Prevention of neural tube defects with folic acid: Prevalence, risk factors, folic acid supplementation, and recommendations for the government

Abstract

 Neural tube defects（NTDs）comprising myelomeningocele and anencephaly were proven to be folic acid- preventable in the United Kingdom in 1991. The Ministry of Health and Welfare recommended in 2000 that women planning to conceive should take folic acid supplements 0.4 mg a day from a month before to three months after conception in order to reduce the risk of NTDs in the fetus. The Japan Association of Obstetricians and Gynecologists（JAOG）reported that the prevalence of myelomeningocele has remained unchanged while that of anencephaly has significantly decreased over the past 20 years, where the number of fetuses terminated because of NTDs in the first trimester has not been counted. Subsequently, we attempted to correct the prevalence of NTDs from 2016 to 2018 based on data supplied from 536 hospitals by incorporating the number of above fetuses terminated, which varied from 7.93 to 8.82/10,000 deliveries and was 1.5-fold higher than that of JAOG. Furthermore, the clinical effects of folic acid on the occurrence or recurrence of NTDs, risk factors of NTDs, and awareness and intake of supplements will be analyzed and discussed. We believe that the Japanese government should implement the fortification of grains with folic acid soon, which will certainly decrease the number of fetuses afflicted with NTDs.