Prevalence and time trends of neural tube defects in regions of the Russian Federation

Neural tube defects – a group of severe congenital malformations with a high level of mortality, childhood disability. The average prevalence of these defects is approximately 1 per 1000 births. The main measures to reduce the prevalence of neural tube defects are primary and secondary prevention measures, the effectiveness of which can be determined by congenital malformations monitoring.Research purpose. To determine the prevalence of neural tube defects, as well as trends in their prevalence for 2011 to 2017 in the Russian Federation according to monitoring of congenital malformations.Results. The total prevalence of anencephaly among newborns and fetuses was 4.63 (95% confidence interval - CI 4.40–4.88) per 10000 births, spina bifida – 6.18 (95% CI 5.91–6.46) and encephalocele 1.34 (95% CI 1.21–1.47). At the same time, the prevalence of anencephaly only among live births was 0.11 (95% CI 0.08–0.15) per 10000, spina bifida – 2.24 (95% CI 2.08–2.41) and encephalocele – 0 25 (95% CI 0.20–0.31). The decrease in prevalence of birth defects among live births compared with the total prevalence is provided by a high level of detection of these defects by ultrasound examination during pregnancy with the subsequent elimination of the affected fetuses. The maximum proportion of eliminated fetuses is observed for anencephaly (90.5%), for encephalocele the proportion of aborted fetuses is 77.4% and for spina bifida – 59.3%. Over the 7-year period, the multidirectional prevalence trends were noted: the increasing trend for total prevalence of neural tube defects and the decreasing trend for prevalence of these defects among live-born children.Conclusion. Estimates of the prevalence of neural tube defects in Russian Federation regions are obtained. The dynamics of the studied defects prevalence indicates that the decreasing of neural tube defects prevalence among live births is associated with secondary prevention measures