Building capacity for birth defects surveillance in Africa: Implementation of an intermediate birth defects surveillance workshop

Each year around the world, it is estimated that 300,000 neonates are born with a neural tube defect. Many countries, however, are still lacking comprehensive birth defects surveillance registries. Comprehensive birth defects surveillance systems can help countries understand the magnitude and distribution of the problem. These systems can also provide information about biological, contextual, social and environmental determinants of birth defects. This information in turn can be used to identify effective and implementable solutions, and to evaluate prevention and management strategies to improve quality performance. This paper summarizes the development and implementation of an online pre-course training and in-person surveillance workshop conducted between 2014 December and 2015 March for representatives from six African countries. Feedback given by participants provided valuable lessons learned that can be applied to subsequent trainings and workshops.

Preconception care policy, guidelines, recommendations and services across six European countries: Belgium (Flanders), Denmark, Italy, the Netherlands, Sweden and the United Kingdom

OBJECTIVES

Preconception care is important for the screening, prevention and management of risk factors that affect pregnancy outcomes. We aimed to investigate pre-pregnancy care policies, guidelines, recommendations and services in six European countries.

METHODS

In 2013, an electronic search and investigation was undertaken of preconception policy, guidelines, recommendations and services available to healthcare professionals and the general public in six European countries: Belgium (Flanders), Denmark, Italy, the Netherlands, Sweden and the United Kingdom. Findings were compared within five categories: Governmental policy and legislation; Professional bodies and organisations; Healthcare providers; Charitable organisations; Web-based public information and internet sites.

RESULTS

All countries had preconception recommendations for women with chronic diseases, such as diabetes and epilepsy. Recommendations for healthy women and men were fragmented and inconsistent. Preconception guidance was often included in antenatal and pregnancy guidelines. Differences between countries were seen with regard to nutritional and lifestyle advice particularly in relation to fish, caffeine and alcohol consumption, and vitamin supplementation.

CONCLUSIONS

Current guidelines are heterogeneous. Collaborative research across Europe is required in order to develop evidence-based guidelines for preconception health and care. There is a need to establish a clear strategy for promoting advice and guidance within the European childbearing population.

Prevalence of maternal preconception risk factors: an Italian multicenter survey

Objectives

Adequate preconception maternal health care is essential to reduce the risk of unwanted pregnancy outcomes and complications. Still, many women are exposed to a number of unhealthy risk factors both before and early in pregnancy. This study aimed to estimate the prevalence of a number of important preconception risk factors using data from a recent multicenter study in Italy.

Methods

The study was based on cross-sectional data from seven maternity clinics located in six different regions in Italy during the period January – June, 2012. Data on maternal preconception risk factors and characteristics were collected from 1,892 women who delivered healthy children and 320 women who were pregnant in the first trimester.

Results

About 97% of the women (n = 2,212) were exposed to one or more preconception risk factors. The overall prevalence of the most essential maternal risk factors was as follows: 41% had a age ≥35 years, 36% mistimed or did not intend their pregnancy, 58% did not request a preconception health visit to their doctor, 76% did not use folic acid supplements before pregnancy, 26% smoked at the last menstrual period, 19% had a body mass index ≥25 kg/m² before pregnancy, and 10% suffered from pregestational chronic diseases. The prevalence of certain variables varied between the maternity clinics.

Conclusions

Many Italian women are exposed to a number of preconception risk factors that have been associated with adverse pregnancy complications and outcomes. More effective intervention programs to improve preconception health in Italian women are strongly needed.

Women participating in a web-based preconception study have a high prevalence of risk factors for adverse pregnancy outcomes

Background

Adverse pregnancy outcomes (APOs) can be increased by preconception risk factors and lifestyles.

We measured the prevalence of preconception risk factors for APOs in a population of Italian women of childbearing age enrolled in a web-based study.

Methods

Participants were enrolled through a web platform (http://www.mammainforma.it). After enrollment, participants filled in a questionnaire regarding socio-demographic characteristics, clinical data and preconception risk factors for adverse pregnancy outcomes. Through logistic regression, we explored how the prevalence of risk factors was affected by age, education level, employment, parity, physician’s recommendation and knowledge of the specific risk factor.

Results

We enrolled a total of 728 women. Sixty-two percent had a University degree, 84% were employed and 77% were planning their first pregnancy.

