Impact of maternal hypovitaminosis D on birth and neonatal outcome - a prospective cohort study

Vitamin D deficiency in pregnant women is of special concern as mother is the only source of vitamin D for the developing fetus, and maternal hypovitaminosis D has been implicated in a number of maternal and neonatal adverse outcomes. The objective of this study was to assess the association of maternal circulating 25-hydroxy vitamin D3 [25(OH)D] concentration with cord blood 25(OH)D and adverse birth and neonatal outcomes.

This prospective cohort study was conducted in Mahatma Gandhi Medical College and Research Institute (MGMCRI) from January 2020 to December 2020. 121 babies born to mothers with singleton pregnancy tested for serum 25(OH)D level on admission for safe confinement were included in the study and cord blood of the babies were sampled for 25(OH)D. Based on the maternal 25(OH)D level, babies were categorized as those born to mothers with sufficient vitamin D level and those born to mothers with hypovitaminosis D (deficient/insufficient) and primary and secondary outcome was compared between two groups.

Maternal and cord blood hypovitaminosis D was observed in 65% of mothers and 68.6% of babies, respectively. Maternal vitamin D level was the single most significant predictor of cord blood vitamin D level with five-fold increased risk of cord blood hypovitaminosis D in babies born to mothers with hypovitaminosis D. Birthweight (t = -2.219, p = .028) and preterm birth (aOR = 4.417, 95% CI: 1.03-18.9) was significantly associated with maternal hypovitaminosis D and a trend toward increased risk of LBW (aOR - 2.1, 95%CI: 0.6-7.3), SGA babies (aOR - 1.5, 95% CI: 0.5-4.7), perinatal depression (aOR - 1.5, 95% CI: 0.4-5.8) and neonatal hyperbilirubinemia (aOR = 2.68, 95%CI: 0.942-7.6) was observed.

Hypovitaminosis D in pregnant women is a significant health issue affecting both the mother and her baby. Safest dose for supplementation during pregnancy to prevent adverse perinatal outcome needs to be evaluated.