Association of Neural Tube Defects with maternal and neonatal serum vitamin B12 level in Bangladesh: A multicenter case control study

Background: Neural tube defects (NTDs), a congenital deformity of the central nervous system attributed to multifactorial etiology including nutritional factors e.g., folic acid deficiency. Some studies suggested deficiency of vitamin B12 may be another factor behind NTDs due to its intimate metabolic pathway with folic acid. This study aimed to identify the association of NTDs with maternal and neonatal serum vitamin B12 level.Methods: This case-control study was conducted from January 2014 to June 2015 in three tertiary level hospitals at Dhaka, Bangladesh. 32 cases (neonate with NTDs-mother pair) were selected from Bangabandhu Sheikh Mujib Medical University (BSMMU) Hospital (18), Dhaka Medical College Hospital (8) and Sir Salimullah Medical College and Mitford hospital (6). 40 age and sex matched controls were selected from BSMMU. A baseline assessment of the mothers on age, parity, education, residence, antenatal checkup, method of delivery and socio-economic status was taken. Vitamin B12 was estimated from the venous blood sample of the mother and newborn within 7 days after delivery. We considered <200 pg/ml of vitamin B12 as ‘deficiency’, 200-300 pg/ml as ‘marginal deficiency’ and >300 pg/ml as ‘normal’. Quantitative data were expressed as mean ± SD and qualitative data were expressed as proportion. Chi-square test and student’s unpaired t-test was used for comparison of categorical and continuous variables respectively. Pearson correlation was used to determine the correlation between continuous variables.Result: Mothers with low socio-economic status (p=0.004) and irregular antenatal checkup (p=0.029) were significantly higher among the cases. Serum vitamin B12 level of mother (p<0.01) and newborn (p<0.01) were significantly lower among the cases. Vitamin B12 deficient newborn were significantly higher among the cases (50% vs. 25%). Maternal and neonatal serum vitamin B12 levels were positively correlated with both case (Pearson R=0.517) and control (Pearson R=0.627) groups.Conclusion: This study finding suggests that both maternal and neonatal low serum vitamin B12 level is associated with NTDs. Vitamin B12 supplementation along with folic acid may be considered for to-be-mothers to prevent NTDs.