Nearly 70% drank alcohol in any quantity; 16% were smokers; 6% was underweight; 21.4% was overweight; 51.6% did not assume folic acid; 22% was susceptible to rubella, 44.5% to hepatitis b and 13.2% to varicella.

According to the multivariate analysis, compared to women who already had at least one pregnancy, nulliparous women had a higher BMI [OR 1.60 (CI 1.02;2.48)] and were less likely to be susceptible to rubella [OR 0.33 (CI 0.20;0.58)] and to be consuming alcohol [OR 0.47 (CI 0.31;0.70)] or cigarettes [OR 0.48 (CI 0.26;0.90)].

Appropriate knowledge was associated with a correct behavior regarding smoking, drinking alcohol and folic acid supplementation.

Conclusions

This study shows that the prevalence of risk factors for APOs in our population is high.

Interventions aimed at reducing risk factors for APOs are needed and, to this purpose, a web intervention may represent a feasible tool to integrate tailored information and to inform preconception counseling targeting a specific group of women planning a pregnancy who are engaged on the web.

Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid: community-based randomized clinical trial in Italy and the Netherlands

BACKGROUND

In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.

METHODS/DESIGN

This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.

DISCUSSION

The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.

TRIAL REGISTRATION

Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161.

Folic acid supplementation and interpregnancy interval

BACKGROUND

Maternal folic acid supplementation between subsequent pregnancies may be important to reduce the risk of low folate status associated with short interpregnancy intervals. We examined how the prevalence of preconception folic acid use for a given pregnancy in Norwegian women varied according to the time interval from the previous pregnancy.

METHODS

Analysis was based on 48 855 pairs of pregnancies with the second pregnancy included in the Norwegian Mother and Child Cohort Study (birth years 1999-2009). Interpregnancy interval was defined as the time from birth of a child to the conception of the subsequent sibling. Preconception folic acid use was defined as any use of folic acid-containing supplements within the last 4 weeks before the second pregnancy.

RESULTS

The prevalence of preconception folic acid use was 31%. Among women with a term birth (≥37 weeks) in the previous pregnancy (92%), those with interpregnancy intervals ≤12 and ≥49 months were associated with up to 35% lower prevalence of preconception folic acid use for the second pregnancy, relative to the reference group (13-24 months). The low use in short intervals was mainly attributable to lower proportion of planned pregnancies and fewer women with higher education. Among women with a preterm birth (<37 weeks) in the previous pregnancy (8%), preconception folic acid use significantly decreased with increasing pregnancy spacing.

CONCLUSIONS

Our finding of a lower preconception folic acid use in women with both short and long interpregnancy intervals might help identifying those with higher risk of folate deficiency and preventing unwanted pregnancy outcomes.

A cohort study of a tailored web intervention for preconception care

Background

Preconception care may be an efficacious tool to reduce risk factors for adverse pregnancy outcomes that are associated with lifestyles and health status before pregnancy. We conducted a web-based cohort study in Italian women planning a pregnancy to assess whether a tailored web intervention may change knowledge and behaviours associated with risks for adverse pregnancy outcomes.

Methods

The study was entirely conducted on the web on a cohort of Italian women of childbearing age. Data collected at baseline on health status, lifestyles and knowledge of risk factors for adverse pregnancy outcomes were used for generating a tailored document including recommendations for folic acid supplementation, obesity and underweight, smoking, alcohol consumption, vaccinations, chronic and genetic diseases, exposure to medications. Prevalence of risk factors and knowledge was assessed 6 months after the intervention. Logistic regression models were used to explore the factors associated with risk factors after the intervention.

Results

Of the 508 enrolled women, 282 (55.5%) completed the study after 6 months since the delivery of tailored recommendations. At baseline, 48% of the participants took folic acid supplementation (95% CI 43.2; 51.9) and 69% consumed alcohol (95% CI 64.7; 72.9). At the follow up 71% of the participants had a preconception visit with a physician. Moreover we observed a decrease of alcohol consumption (−46.5% 95% CI −53.28; −38.75) and of the proportion of women not taking folic acid supplementation (−23.4% 95% CI −31.0; 15.36). We observed an improvement in knowledge of the information about the preconception behaviours to prevent adverse pregnancy outcomes (20.9% 95% CI 14.6%; 27.1%). Having a preconception visit during follow up was significally associated to an increase in folic acid supplementation (OR 2.53 95% CI 1.40; 4.60).

