4605404  PMID: 23969795
14.  Quantifying the Number of Pregnancies at Risk of Malaria in 2007: A Demographic Study 
PLoS Medicine  2010;7(1):e1000221.
By combining data from the Malaria Atlas Project with country-specific data, Feiko ter Kuile and colleagues provide the first contemporary global estimates of the annual number of pregnancies at risk of malaria.
Background
Comprehensive and contemporary estimates of the number of pregnancies at risk of malaria are not currently available, particularly for endemic areas outside of Africa. We derived global estimates of the number of women who became pregnant in 2007 in areas with Plasmodium falciparum and P. vivax transmission.
Methods and Findings
A recently published map of the global limits of P. falciparum transmission and an updated map of the limits of P. vivax transmission were combined with gridded population data and growth rates to estimate total populations at risk of malaria in 2007. Country-specific demographic data from the United Nations on age, sex, and total fertility rates were used to estimate the number of women of child-bearing age and the annual rate of live births. Subregional estimates of the number of induced abortions and country-specific stillbirths rates were obtained from recently published reviews. The number of miscarriages was estimated from the number of live births and corrected for induced abortion rates. The number of clinically recognised pregnancies at risk was then calculated as the sum of the number of live births, induced abortions, spontaneous miscarriages, and stillbirths among the population at risk in 2007. In 2007, 125.2 million pregnancies occurred in areas with P. falciparum and/or P. vivax transmission resulting in 82.6 million live births. This included 77.4, 30.3, 13.1, and 4.3 million pregnancies in the countries falling under the World Health Organization (WHO) regional offices for South-East-Asia (SEARO) and the Western-Pacific (WPRO) combined, Africa (AFRO), Europe and the Eastern Mediterranean (EURO/EMRO), and the Americas (AMRO), respectively. Of 85.3 million pregnancies in areas with P. falciparum transmission, 54.7 million occurred in areas with stable transmission and 30.6 million in areas with unstable transmission (clinical incidence <1 per 10,000 population/year); 92.9 million occurred in areas with P. vivax transmission, 53.0 million of which occurred in areas in which P. falciparum and P. vivax co-exist and 39.9 million in temperate regions with P. vivax transmission only.
Conclusions
In 2007, 54.7 million pregnancies occurred in areas with stable P. falciparum malaria and a further 70.5 million in areas with exceptionally low malaria transmission or with P. vivax only. These represent the first contemporary estimates of the global distribution of the number of pregnancies at risk of P. falciparum and P. vivax malaria and provide a first step towards a more informed estimate of the geographical distribution of infection rates and the corresponding disease burden of malaria in pregnancy.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Malaria, a mosquito-borne parasitic disease, is a major global public-health problem. About half of the world's population is at risk of malaria, which kills about one million people every year. Most of these deaths are caused by Plasmodium falciparum, which thrives in tropical and subtropical regions. However, the most widely distributed type of malaria is P. vivax malaria, which also occurs in temperate regions. Most malaria deaths are among young children in sub-Saharan Africa, but pregnant women and their unborn babies are also very vulnerable to malaria. About 10,000 women and 200,000 babies die annually because of malaria in pregnancy, which can cause miscarriages, preterm births, and low-birth-weight births. Over the past decade, a three-pronged approach has been developed to prevent and control malaria in pregnancy. This approach consists of intermittent preventative treatment of pregnant women with antimalarial drugs, the use of insecticide-treated bed nets to protect pregnant women from the bites of infected mosquitoes, and management of malarial illness among pregnant women.
Why Was This Study Done?
This strategy has begun to reduce the burden of malaria among pregnant women and their babies but the resources available for its introduction are very limited in many of the developing countries where malaria is endemic (always present). Policy makers in these countries need to know the number of pregnancies at risk of malaria so that they can use their resources wisely. However, although the World Health Organization recently estimated that more than 30 million African women living in malaria endemic areas become pregnant and are at risk for malaria each year, there are no comprehensive and contemporary estimates of the number of pregnancies at risk of malaria for endemic areas outside Africa. In this study, the researchers derive global estimates of the number of women who became pregnant in 2007 in areas with P. falciparum and P. vivax transmission.
What Did the Researchers Do and Find?
The researchers estimated the sizes of populations at risk of malaria in 2007 by combining maps of the global limits of P. vivax and P. falciparum transmission with data on population densities. They used data from various sources to calculate the annual number of pregnancies (the sum of live births, induced abortions, miscarriages, and still births) in each country. Finally, they calculated the annual number of pregnancies at risk of malaria in each country by multiplying the number of pregnancies in the entire country by the fraction of the population living within the spatial limits of malaria transmission in that country. In 2007, they calculate, 125.2 million pregnancies occurred in areas with P. falciparum and/or P. vivax transmission. These pregnancies—60% of all pregnancies globally—resulted in 82.6 million live births. 77.4 million at-risk pregnancies occurred in Southeast Asia and the Western Pacific (India had the most pregnancies at risk of both P. falciparum and P. vivax malaria), 30.3 million in Africa, 13.1 million in Europe and the Eastern Mediterranean, and 4.3 million in the Americas. 54.7 million at-risk pregnancies occurred in regions with stable P. falciparum transmission (more than one case of malaria per 10,000 people per year), whereas 70.5 million occurred in areas with low malaria transmission or P. vivax transmission only.
