Maternal Vitamin B12 and the Risk of Fetal Neural Tube Defects

Folic acid insufficiency is a known risk factor for neural tube defects (NTDs), while the role of vitamin B12 is questionable. Thus, our purpose was to investigate if low maternal serum vitamin B12 is associated with an increased risk of NTDs. Prenatal Diagnosis and Clinical Genetics Clinics, National Research Center, in collaboration with the Radioisotope Department, Nuclear Research Cent- er. The study groups included 36 wo- men who were, or had been, pregnant with a NTD-affected fetus. The control groups comprised 35 healthy women with normal prior or current pregnancy and uncomplicated obstetric histories. Fasting plasma homocysteine, serum folate and cobalamin (vitamin B12) were performed. Odds ratio (OR) and 95% confidence intervals were cal- culated. The fasting homocysteine was significantly higher in the study groups as compared to the controls. The median serum folate concentrations were similar in cases and controls. While the median vitamin B12 con- centrations were significantly lower in the study groups compared to the controls. Low vitamin B12 con- centration was associated with an approximately 2 to 3 fold increased risk for NTDs. Low maternal serum of vitamin B12 can be considered an important etiologic factor for the development of neural tube defects in our population. This may help in both genetic counseling for families with history of NTDs malformation, and as a precon- ceptional prophylactic measure by maternal supplementation of vitamin B12 and folic acid.