Conclusions

Our results suggest that a tailored web intervention may improve general preconception health in women planning a pregnancy. A web preconception intervention may be integrated with classic preconception care by health professionals. Clinical trials should be conducted to confirm these findings.

5,10-Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms: genotype frequency and association with homocysteine and folate levels in middle-southern Italian adults

Two genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene (C677T and A1298C) can influence the plasma homocysteine (Hcy) levels, especially in the presence of an inadequate folate status. The aim of this study was to evaluate the frequencies of C677T and of A1298C MTHFR polymorphisms and their correlation with Hcy and serum folate concentrations in a population of blood donors living in a region of middle-southern Italy (the Molise Region). One hundred ninety seven blood donors were studied for total plasma Hcy, serum folate and C677T and A1298C MTHFR genotypes. The frequency of C677T genotypes was 20.8% (CC), 49.8% (CT) and 29.4% (TT); for the A1298C genotypes: 48.7% (AA), 43.7% (AC) and 7.6% (CC). Hcy and serum folate concentrations were significantly different among genotypes of the C677T polymorphism (CC versus CT versus TT: <0.0001 both for Hcy and folate), with Hcy values increasing, and serum folate decreasing, from CC to TT subjects. Regarding to A1298C polymorphism, the difference among genotypes (AA versus AC versus CC; p: 0.026 for Hcy and 0.014 for serum folate), showed an opposite trend for both parameters, with Hcy higher in the wild-type and lower in the homozygotes and serum folate higher in CC than in AA subjects. In conclusion, we found a high frequency of MTHFR allele associated with high level of Hcy and low levels of folate in an Italian southern population.

Health promotion for children, mothers and families: here's why we should "think about it before conception"

About 90,000 preterm infants or babies with birth defects are born in Italy every year, nearly 250 per day. These congenital conditions and their outcomes represent the most important burden of disease affecting the health status and the quality of life during infancy, childhood and beyond. In many cases they are fostered by the presence of maternal and/or paternal preconception risk factors whose effects can be modified by primary prevention.

In the contemporary vision of maternal and child health, the traditional gap between preconception period and pregnancy is overcome through promotion of reproductive health and wellness in women, men and couples, regardless of their reproductive plans and possible future pregnancies. This paradigm should become the basic foundation to improve and protect infants’, children’s and adolescents’ health. Useful interventions belong to four broad areas: a) promotion of women’s and couples’ health in general, and protection from risk of adverse events in future pregnancies (if any); b) identification and treatment of conditions that increase the risk of adverse reproductive outcomes; c) help for women (couples) planning for pregnancy; d) identification of genetic risks, and help for independent and responsible decision making.

Pediatricians and neonatologists can effectively promote primary prevention in the interconception period, when parents seek consultation for their previous child, in adolescent medicine, in family health education, in socio-sanitary network, and in advocacy activities in favor of infants and children. These actions should be part of an operational framework including perinatal outreach programs, information campaigns, and focus on problems of high-risk women, children and families.

Birth defects in a national cohort of pregnant women with HIV infection in Italy, 2001-2011

OBJECTIVE

We used data from a national study of pregnant women with HIV to evaluate the prevalence of congenital abnormalities in newborns from women with HIV infection.

DESIGN

Observational study.

SETTING

University and hospital clinics.

POPULATION

Pregnant women with HIV exposed to antiretroviral treatment at any time during pregnancy.

METHODS

The total prevalence of birth defects was assessed on live births, stillbirths, and elective terminations for fetal anomaly. The associations between potentially predictive variables and the occurrence of birth defects were expressed as odds ratios (ORs) with 95% confidence intervals (95% CIs) for exposed versus unexposed cases, calculated in univariate and multivariate logistic regression analyses.

MAIN OUTCOME MEASURES

Birth defects, defined according to the Antiretroviral Pregnancy Registry criteria.