What Do These Findings Mean?
These findings are the first contemporary estimates of the global distribution of the number of pregnancies at risk of P. falciparum and P. vivax malaria. They do not provide any information on the actual incidence of malaria during pregnancy or the health burden on mothers and unborn babies. They simply represent “any risk” of exposure. So, for example, the researchers calculate that only about 5,000 actual malaria infections may occur annually among the 70.5 million at-risk pregnancies in areas with very low malaria transmission or with P. vivax transmission only. Furthermore, these findings do not allow for the seasonality of malaria—pregnancies that occur outside of the transmission season may be at no or very low risk of malaria. Nevertheless, the estimates reported in this study are an important first step towards a spatial map of the burden of malaria in pregnancy and should help policy makers allocate resources for research into and control of this important public-health problem.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000221.
Information is available from the World Health Organization on malaria and on malaria in pregnancy (in several languages)
The US Centers for Disease Control and Prevention also provides information on malaria and on malaria in pregnancy (in English and Spanish)
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 and also provides a comprehensive bibliographic database of published and unpublished literature relating to malaria in pregnancy
The Malaria Atlas Project provides maps of malaria transmission around the world
MedlinePlus provides links to additional information on malaria (in English and Spanish)
doi:10.1371/journal.pmed.1000221
PMCID: PMC2811150  PMID: 20126256
15.  National, Regional, and Global Trends in Infertility Prevalence Since 1990: A Systematic Analysis of 277 Health Surveys 
PLoS Medicine  2012;9(12):e1001356.
Gretchen Stevens and colleagues use information from demographic reproductive health surveys to estimate the global, regional, and country levels, patterns, and trends in infertility between 1990 and 2010.
Background
Global, regional, and national estimates of prevalence of and tends in infertility are needed to target prevention and treatment efforts. By applying a consistent algorithm to demographic and reproductive surveys available from developed and developing countries, we estimate infertility prevalence and trends, 1990 to 2010, by country and region.
Methods and Findings
We accessed and analyzed household survey data from 277 demographic and reproductive health surveys using a consistent algorithm to calculate infertility. We used a demographic infertility measure with live birth as the outcome and a 5-y exposure period based on union status, contraceptive use, and desire for a child. We corrected for biases arising from the use of incomplete information on past union status and contraceptive use. We used a Bayesian hierarchical model to estimate prevalence of and trends in infertility in 190 countries and territories. In 2010, among women 20–44 y of age who were exposed to the risk of pregnancy, 1.9% (95% uncertainty interval 1.7%, 2.2%) were unable to attain a live birth (primary infertility). Out of women who had had at least one live birth and were exposed to the risk of pregnancy, 10.5% (9.5%, 11.7%) were unable to have another child (secondary infertility). Infertility prevalence was highest in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Levels of infertility in 2010 were similar to those in 1990 in most world regions, apart from declines in primary and secondary infertility in Sub-Saharan Africa and primary infertility in South Asia (posterior probability [pp] ≥0.99). Although there were no statistically significant changes in the prevalence of infertility in most regions amongst women who were exposed to the risk of pregnancy, reduced child-seeking behavior resulted in a reduction of primary infertility among all women from 1.6% to 1.5% (pp = 0.90) and a reduction of secondary infertility among all women from 3.9% to 3.0% (pp>0.99) from 1990 to 2010. Due to population growth, however, the absolute number of couples affected by infertility increased from 42.0 million (39.6 million, 44.8 million) in 1990 to 48.5 million (45.0 million, 52.6 million) in 2010. Limitations of the study include gaps in survey data for some countries and the use of proxies to determine exposure to pregnancy.
Conclusions
We analyzed demographic and reproductive household survey data to reveal global patterns and trends in infertility. Independent from population growth and worldwide declines in the preferred number of children, we found little evidence of changes in infertility over two decades, apart from in the regions of Sub-Saharan Africa and South Asia. Further research is needed to identify the etiological causes of these patterns and trends.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Reproductive health is a priority global health area: the target for Millennium Development Goal 5B is to provide universal access to reproductive health by 2015. The indicators for monitoring progress in reaching this target are contraceptive prevalence rate, adolescent birth rate, antenatal care coverage, and the unmet need for family planning. Infertility, the inability to conceive after a prolonged period (the length of time varies in different definitions) of unprotected intercourse, is a critical but much neglected aspect of reproductive health. The inability to have children affects couples worldwide and causes emotional and psychological distress in both men and women. Many factors—including physiological, genetic, environmental, and social— contribute to infertility. According to the World Health Organization, infertility resulting from sexually transmitted diseases or reproductive tract infections is particularly problematic in Africa and Latin America.
Why Was This Study Done?
