Long term trends in prevalence of neural tube defects in Europe: population based study

Abstract

Study queStionWhat 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? MethodSThis 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 liMitationSOverall, 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 addSIn 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.

The Prevalence, Trend, and Associated Demographic Factors of Neural Tube Defects at Orotta National Referral Maternity Hospital, Asmara: Retrospective Record Review Study

“…A study that was conducted in Europe by Khoshnood (2015), documented a total prevalence of 0.91 per 10 000 for 1991-2011 and 0.85 per 10 000 in the period 2003-07 which is very low as compared to the results of this study [7]. This high prevalence can be argued that as in Eritrea, even though there is folic acid supplementation, it is only during pregnancy as well as absence of folic acid fortification on foods can lead to this high prevalence of NTD [8].…”

How I treat anemia in pregnancy: iron, cobalamin, and folate

“…85 By contrast, Khoshnood et al, in an observational study of 11 353 cases of NTD in ;12.5 million births in 19 countries in Europe, showed no change in prevalence of NTDs between 1991 and 2011, despite longstanding recommendations promoting folic acid supplementation and the existence of voluntary folic acid fortification. 86 Absent mandatory fortification, the prevalence of NTD in Europe has remained unchanged.…”

British Association for Psychopharmacology consensus guidance on the use of psychotropic medication preconception, in pregnancy and postpartum 2017

“…Significant associations have been reported for spina bifida (an approximate 13-fold increased risk from approximately 0.09% in the general population (Khoshnood et al, 2015) to between 1 and 2%), atrial septal defects, cleft palate, hypospadias, polydactyly and craniosynostosis (Jentink et al, 2010b). Although teratogenicity may depend on daily valproate dosage, the reported critical thresholds vary widely (Tomson and Battino, 2012).…”