RESULTS

A total of 1257 pregnancies with exposure at any time to antiretroviral therapy were evaluated. Forty-two cases with major defects were observed. The total prevalence was 3.2% (95% CI 1.9-4.5) for exposure to any antiretroviral drug during the first trimester (23 cases with defects) and 3.4% (95% CI 1.9-4.9) for no antiretroviral exposure during the first trimester (19 cases). No associations were found between major birth defects and first-trimester exposure to any antiretroviral treatment (OR 0.94, 95% CI 0.51-1.75), main drug classes (nucleoside reverse transcriptase inhibitors, OR 0.95, 95% CI 0.51-1.76; non-nucleoside reverse transcriptase inhibitors, OR 1.20, 95% CI 0.56-2.55; protease inhibitors, OR 0.92, 95% CI 0.43-1.95), and individual drugs, including efavirenz (prevalence for efavirenz, 2.5%).

CONCLUSIONS

This study adds further support to the assumption that first-trimester exposure to antiretroviral treatment does not increase the risk of congenital abnormalities.

The global burden of congenital toxoplasmosis: a systematic review

OBJECTIVE

To estimate the global burden of congenital toxoplasmosis (CT), which results from infection of pregnant women with Toxoplasma gondii.

METHODS

The authors systematically searched 9 major databases for published and unpublished sources and established direct contact with the authors of source materials. Searches were country-specific. To be included, studies had to report on the incidence of CT, on positivity to Toxoplasma-specific IgM in infants and pregnant women (including seroconversion results) or on positivity to Toxoplasma-specific IgG in the general population. Various modelling techniques were used, depending on the country-specific data available, to estimate the CT incidence and burden in each country. These data were then synthesized into an estimate of the global incidence of CT and of the global burden of CT in disability-adjusted life years (DALYs).

FINDINGS

The global annual incidence of congenital toxoplasmosis was estimated to be 190,100 cases (95% credible interval, CI: 179,300-206,300). This was equivalent to a burden of 1.20 million DALYs (95% CI: 0.76-1.90). High burdens were seen in South America and in some Middle Eastern and low-income countries.

CONCLUSION

Congenital toxoplasmosis poses a substantial burden of poor health globally. Toxoplasmosis should be included in future updates of the global burden of disease and the corresponding data should be used to support public health interventions to reduce disease burden.

Folate, vitamin B12 and homocysteine status in an Italian blood donor population

BACKGROUND AND AIMS

The relevance of folate, other B-vitamins and homocysteine (Hcy) for the occurrence or prevention of several diseases has induced growing interest. Unfortunately, little evidence is available regarding B-vitamin concentrations in Italy. This study evaluated in a region of middle-southern Italy, folate, vitamin B12 and Hcy concentrations and the prevalence of their ideal blood levels. The main determinants of B-vitamins and Hcy were also considered.

METHODS AND RESULTS

Male and female blood donors (n=240), aged 18-66 years and living in Molise region (Italy), were enrolled in the study. They completed a brief questionnaire concerning fruit and vegetables intake, physical activity and smoking; serum and red blood cell (RBC) folate and serum vitamin B12 were measured by an immunoassay on an automated analyzer. Total Hcy was measured by high performance liquid chromatography (HPLC). Geometric means of serum folate, RBC folate and serum vitamin B12 were 10.8nmoll(-1), 426.0nmoll(-1) and 245.0pmoll(-1), respectively. Only 22.5%, 24.2% and 16.3% of blood donors showed an adequate level of serum folate, RBC folate or serum vitamin B12 respectively. When a cut-off of RBC folate ≥906nmoll(-1) was used no women of childbearing age had adequate levels. A geometric mean of 14.0μmoll(-1) was found for total Hcy, with an ideal concentration in 12.1% of subjects. Folate concentration was higher in women and non-smokers and in subjects with higher consumption of fruit and vegetable.

CONCLUSION

This study shows a low-moderate B-vitamins status in middle-southern Italy, associated with an inadequate fruit and vegetable consumption. A public health strategy should be undertaken to encourage a B-vitamin-rich diet with the addition of vitamin supplements or vitamin fortified foods in population subgroups with special needs.