The researchers used a uniform measure of infertility that incorporated live birth as the outcome of interest (as this information is more commonly reported than pregnancies), a five-year “exposure period,” that is, a five-year period of being in an intimate relationship, not using contraceptives, and wanting a child (as the researchers calculated that this period was necessary to accommodate the time it takes to become pregnant and have a child, and to allow for incomplete information on frequency of unprotected intercourse). The researchers used a statistical model (Bayesian hierarchical model) to generate estimates for levels and trends of infertility in 190 countries over the time period 1990 to 2010 using information collected from national demographic and reproductive health surveys. The most data was available for South Asia and Sub-Saharan Africa.
What Did the Researchers Do and Find?
The researchers found that in 2010, 1.9% of women aged 20–44 years who wanted to have children were unable to have their first live birth (primary infertility), and 10.5% of women with a previous live birth were unable to have an additional live birth (secondary infertility). The researchers found that the levels of infertility were similar in 1990 and 2010, with only a slight overall decrease in primary infertility (0.1%, but with a more pronounced drop in Sub-Saharan Africa and South Asia) and a modest overall increase in secondary infertility (0.4%). Age affected infertility rates: the prevalence of primary infertility was higher among women aged 20–24 years than among older women. The age pattern was reversed and even more pronounced for secondary infertility. And primary infertility rates among women wanting children also varied by region, from 1.5% in Latin America and the Caribbean in 2010, to 2.6% in North Africa and the Middle East. With a few exceptions, global and country patterns of secondary infertility were similar to those of primary infertility.
What Do These Findings Mean?
These findings suggest that in 2010, an estimated 48.5 million couples worldwide were unable to have a child after five years. However, these findings also suggest that global levels of primary and secondary infertility hardly changed between 1990 and 2010. It is important to note that an infertility measure based on ability to become pregnant (rather than having a live birth—the outcome used in this study) may show different levels of infertility, and using an exposure period shorter than the five years used in this study would produce higher rates of infertility. However, because of the lack of widespread data collection on time to pregnancy, the methods used and results shown in this study provide useful insights into global, regional, and country patterns and trends in infertility.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001356.
The World Health Organization has information on reproductive health
Wikipedia defines infertility and gives some useful information (note that Wikipedia is a free online encyclopedia that anyone can edit)
Patient friendly information on infertility can be found at PubMed Health and NHS Choices
doi:10.1371/journal.pmed.1001356
PMCID: PMC3525527  PMID: 23271957
16.  The Effect of Changing Patterns of Obstetric Care in Scotland (1980–2004) on Rates of Preterm Birth and Its Neonatal Consequences: Perinatal Database Study 
PLoS Medicine  2009;6(9):e1000153.
Jane Norman and colleagues analyzed linked perinatal surveillance data in Scotland and find that between 1980 and 2004 increases in spontaneous and medically induced preterm births contributed equally to the rising rate of preterm births.
Background
Rates of preterm birth are rising worldwide. Studies from the United States and Latin America suggest that much of this rise relates to increased rates of medically indicated preterm birth. In contrast, European and Australian data suggest that increases in spontaneous preterm labour also play a role. We aimed, in a population-based database of 5 million people, to determine the temporal trends and obstetric antecedents of singleton preterm birth and its associated neonatal mortality and morbidity for the period 1980–2004.
Methods and Findings
There were 1.49 million births in Scotland over the study period, of which 5.8% were preterm. We found a percentage increase in crude rates of both spontaneous preterm birth per 1,000 singleton births (10.7%, p<0.01) and medically indicated preterm births (41.2%, p<0.01), which persisted when adjusted for maternal age at delivery. The greater proportion of spontaneous preterm births meant that the absolute increase in rates of preterm birth in each category were similar. Of specific maternal complications, essential and pregnancy-induced hypertension, pre-eclampsia, and placenta praevia played a decreasing role in preterm birth over the study period, with gestational and pre-existing diabetes playing an increasing role. There was a decline in stillbirth, neonatal, and extended perinatal mortality associated with preterm birth at all gestation over the study period but an increase in the rate of prolonged hospital stay for the neonate. Neonatal mortality improved in all subgroups, regardless of obstetric antecedent of preterm birth or gestational age. In the 28 wk and greater gestational groups we found a reduction in stillbirths and extended perinatal mortality for medically induced but not spontaneous preterm births (in the absence of maternal complications) although at the expense of a longer stay in neonatal intensive care. This improvement in stillbirth and neonatal mortality supports the decision making behind the 34% increase in elective/induced preterm birth in these women. Although improvements in neonatal outcomes overall are welcome, preterm birth still accounts for over 66% of singleton stillbirths, 65% of singleton neonatal deaths, and 67% of infants whose stay in the neonatal unit is “prolonged,” suggesting this condition remains a significant contributor to perinatal mortality and morbidity.
