Impact of Maternal Factors Before and During Pregnancy on Newborn Cord Blood Vitamin D Concentrations: A Multicenter Prospective Cohort Study.

Abstract

To examine the association between maternal prepregnancy body weight status and newborn cord blood vitamin D concentrations and to explore the potential mechanism of maternal prenatal dietary factors and vitamin D concentrations in this association. Pregnant women were recruited from antenatal clinics in Hong Kong to assess risk factors on maternal prenatal and newborn cord blood vitamin D concentrations. Regression and path analyses were performed to explore the contribution of maternal factors before and during pregnancy to vitamin D concentrations in maternal prenatal blood and in newborn cord blood. Among 2726 mother-child dyads recruited, 9.94% of pregnant women and 82.91% of neonates were vitamin D insufficient. Insufficient total vitamin D intake and being overweight before pregnancy were risk factors for both maternal prenatal and newborn cord blood vitamin D insufficiency (aOR, 1.39-4.37; all P < .05). Path analyses showed that newborn cord blood vitamin D concentration was associated directly with maternal total vitamin D intake and indirectly with maternal prepregnancy body weight status via maternal prenatal vitamin D concentrations. Low vitamin D intake from diet and supplements was identified as a risk factor for vitamin D insufficiency in both pregnant women and their newborns. High prevalence of vitamin D insufficiency in neonates indicates the necessity of establishing clear guidelines to help pregnant women achieve their recommended daily vitamin D intake.