This study examines trends and geographical differences in total and live birth prevalence of trisomies 21, 18 and 13 with regard to increasing maternal age and prenatal diagnosis in Europe. Twenty-one population-based EUROCAT registries covering 6.1 million births between 1990 and 2009 participated. Trisomy cases included live births, fetal deaths from 20 weeks gestational age and terminations of pregnancy for fetal anomaly. We present correction to 20 weeks gestational age (ie, correcting early terminations for the probability of fetal survival to 20 weeks) to allow for artefactual screening-related differences in total prevalence. Poisson regression was used. The proportion of births in the population to mothers aged 35+ years in the participating registries increased from 13% in 1990 to 19% in 2009. Total prevalence per 10 000 births was 22.0 (95% CI 21.7–22.4) for trisomy 21, 5.0 (95% CI 4.8–5.1) for trisomy 18 and 2.0 (95% CI 1.9–2.2) for trisomy 13; live birth prevalence was 11.2 (95% CI 10.9–11.5) for trisomy 21, 1.04 (95% CI 0.96–1.12) for trisomy 18 and 0.48 (95% CI 0.43–0.54) for trisomy 13. There was an increase in total and total corrected prevalence of all three trisomies over time, mainly explained by increasing maternal age. Live birth prevalence remained stable over time. For trisomy 21, there was a three-fold variation in live birth prevalence between countries. The rise in maternal age has led to an increase in the number of trisomy-affected pregnancies in Europe. Live birth prevalence has remained stable overall. Differences in prenatal screening and termination between countries lead to wide variation in live birth prevalence.

Introduction Published prevalence rates of congenital diaphragmatic hernia (CDH) vary. This study aims to describe the epidemiology of CDH using data from high-quality, population-based registers belonging to the European Surveillance of Congenital Anomalies (EUROCAT). Methods Cases of CDH delivered between 1980 and 2009 notified to 31 EUROCAT registers formed the population-based case series. Prevalence over time was estimated using multilevel Poisson regression, and heterogeneity between registers was evaluated from the random component of the intercept. Results There were 3373 CDH cases reported among 12 155 491 registered births. Of 3131 singleton cases, 353 (10.4%) were associated with a chromosomal anomaly, genetic syndrome or microdeletion, 784 (28.2%) were associated with other major structural anomalies. The male to female ratio of CDH cases overall was 1:0.69. Total prevalence was 2.3 (95% CI 2.2 to 2.4) per 10 000 births and 1.6 (95% CI 1.6 to 1.7) for isolated CDH cases. There was a small but significant increase (relative risk (per year)=1.01, 95% credible interval 1.00–1.01; p=0.030) in the prevalence of total CDH over time but there was no significant increase for isolated cases (ie, CDH cases that did not occur with any other congenital anomaly). There was significant variation in total and isolated CDH prevalence between registers. The proportion of cases that survived to 1 week was 69.3% (1392 cases) for total CDH cases and 72.7% (1107) for isolated cases. Conclusions This large population-based study found an increase in total CDH prevalence over time. CDH prevalence also varied significantly according to geographical location. No significant association was found with maternal age.

Objective. To examine population-based overall and malformation-specific trends in the prenatal diagnosis, pregnancy termination, and perinatal mortality for congenital heart disease (CHD) during a period of rapid progress in prenatal diagnosis and medical management of CHD and to explore the impact of prenatal diagnosis on early neonatal mortality for specific (isolated) cardiac malformations. Methods. A total of 1982 cases of CHD, which were not associated with a known chromosomal anomaly, were obtained from the Paris Registry of Congenital Malformations. Main outcome measures were trends in the proportions diagnosed and terminated before birth, stillbirth, and early (<1 day, 1-week) neonatal mortality for (1) all cases; (2) all cases excluding isolated ventricular septal defects; and (3) malformation-specific trends for transposition of great arteries, hypoplastic left heart syndrome, coarctation of aorta, and tetralogy of Fallot. Analyses included cusum and binomial regression models for analysis of the trends during 1983–2000. Results. Prenatal diagnosis rates for CHD increased from 23.0% (95% confidence interval [CI]: 19.0–27.4) in 1983–1988 to 47.3% (95% CI: 43.8–50.8) in 1995–2000. Termination rates increased between 1983 and 1989 (9.9%; 95% CI: 7.2–13.2) and 1989 and 1994 (14.7%; 95% CI: 12.3–17.4) but seemed to remain stable thereafter. Other than for hypoplastic left heart syndrome, pregnancy termination was exceptional for the other 3 specific malformations examined. Early neonatal mortality decreased to less than one third in the period 1995–2000 as compared with 1983–1989 (risk ratio, first-week mortality: 0.31; 95% CI: 0.18–0.53). First-week mortality was significantly lower for cases of transposition of great arteries that were diagnosed before birth (risk difference: 15.4%; 95% CI: 4.0–26.7). Conclusions. Progress in clinical management, together with policies for increased access to prenatal diagnosis, has resulted in both a substantial increase in the prenatal diagnosis and considerable reductions in early neonatal mortality of CHD in the Parisian population.