Conclusions
In our population, increases in spontaneous and medically induced preterm births have made equal contributions to the rising rate of preterm birth. Despite improvements in related perinatal mortality, preterm birth remains a major obstetric and neonatal problem, and its frequency is increasing.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Most pregnancies last about 40 weeks but increasing numbers of babies are being born preterm, before they reach 37 weeks of gestation (gestation is the period during which a baby develops in its mother). Nowadays in the US, for example, more than half a million babies arrive earlier than expected every year (1 in 8 babies). Although improvements in the care of newborn babies (neonatal care) mean that preterm babies are more likely to survive than in the past, preterm birth remains the single biggest cause of infant death in many developed countries, and many preterm babies who survive have long-term health problems and disabilities, particularly those born before 32 weeks of gestation. Preterm births can be spontaneous or medically induced. At present, it impossible to predict which mothers will spontaneously deliver early and there is no effective way to prevent these preterm births; medically induced early labor is undertaken when either the unborn baby or mother would be at risk if the pregnancy continued to full term.
Why Was This Study Done?
Preterm birth rates need to be reduced, but before this can be done it is important to know how the causes of preterm birth, the numbers of preterm stillbirths, and the numbers of preterm babies who die at birth (neonatal deaths) or soon after (perinatal deaths) are changing with time. If, for example, the rise in preterm births is mainly due to an increase in medically induced labor and if this change in practice has reduced neonatal deaths, it would be unwise to try to reduce the preterm birth rate by discouraging medically induced preterm births. So far, data from the US and Latin America suggest that the increase in preterm births in these countries is solely due to increased rates of medically induced preterm births. However, in Europe and Australia, the rate of spontaneous preterm births also seems to be increasing. In this study, the researchers examine the trends over time and causes of preterm birth and of neonatal death and illness in Scotland over a 25-year period.
What Did the Researchers Do and Find?
By searching a Scottish database of linked maternity records and infant health and death records, the researchers identified 1.49 million singleton births that occurred between 1980 and 2004 of which nearly 90,000 were preterm births. Over the study period, the rates of spontaneous and of medically induced preterm births per 1,000 births increased by 10.7% and 41.2%, respectively, but because there were more spontaneous preterm births than medically induced preterm births, the absolute increase in the rates of each type of birth was similar. Several maternal complications including preeclampsia (a condition that causes high blood pressure) and placenta previa (covering of the opening of the cervix by the placenta) played a decreasing role in preterm births over the study period, whereas gestational and preexisting diabetes played an increasing role. Finally, there was a decline in stillbirths and in neonatal and perinatal deaths among preterm babies, although more babies remained in the hospital longer than 7 days after birth. More specifically, after 28 weeks of gestation, stillbirths and perinatal deaths decreased among medically induced preterm births but not among spontaneous preterm births.
What Do These Findings Mean?
These findings indicate that in Scotland between 1980 and 2004, increases in spontaneous and medically induced preterm births contributed equally to the rising rate of preterm births. Importantly, they also show that the increase in induced preterm births helped to reduce stillbirths and neonatal and perinatal deaths, a finding that supports the criteria that clinicians currently use to decide whether to induce an early birth. Nevertheless, preterm births still account for two-thirds of all stillbirths, neonatal deaths, and extended neonatal stays in hospital and thus cause considerable suffering and greatly increase the workload in neonatal units. The rates of such births consequently need to be reduced and, for Scotland at least, ways will have to be found to reduce the rates of both spontaneous and induced preterm births to achieve this goal while continuing to identify those sick babies who need to be delivered early to give them the best chance of survival.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000153
Tommys is a nonprofit organization that funds research and provides information on the causes and prevention of miscarriage, premature birth, and stillbirth
The March of Dimes, a nonprofit organization for pregnancy and baby health, provides information on preterm birth (in English and Spanish)
The Nemours Foundation, another nonprofit organization for child health, also provides information on premature babies (in English and Spanish)
The US Centers for Disease Control and Prevention provides information on maternal and infant health (in English and Spanish)
The US National Women's Health Information Center has detailed information about pregnancy, including a section on pregnancy complications
MedlinePlus provides links to other information on premature babies and to information on pregnancy (in English and Spanish)
doi:10.1371/journal.pmed.1000153
PMCID: PMC2740823  PMID: 19771156
17.  Prevalence of and factors associated with daily smoking among Inner Mongolia medical students in China: a cross-sectional questionnaire survey 
Background
To date, no study on smoking behavior of medical students in Inner Mongolia has been reported. The aim of the present study was to determine the 1-month prevalence of and factors associated with daily smoking among medical students in Inner Mongolia of China, to assist interventions designed to reduce the smoking behavior of medical college students in this region.
Methods
During December 2010 and January 2011 a cross-sectional survey was conducted among medical students at the Inner Mongolia Medical College using a self-administered questionnaire. The questionnaire consisted of three sections: students’ basic information, attitude on smoking behavior, and smoking status of the student daily smokers. Students who smoked every day in the last 30 days were regarded as daily smokers. Factors associated with smoking were identified using binary logistic regression analysis.