Malformation surveillance and maternal drug exposure: the MADRE project

A project implemented within the framework of the International Clearinghouse for Birth Defect Monitoring Systems is named MADRE: MAlformation DRug Exposure surveillance. The idea is to survey the simultaneous occurrence of malformations and first-trimester drug exposures. In a 2-year period 1990-91, this has yielded 1448 infants known to have been exposed to drugs and that are known to have malformations. Cases have been reported by eight programs: Australia, Central-East France, Israel, Italy IPIMC, Italy IMER, Japan Red Cross Hospitals, Japan Maternal Health and Welfare, and South America. By searching this databank for associations between drugs and malformations, specific relationships can be detected.The 9th revision of the WHO International Classification of Diseases, adapted by the British Paediatric Association, known as ICD9/BPA is used for coding malformations. This is a hierarchical system with 5 digits as the maximum level of specification of each malformation.The ATC (Anatomical Therapeutic Chemical) classifications system is used for coding drugs. This is a multiple level, hierarchical classification with up to 7 digits for specifying each drug.Up to five drugs and malformations are coded for each case using ATC and ICD9/BPA classifications, and all observed drug-malformation pairs form the basis for the analysis. For each drug-malformation combination where three or more cases are observed, a set of 2×2 tables is formed and analyzed as in case-control studies. The odds ratio for the pair, stratified for program, gives the relative risk for the malformation in question, comparing use of the specific drug with all other drugs.Well known or controversial associations were tested in the collected material, and at this stage only one new association is suggested, that is between cardiac defects and maternal treatment with thyroid hormones. This finding has to be further explored with new data.

Hormone therapy during pregnancy and isolated hypospadias: an international case-control study

Mothers of boys with hypospadias and control mothers were interviewed in eight malformation monitoring programs around the world. Hormone therapy was used quite frequently in five but rarely in three of the programs. The odds ratio for hypospadias after hormone therapy during pregnancy was 2.8 (95% confidence limits 1.2, 6.9) but there was no correlation between the timing of hormone therapy and the location of the urethral orifice, nor between the severity of the malformation and hormone therapy. Programs with the highest hormone exposure rate showed the lowest odds ratio for pregnancy bleeding, the most common reason for hormone therapy. These latter findings cast doubts on the causal association between hormone therapy and isolated hypospadias. Alternative explanations are recall or interviewer bias or unidentified confounders.

Does googling for preconception care result in information consistent with international guidelines: a comparison of information found by Italian women of childbearing age and health professionals

Background

Preconception counseling is effective in reducing the risk of adverse pregnancy outcomes. The Internet is commonly used by women and health professionals to search for health information. We compared the consistency of preconception information found on the Internet with the recommendations published by American Journal of Obstetrics and Gynecology (AJOG) simulating a web search by women of childbearing age and health professionals.

Methods

We reviewed websites resulting from a Google search performed using search strings selected by Italian women of childbearing age and health professionals. We investigated if retrieved information was consistent with AJOG recommendations for preconception care. Logistic regression was used to compare presence of consistent recommendations between women and health professionals.

Results

The highest frequency of correct recommendations was found for folic acid supplementation (39.4% of websites). Consistency of preconception information did not significantly differ between search strategies except for folic acid supplementation. “Communities and blogs” website category provided less frequently correct recommendations compared with “Medical/Public Agency" category (i.e. folic acid supplementation (aOR 0.254; CI 0.098-0.664; p = <0.01). Commercial links, found in 60% of websites, were associated with presence of correct recommendations excepting few items (i.e. physical exercise (aOR 1.127; CI 0.331-3.840; p = 0.848).

Conclusions

Preconception information found is poor and inaccurate regardless of the search is performed by women or health professionals. It is unlikely that information found on the web have any positive impact among women and health professionals in our setting. Strategies to improve preconception information on the web and education of health professionals for web searching of health information should be considered.

Methodological approaches to evaluate teratogenic risk using birth defect registries: advantages and disadvantages

Background

Different approaches have been used in case-control studies to estimate maternal exposure to medications and the risk of birth defects. However, the performance of these approaches and how they affect the odds ratio (OR) estimates have not been evaluated using birth-defect surveillance programmes. The aim of this study was to evaluate the scope and limitations of three case-control approaches to assess the teratogenic risk of birth defects in mothers exposed to antiepileptic medications, insulin, or acetaminophen.

Methodology/Principal Findings

We studied 110,814 non-malformed newborns and 58,514 live newborns with birth defects registered by the Latin American Collaborative Study of Congenital Anomalies (ECLAMC) between 1967 and 2008. Four controls were randomly selected for each case in the same hospital and period, and three different control groups were used: non-malformed newborns (HEALTHY), malformed newborns (SICK), and a subgroup of SICK, only-exposed cases (OECA). Associations were evaluated using OR and Pearson's chi-square (P<0.01). There were no concordance correlations between the HEALTHY and OECA designs, and the average OR differences ranged from 3.0 to 11.5 for the three evaluated medicines. The overestimations observed for HEALTHY design were increased as higher OR values were given, with a high and statistically significant correlation between the difference and the mean. On the contrary, the concordance correlations obtained between the SICK and OECA designs were quite good, with no significant differences in the average risks.

