Maternal vitamin B ₁₂ deficiency and perinatal outcomes in southern India

Abstract

Background

Vitamin B ₁₂ deficiency during pregnancy has been associated with adverse maternal and infant health outcomes. Few prospective studies have investigated vitamin B ₁₂ status early in pregnancy, and its links to infant vitamin B ₁₂ status, particularly in India where the burden of vitamin B ₁₂ deficiency is estimated to be the highest globally. The objective of this study was to examine the associations of maternal vitamin B ₁₂ biomarkers with neonatal vitamin B ₁₂ status.

Methods

Pregnant women (~12 weeks’ gestation) were enrolled in a perinatal cohort study in Bangalore, India. Total vitamin B ₁₂, methylmalonic acid (MMA), and homocysteine concentrations were evaluated in maternal samples at enrollment and in neonates at birth using cord blood. Linear and binomial regression models were used to evaluate the associations of maternal vitamin B ₁₂ biomarkers with neonatal vitamin B ₁₂ status and perinatal outcomes.

Results

A total of 63.2% of women had vitamin B ₁₂ deficiency (<148 pmol/L), 87.2% had vitamin B ₁₂ insufficiency (<221 pmol/L), and 47.3% had impaired vitamin B ₁₂ status (vitamin B ₁₂<148 pmol/L and MMA>0.26μmol/L) at enrollment; 40.8% of neonates had vitamin B ₁₂ deficiency, 65.6% were insufficiency, and 38.1% had impaired vitamin B ₁₂ status at birth. Higher maternal vitamin B ₁₂ concentrations at enrollment were associated with increased neonatal vitamin B ₁₂ concentrations (β(SE): 0.40 (0.05); p<0.0001) and lower risk of neonatal vitamin B ₁₂ deficiency (Risk Ratio [RR]: 0.53; 95% CI: [0.43, 0.65]; p<0.0001). Maternal vitamin B ₁₂ deficiency (RR: 1.97 [1.43, 2.71]; p<0.001), insufficiency (RR: 2.18 [1.23, 3.85]; p = 0.007), and impaired vitamin B ₁₂ status (RR: 1.49 [1.13, 1.97]; p = 0.005) predicted a two-fold increase in the risk of neonatal vitamin B ₁₂ deficiency at birth.

Conclusions

The prevalence of vitamin B ₁₂ deficiency was high early in pregnancy and predicted neonatal vitamin B ₁₂ status. Future research is needed to determine the role of vitamin B ₁₂ in the development of pregnancy and infant outcomes, and to inform screening and interventions to improve maternal and child health.