Neural Tube Defects (NTDs) are considered to be one of the commonest congenital birth defects. These are caused by partial or complete failure of the fetal neural tube to close at or around day 28 of gestation and this results in different malformations that range from spina bifida to anencephaly. Multiple studies have demonstrated that ensuring adequate intake of folate before conception and for the first four weeks is important in reducing the incidence of NTDs by up to 50%, and this is the reason that prenatal vitamins all contain folic acid or folate.

Since the introduction of food fortification with folic acid, the incidence of NTDs has decreased significantly, but has not been eliminated in the countries that fortify. Researches performed a meta-analysis of 32 studies involving 1,890 mothers who gave birth to babies with NTD malformations to understand whether they could determine if there was a relationship between markers of Single Carbon metabolism and NTD.

What they found was that mothers who had low folate and vitamin B12 levels had a significantly higher risk delivering a child with an NTDs, when measured early in pregnancy and recommend that folate and B12 be given in the peri-conception period to be a more effective preventative measure to reduce the incidence of this very distressing birth defect, even further.