Conclusions

The HEALTHY design estimates the true population OR, but shows a high rate of false-positive results presumably caused by differential misclassification bias. This bias decreases with the increase of the proportion of exposed controls. SICK and OECA odds ratios cannot be considered a direct estimate of the true population OR except under certain conditions. However, the SICK and OECA designs could provide practical information to generate hypotheses about potential teratogens.

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. Birth Defects Research (Part A), 2012.

Phocomelia: a worldwide descriptive epidemiologic study in a large series of cases from the International Clearinghouse for Birth Defects Surveillance and Research, and overview of the literature

Epidemiologic data on phocomelia are scarce. This study presents an epidemiologic analysis of the largest series of phocomelia cases known to date. Data were provided by 19 birth defect surveillance programs, all members of the International Clearinghouse for Birth Defects Surveillance and Research. Depending on the program, data corresponded to a period from 1968 through 2006. A total of 22,740,933 live births, stillbirths and, for some programs, elective terminations of pregnancy for fetal anomaly (ETOPFA) were monitored. After a detailed review of clinical data, only true phocomelia cases were included. Descriptive data are presented and additional analyses compared isolated cases with those with multiple congenital anomalies (MCA), excluding syndromes. We also briefly compared congenital anomalies associated with nonsyndromic phocomelia with those presented with amelia, another rare severe congenital limb defect. A total of 141 phocomelia cases registered gave an overall total prevalence of 0.62 per 100,000 births (95% confidence interval: 0.52-0.73). Three programs (Australia Victoria, South America ECLAMC, Italy North East) had significantly different prevalence estimates. Most cases (53.2%) had isolated phocomelia, while 9.9% had syndromes. Most nonsyndromic cases were monomelic (55.9%), with an excess of left (64.9%) and upper limb (64.9%) involvement. Most nonsyndromic cases (66.9%) were live births; most isolated cases (57.9%) weighed more than 2,499 g; most MCA (60.7%) weighed less than 2,500 g, and were more likely stillbirths (30.8%) or ETOPFA (15.4%) than isolated cases. The most common associated defects were musculoskeletal, cardiac, and intestinal. Epidemiological differences between phocomelia and amelia highlighted possible differences in their causes.

Cyclopia: an epidemiologic study in a large dataset from the International Clearinghouse of Birth Defects Surveillance and Research

Cyclopia is characterized by the presence of a single eye, with varying degrees of doubling of the intrinsic ocular structures, located in the middle of the face. It is the severest facial expression of the holoprosencephaly (HPE) spectrum. This study describes the prevalence, associated malformations, and maternal characteristics among cases with cyclopia. Data originated in 20 Clearinghouse (ICBDSR) affiliated birth defect surveillance systems, reported according to a single pre-established protocol. A total of 257 infants with cyclopia were identified. Overall prevalence was 1 in 100,000 births (95%CI: 0.89-1.14), with only one program being out of range. Across sites, there was no correlation between cyclopia prevalence and number of births (r = 0.08; P = 0.75) or proportion of elective termination of pregnancy (r = -0.01; P = 0.97). The higher prevalence of cyclopia among older mothers (older than 34) was not statistically significant. The majority of cases were liveborn (122/200; 61%) and females predominated (male/total: 42%). A substantial proportion of cyclopias (31%) were caused by chromosomal anomalies, mainly trisomy 13. Another 31% of the cases of cyclopias were associated with defects not typically related to HPE, with more hydrocephalus, heterotaxia defects, neural tube defects, and preaxial reduction defects than the chromosomal group, suggesting the presence of ciliopathies or other unrecognized syndromes. Cyclopia is a very rare defect without much variability in prevalence by geographic location. The heterogeneous etiology with a high prevalence of chromosomal abnormalities, and female predominance in HPE, were confirmed, but no effect of increased maternal age or association with twinning was observed.

Very rare defects: what can we learn?