Results
A total of 6044 valid surveys were returned. The overall prevalence of daily smoking was 9.8% while the prevalence of daily smoking among males and females were 29.4% and 1.7%, respectively. Males in the Faculty of Medicine Information Management had the highest daily smoking rate (48.9%). Logistic regression models found that the main factors associated with daily smoking among male medical students were highest year of study (OR = 3.62; CI: 1.18–11.05); attitude towards smoking behavior Do not care about people smoking around you (OR = 2.75; CI: 2.08–3.64); and Smoking is harmful to their health (OR = 4.40; CI: 2.21–8.75). The main factor associated with daily smoking among female medical students was attitude towards smoking behavior Eliminate smoking on campus (OR = 0.11; CI: 0.06–0.23). Both for male and female medical students, there was no association between ethnicity and cigarette daily smoking. In regard to smoking status, more than 60% of daily smokers began smoking in high school, 61.3% smoked less than 5 cigarettes per day, 62.9% of the daily smokers’ families opposed their smoking behavior, and after an hour of not smoking 74.6% daily smokers did not feel uncomfortable.
Conclusions
Antismoking education should be further promoted in Inner Mongolia medical students, with consideration given to the factors associated with daily smoking behavior found in the present study.
doi:10.1186/1747-597X-7-20
PMCID: PMC3419670  PMID: 22591602
Daily smoking; Behavior; Medical students; Prevalence
18.  Prevalence of orofacial clefts in Korean live births 
Obstetrics & Gynecology Science  2015;58(3):196-202.
Objective
The aim of this study was to investigate the prevalence of orofacial clefts and identify the characteristics of other birth defects associated with orofacial clefts in Korea.
Methods
This study used data from the Congenital Anomaly Survey conducted by the Korea Institute for Health and Social Affairs. The survey was conducted on birth defects documented during 2005 to 2006 in 2,348 medical institutes in Korea. This study was performed using data from medical insurance claims of the National Health Insurance Corporation. The prevalence of orofacial clefts was defined as the number of cases per 10,000 live births.
Results
Among the 883,184 live births, 25,335 infants had birth defects, which included 980 infants with orofacial clefts. The prevalence of total orofacial clefts in the total live births was 11.09 per 10,000, accounting for 3.9% of all birth defects. The most common orofacial cleft was cleft palate only (n=492), followed by cleft lip only (n=245) and cleft lip with cleft palate (n=243), with prevalence rates of 5.57, 2.77, 2.75 per 10,000 live births, respectively. While malformations of the circulatory system; digestive system; eyes, ears, face, and neck; and musculoskeletal system were most frequently encountered among infants with a cleft lip with or without a cleft palate, anomalies of most organ systems were notably observed among infants with cleft palate only.
Conclusion
The prevalence of orofacial clefts in Korea was similar or slightly lower than that of other countries. This study informs present status of orofacial clefts and gives baseline data to lay the foundation stone for Korea's registry system of orofacial clefts.
doi:10.5468/ogs.2015.58.3.196
PMCID: PMC4444515  PMID: 26023668
Cleft lip; Cleft palate; Korea; Orofacial clefts; Prevalence
19.  Racial/Ethnic Variations in the Prevalence of Selected Major Birth Defects, Metropolitan Atlanta, 1994–2005 
Public Health Reports  2012;127(1):52-61.
SYNOPSIS
Objectives
Birth defects are the leading cause of infant mortality and are responsible for substantial child and adult morbidity. Documenting the variation in prevalence of birth defects among racial/ethnic subpopulations is critical for assessing possible variations in diagnosis, case ascertainment, or risk factors among such groups.
Methods
We used data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects registry with active case ascertainment. We estimated the racial/ethnic variation in prevalence of 46 selected major birth defects among live births, stillbirths, and pregnancy terminations at >20 weeks gestation among mothers residing in the five central counties of metropolitan Atlanta between 1994 and 2005, adjusting for infant sex, maternal age, gravidity, and socioeconomic status (SES). We also explored SES as a potential effect measure modifier.
Results
Compared with births to non-Hispanic white women, births to non-Hispanic black women had a significantly higher prevalence of five birth defects and a significantly lower prevalence of 10 birth defects, while births to Hispanic women had a significantly higher prevalence of four birth defects and a significantly lower prevalence of six birth defects. The racial/ethnic disparities in the prevalence of some defects varied by SES, but no clear pattern emerged.
Conclusions
Racial/ethnic disparities were suggested in 57% of included birth defects. Disparities in the prevalence of birth defects may result from different underlying genetic susceptibilities; exposure to risk factors; or variability in case diagnosis, ascertainment, or reporting among the subpopulations examined. Policies that improve early diagnosis of birth defects could reduce associated morbidity and mortality.
PMCID: PMC3234397  PMID: 22298922
20.  Descriptive epidemiology of selected birth defects, areas of Lombardy, Italy, 1999 
Background
Birth defects are a leading cause of neonatal and infant mortality in Italy, however little is known of the etiology of most defects. Improvements in diagnosis have revealed increasing numbers of clinically insignificant defects, while improvements in treatment have increased the survival of those with more serious and complex defects. For etiological studies, prevention, and management, it is important to have population-based monitoring which provides reliable data on the prevalence at birth of such defects.