Objective To assess the prevalence, timing of diagnosis and infant mortality of congenital heart defects (CHD) with population-based data and using a classification that allows regrouping of the International Paediatric and Congenital Cardiac Code into a manageable number of categories based on anatomic and clinical criteria (ACC-CHD). Design Population-based cohort study. Setting Greater Paris. Patients All cases (live births, terminations of pregnancy for foetal anomaly (TOPFA), foetal deaths) diagnosed prenatally, or up to 1 year of age in the birth cohorts, May 2005–April 2008, for women in Greater Paris (n=317 538 births). Diagnoses were confirmed in specialised centres and subsequently coded and classified into the categories of ACC-CHD by paediatric cardiologists in the study group. Results The total number of CHD was 2867, including 2348 live births (82%), 466 TOPFA (16.2%) and 53 foetal deaths (1.8%). The total prevalence of CHD was 90 per 10 000. After exclusion of ventricular septal defects (VSD), 40% of ‘isolated’ CHD was diagnosed prenatally with about one half of the remaining diagnosed before 7 days of age. Nevertheless, one in five cases of these major CHD was diagnosed after the fourth week. Infant mortality of ‘isolated’ CHD-VSD excluded was 8.5% with 40% of deaths occurring after the fourth week of life. These outcomes varied substantially across categories of ACC-CHD. Conclusions Timing of diagnosis, TOPFA, risk and timing of infant mortality were highly variable across the categories of CHD in ACC-CHD, suggesting that it may be a useful measure of severity, and hence, predictor of outcomes of CHD.

Study question What are the long term trends in the total (live births, fetal deaths, and terminations of pregnancy for fetal anomaly) and live birth prevalence of neural tube defects (NTD) in Europe, where many countries have issued recommendations for folic acid supplementation but a policy for mandatory folic acid fortification of food does not exist? Methods This was a population based, observational study using data on 11 353 cases of NTD not associated with chromosomal anomalies, including 4162 cases of anencephaly and 5776 cases of spina bifida from 28 EUROCAT (European Surveillance of Congenital Anomalies) registries covering approximately 12.5 million births in 19 countries between 1991 and 2011. The main outcome measures were total and live birth prevalence of NTD, as well as anencephaly and spina bifida, with time trends analysed using random effects Poisson regression models to account for heterogeneities across registries and splines to model non-linear time trends. Summary answer and limitations Overall, the pooled total prevalence of NTD during the study period was 9.1 per 10 000 births. Prevalence of NTD fluctuated slightly but without an obvious downward trend, with the final estimate of the pooled total prevalence of NTD in 2011 similar to that in 1991. Estimates from Poisson models that took registry heterogeneities into account showed an annual increase of 4% (prevalence ratio 1.04, 95% confidence interval 1.01 to 1.07) in 1995-99 and a decrease of 3% per year in 1999-2003 (0.97, 0.95 to 0.99), with stable rates thereafter. The trend patterns for anencephaly and spina bifida were similar, but neither anomaly decreased substantially over time. The live birth prevalence of NTD generally decreased, especially for anencephaly. Registration problems or other data artefacts cannot be excluded as a partial explanation of the observed trends (or lack thereof) in the prevalence of NTD. What this study adds In the absence of mandatory fortification, the prevalence of NTD has not decreased in Europe despite longstanding recommendations aimed at promoting peri-conceptional folic acid supplementation and existence of voluntary folic acid fortification. Funding, competing interests, data sharing The study was funded by the European Public Health Commission, EUROCAT Joint Action 2011-2013. HD and ML received support from the European Commission DG Sanco during the conduct of this study. No additional data available.