The International Clearinghouse for Birth Defects Surveillance and Research conducted a study on very rare defects (VRDs) to test methodologies in their population surveillance and to increase the knowledge of their epidemiology. Eight VRDs: acardia (AC), amelia (AM), bladder exstrophy (BE), cloaca exstrophy (CE), conjoined twins (CT), cyclopia (CY), "true" phocomelia (PH), and sirenomelia (SI) were selected, all of whom showed prevalences in the order of 1/100,000 births, except for BE: 1/48,000 births. Materials in this investigation from 25 million pregnancy outcomes, were provided by 22 Clearinghouse-member programs. The study protocol provided a working definition, a summary of the phenotypic characteristic, and a list of ICD-9 and ICD-10 codes for each VRDs. Learned lessons include: (1) The suspected associations of decreasing risk with advancing maternal age in AM and SI, and increasing risk in BE, and increasing frequency of twins in SI, were confirmed. (2) Morphologically similar defects showed dissimilar epidemiological characteristics, namely, AM and PH, and BE and CE. (3) Heterogeneity in total prevalences for most VRDs among different surveillance programs were attributed to operational reasons, except for SI and CT in which Amerindian ethnicity seems to be associated with higher prevalence. (4) Verbatim description is essential and must be stored in electronic files. In addition to codes. (5) Dysmorphologists or clinical geneticists are an essential part of the coordinating team of the surveillance program. (6) ICD coding system is insufficient. (7) Surveillance programs should be a valuable source of information on exposures to risk factors during pregnancy.

Sirenomelia: an epidemiologic study in a large dataset from the International Clearinghouse of Birth Defects Surveillance and Research, and literature review

Sirenomelia is a very rare limb anomaly in which the normally paired lower limbs are replaced by a single midline limb. This study describes the prevalence, associated malformations, and maternal characteristics among cases with sirenomelia. Data originated from 19 birth defect surveillance system members of the International Clearinghouse for Birth Defects Surveillance and Research, and were reported according to a single pre-established protocol. Cases were clinically evaluated locally and reviewed centrally. A total of 249 cases with sirenomelia were identified among 25,290,172 births, for a prevalence of 0.98 per 100,000, with higher prevalence in the Mexican registry. An increase of sirenomelia prevalence with maternal age less than 20 years was statistically significant. The proportion of twinning was 9%, higher than the 1% expected. Sex was ambiguous in 47% of cases, and no different from expectation in the rest. The proportion of cases born alive, premature, and weighting less than 2,500 g were 47%, 71.2%, and 88.2%, respectively. Half of the cases with sirenomelia also presented with genital, large bowel, and urinary defects. About 10-15% of the cases had lower spinal column defects, single or anomalous umbilical artery, upper limb, cardiac, and central nervous system defects. There was a greater than expected association of sirenomelia with other very rare defects such as bladder exstrophy, cyclopia/holoprosencephaly, and acardia-acephalus. The application of the new biological network analysis approach, including molecular results, to these associated very rare diseases is suggested for future studies.

Conjoined twins: a worldwide collaborative epidemiological study of the International Clearinghouse for Birth Defects Surveillance and Research

Conjoined twins (CT) are a very rare developmental accident of uncertain etiology. Prevalence has been previously estimated to be 1 in 50,000 to 1 in 100,000 births. The process by which monozygotic twins do not fully separate but form CT is not well understood. The purpose of the present study was to analyze diverse epidemiological aspects of CT, including the different variables listed in the Introduction Section of this issue of the Journal. The study was made possible using the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) structure. This multicenter worldwide research includes the largest sample of CT ever studied. A total of 383 carefully reviewed sets of CT obtained from 26,138,837 births reported by 21 Clearinghouse Surveillance Programs (SP) were included in the analysis. Total prevalence was 1.47 per 100,000 births (95% CI: 1.32-1.62). Salient findings including an evident variation in prevalence among SPs: a marked variation in the type of pregnancy outcome, a similarity in the proportion of CT types among programs: a significant female predominance in CT: particularly of the thoracopagus type and a significant male predominance in parapagus and parasitic types: significant differences in prevalence by ethnicity and an apparent increasing prevalence trend in South American countries. No genetic, environmental or demographic significant associated factors were identified. Further work in epidemiology and molecular research is necessary to understand the etiology and pathogenesis involved in the development of this fascinating phenomenon of nature.