Methods
We recently initiated population-based birth defect monitoring in the Provinces of Mantova, Sondrio and Varese of the Region of Lombardy, northern Italy, and report data for the first year of operation (1999). The registry uses all-electronic source files (hospital discharge files, death certificates, regional health files, and pathology reports) and a proven case-generation methodology, which is described.
The data were checked manually by consulting clinical records in hospitals. Completeness was checked against birth certificates by capture-recapture. Data on cases were coded according to the four-digit malformation codes of the International Classification of Diseases, Ninth Revision (ICD-9). We present data only on selected defects.
Results
We found 246 selected birth defects in 12,008 live births in 1999, 148 among boys and 98 among girls. Congenital heart defects (particularly septal defects) were the most common (90.8/10,000), followed by defects of the genitourinary tract (34.1/10, 000) (particularly hypospadias in boys), digestive system (23.3/10,000) and central nervous system (14.9/10,000), orofacial clefts (10.8/10,000) and Down syndrome (8.3/10,000). Completeness was satisfactory: analysis of birth certificates resulted in the addition of two birth defect cases to the registry.
Conclusion
This is the first population-based analysis on selected major birth defects in the Region. The high birth prevalences for septal heart defect and hypospadias are probably due to the inclusion of minor defects and lack of coding standardization; the latter problem also seems important for other defects. However the data produced are useful for estimating the demands made on the health system by babies with birth defects.
doi:10.1186/1478-7954-5-4
PMCID: PMC1894780  PMID: 17531093
21.  Severe birth defects in children perinatal exposed to HIV from a “real-world” setting: Infectious Diseases National Institute, Bucharest, Romania 
Journal of the International AIDS Society  2014;17(4Suppl 3):19699.
Introduction
The shift in epidemic trends in recent years in Romania shows new problems in regard of HIV vertical transmission, firstly in intravenous drug user's mothers co-infected with hepatitis viruses and with social problems, and secondly the children of young mothers with an old HIV infection and long antiretroviral therapy history.
Materials and Methods
We studied all HIV perinatal exposed children routinely followed up in the Paediatric Department of the National Institute of Infectious Diseases, since January 1st 2006 till December 31st 2012. The analyses consisted of describing the birth defects and association with certain risk factors: gender, mother's age at birth and exposure to antiretrovirals in the first trimester of pregnancy.
Results
We analyzed 244 children born to HIV-infected mothers. The incidence of HIV infection was 16.39%. The rate of birth defects was 39.34% (96/244 cases). The most frequent findings were cardiac malformations (47/96), followed by musculoskeletal defects (24/96), neurologic defects (20/96), urogenital malformations (13/96), digestive tract defects (3/93), metabolic disorders (2/96) and genetic disorders (2/96). We found nine cases of severe congenital anomalies: complex heart defect, total congenital aganglionic megacolon, anal imperforation, Dandy-Walker syndrome, gangliosidosis, Niemann-Pick syndrome, Down syndrome, true hermaphroditism and cleft palate. Two children died during first year of life due to severe malformations. 9% of cases had associated malformations. The gender rate was in favour of males in group with birth defects (58/38) and with no birth defects (82/66). The median age at birth in mothers was 22 years, similar in both groups. The highest mean age at birth was in offspring's mothers with neurologic congenital defects 25, 15 years old, but is not statistically significant (p=0.1). In the studied period the highest number of birth defects were found in 2012, 37 children, compared with less than 15 in previous years (not statistically significant, p=0.07). In our studied patients the risk of birth defects was not statistically associated with HIV transmission or with exposure to antiretrovirals before and in first trimester of pregnancy (p=0.88).
Conclusion
The rate of birth defects among HIV-exposed children was not significantly associated with antiretroviral exposure, but we identify very rare and severe congenital conditions. We have noticed also a trend to increasing number of birth defects in 2012 among studied patients compared to previous years.
doi:10.7448/IAS.17.4.19699
PMCID: PMC4225364  PMID: 25397447
22.  Screening high-risk clusters for developing birth defects in mothers in Shanxi Province, China: application of latent class cluster analysis 
Background
Few studies on cluster-based synthetic effects of multiple risk factors for birth defects have been reported. The present study aimed to identify maternal exposure clusters, explore the association between clusters of risk factors and birth defects, and further screen women with high risk for birth defects among expectant mothers.
Methods
Data were drawn from a large-scale, retrospective epidemiological survey of birth defects from 2006 to 2008 in six counties of Shanxi Province, China, using a three-level stratified random cluster sampling technique. Overall risk factors were extracted using eight synthetic variables summed and examined as a total risk factor score: maternal delivery age, genetic factors, medical history, nutrition and folic acid deficiency, maternal illness in pregnancy, drug use in pregnancy, environmental risk factors in pregnancy, and unhealthy maternal lifestyle in pregnancy. Latent class cluster analysis was used to identify maternal exposure clusters based on these synthetic variables. Adjusted odds ratios (AOR) were used to explore associations between clusters and birth defects, after adjusting for confounding variables using logistic regression.
Results
Three latent maternal exposure clusters were identified: a high-risk (6.15 %), a moderate-risk (22.39 %), and a low-risk (71.46 %) cluster. The prevalence of birth defects was 14.08 %, 0.85 %, and 0.52 % for the high-, middle- and low-risk clusters respectively. After adjusting for maternal demographic variables, women in the high-risk cluster were nearly 31 times (AOR: 30.61, 95 % CI: [24.87, 37.67]) more likely to have an infant with birth defects than low-risk women.
Conclusions
A high-risk group of mothers in an area with a high risk for birth defects were screened in our study. Targeted interventions should be conducted with women of reproductive age to improve neonatal birth outcomes in areas with a high risk of birth defects.
doi:10.1186/s12884-015-0783-x
PMCID: PMC4687365  PMID: 26694165
Maternal exposure; Clusters; Birth defects; China; Latent class cluster analysis
23.  Birth Defects in Singleton versus Multiple ART Births in Japan (2004–2008) 
Journal of Pregnancy  2011;2011:285706.
The purpose of the present study was to evaluate the relative risk (RR) of multiple births for birth defects after assisted reproductive technology (ART) using Japanese nationwide data from 2004 to 2008 with singletons as the reference group. In multiples compared to singletons, the percentage of birth defects per pregnancy were significantly higher (RR = 1.88, 95% confidence interval (CI) 1.60–2.13), the percentage of birth defects per live birth was not significantly higher (RR = 0.90, 95% CI 0.78–1.05 or RR = 0.94, 95% CI 0.81–1.10), and the early neonatal mortality rate was significantly higher (RR = 2.68, 95% CI 1.52–4.70 or RR = 2.80, 95% CI 1.60–4.92). The early neonatal mortality per 10,000 live births was slightly higher in ART (5.09) than in the general population (3.86). We concluded that the impact of birth defects after ART would be larger in families with multiples compared to families with singletons, since the mean number of children would be larger in the former.
doi:10.1155/2011/285706
PMCID: PMC3228342  PMID: 22175021
24.  Birth Size and Breast Cancer Risk: Re-analysis of Individual Participant Data from 32 Studies 
PLoS Medicine  2008;5(9):e193.
Background
Birth size, perhaps a proxy for prenatal environment, might be a correlate of subsequent breast cancer risk, but findings from epidemiological studies have been inconsistent. We re-analysed individual participant data from published and unpublished studies to obtain more precise estimates of the magnitude and shape of the birth size–breast cancer association.
Methods and Findings
Studies were identified through computer-assisted and manual searches, and personal communication with investigators. Individual participant data from 32 studies, comprising 22,058 breast cancer cases, were obtained. Random effect models were used, if appropriate, to combine study-specific estimates of effect. Birth weight was positively associated with breast cancer risk in studies based on birth records (pooled relative risk [RR] per one standard deviation [SD] [= 0.5 kg] increment in birth weight: 1.06; 95% confidence interval [CI] 1.02–1.09) and parental recall when the participants were children (1.02; 95% CI 0.99–1.05), but not in those based on adult self-reports, or maternal recall during the woman's adulthood (0.98; 95% CI 0.95–1.01) (p for heterogeneity between data sources = 0.003). Relative to women who weighed 3.000–3.499 kg, the risk was 0.96 (CI 0.80–1.16) in those who weighed < 2.500 kg, and 1.12 (95% CI 1.00–1.25) in those who weighed ≥ 4.000 kg (p for linear trend = 0.001) in birth record data. Birth length and head circumference from birth records were also positively associated with breast cancer risk (pooled RR per one SD increment: 1.06 [95% CI 1.03–1.10] and 1.09 [95% CI 1.03–1.15], respectively). Simultaneous adjustment for these three birth size variables showed that length was the strongest independent predictor of risk. The birth size effects did not appear to be confounded or mediated by established breast cancer risk factors and were not modified by age or menopausal status. The cumulative incidence of breast cancer per 100 women by age 80 y in the study populations was estimated to be 10.0, 10.0, 10.4, and 11.5 in those who were, respectively, in the bottom, second, third, and top fourths of the birth length distribution.
Conclusions
This pooled analysis of individual participant data is consistent with birth size, and in particular birth length, being an independent correlate of breast cancer risk in adulthood.
Editors' Summary
Background.
Last year, more than one million women discovered that they had breast cancer. In the US, nearly 200,000 women will face the same diagnosis this year and 40,000 will die because of breast cancer. Put another way, about one in eight US women will have breast cancer during her lifetime. Like all cancers, breast cancer begins when cells acquire genetic changes that allow them to divide uncontrollably and to move around the body (metastasize). This uncontrolled division leads to the formation of a lump that can be detected by mammography (a breast X-ray) or by manual examination of the breasts. Breast cancer is treated by surgical removal of the lump or, if the cancer has started to spread, by removal of the whole breast (mastectomy). Surgery is usually followed by radiotherapy, chemotherapy, and other treatments designed to kill any remaining cancer cells. Unlike some cancers, the outlook for women with breast cancer is good. In the US, for example, nearly 90% of affected women are still alive five years after their diagnosis.
Why Was This Study Done?
Scientists have identified several factors that increase a woman's risk of developing breast cancer by comparing the characteristics of populations of women with and without breast cancer. Well-established risk factors include increasing age, not having children, and having a late menopause, but another potential risk factor for breast cancer is birth size. A baby's weight, length, and head circumference at birth (three related measures of birth size) depend on the levels of hormones (including estrogen, a hormone that often affects breast cancer growth) and other biological factors to which the baby is exposed during pregnancy—its prenatal environment. The idea that prenatal environment might also affect breast cancer risk in later life was first proposed in 1990, but the findings of studies that have tried to investigate this possibility have been inconsistent. Here, the researchers re-analyze individual participant data from a large number of studies into women's health conducted in Europe, Northern America, and China to get more precise information about the association between birth size and breast cancer risk.
What Did the Researchers Do and Find?
The researchers identified 32 published and unpublished studies that had collected information on birth size and on the occurrence of breast cancer. They then obtained the individual participant data from these studies, which involved more than 22,000 women who had developed breast cancer and more than 600,000 women who had not. Their analyses of these data show that birth weight was positively associated with breast cancer risk in those studies where this measurement was recorded at birth or based on parental recall during the study participant's childhood (but not in those studies in which birth weight was self-reported or maternally recalled during the participant's adulthood). For example, women with recorded birth weights of more than 4 kg or more had a 12% higher chance of developing breast cancer than women who weighed 3–3.5 kg at birth. Birth length and head circumference were also positively associated with breast cancer risk, but birth length was the strongest single predictor of risk. Finally, the amount by which birth size affected breast cancer risk was not affected by allowing for other established risk factors.
What Do These Findings Mean?
These findings provide strong evidence that birth size—in particular, birth length—is a marker of a woman's breast cancer risk in adulthood although the mechanisms underlying this association are unclear. The researchers note that the observed effect of birth size on breast cancer risk is of a similar magnitude to that of other more established risk factors and estimate that 5% of all breast cancers in developed countries could be caused by a high birth size. Because practically all the studies included in this pooled analysis were done in developed countries, these findings may not hold for developing countries. Further investigations into how the prenatal environment may affect breast cancer risk might identify new ways to prevent this increasingly common cancer.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050193.
This study is further discussed in a PLoS Medicine Perspective by Trichopoulos and Lagiou
The US National Cancer Institute provides detailed information for patients and health professionals on all aspects of breast cancer, including information on risk factors for breast cancer (in English and Spanish)
The MedlinePlus Encyclopedia provides information for patients about breast cancer; Medline Plus also provides links to many other breast cancer resources (in English and Spanish)
The UK charity Cancerbackup also provides detailed information about breast cancer
Cancer Research UK is the UK's leading charity dedicated to cancer research
doi:10.1371/journal.pmed.0050193
PMCID: PMC2553821  PMID: 18828667
25.  Morbidity due to acute lower respiratory infection in children with birth defects: a total population-based linked data study 
BMC Pediatrics  2014;14:80.
Background
Acute lower respiratory infections (ALRIs) are leading causes of hospitalisation in children. Birth defects occur in 5% of live births in Western Australia (WA). The association between birth defects and ALRI hospitalisation is unknown.
Methods
We conducted a retrospective cohort study of 245,249 singleton births in WA (1996-2005). Population-based hospitalisation data were linked to the WA Register of Developmental Anomalies to investigate ALRI hospitalisations in children with and without birth defects. We used negative binomial regression to estimate associations between birth defects and number of ALRI hospitalisations before age 2 years, adjusting for known risk factors.
Results
Overall, 9% of non-Aboriginal children and 37% of Aboriginal children with birth defects had at least one ALRI admission before age 2 years. Aboriginal children (IRR 2.3, 95% CI: 1.9-2.8) and non-Aboriginal children (IRR 2.0, 95% CI: 1.8-2.2) with birth defects had higher rates of hospitalisation for an ALRI than children with no birth defects. Rates of ALRI hospitalisation varied by type of defect but were increased for all major birth defects categories, the highest rate being for children with Down syndrome (IRR 8.0, 95% CI: 5.6-11.5). The rate of ALRI hospitalisation was 3 times greater in children with multiple birth defects than in those with isolated defects.
Conclusions
Children with birth defects experience higher rates of hospitalisation for ALRIs before age 2 years than children with no birth defects. Optimal vaccination coverage and immunoprophylaxis for specific categories of birth defects would assist in reducing hospitalisation rates for ALRI.
doi:10.1186/1471-2431-14-80
PMCID: PMC3987821  PMID: 24661413
Acute lower respiratory infections; Birth defects; Aboriginal Australian children; Linked population health data; Hospitalisations

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