Maternal vitamin D deficiency during pregnancy elevates the risks of small for gestational age and low birth weight infants in Chinese population.

Abstract

Vitamin D deficiency is common in pregnant women. Nevertheless, the association between maternal vitamin D status during pregnancy and the risk of having small for gestational age (SGA) and low birth weight (LBW) infants is uncertain. The objective of this study was to investigate whether there is a correlation between maternal vitamin D deficiency during pregnancy and the risk of having SGA and LBW infants in a Chinese population. This was a population-based birth cohort study that recruited 3658 eligible mother-and-singleton-offspring pairs. Serum 25-hydroxyvitamin D was measured by RIA. The rate and relative risk (RR) for SGA and LBW infants were calculated among subjects with vitamin D deficiency and insufficiency during pregnancy. There was a positive correlation between maternal serum 25-hydroxyvitamin D level and offspring birth weight (r = 0.477; P < .001). Further analysis showed that 4.98% of neonates were LBW infants among the subjects with vitamin D deficiency (RR, 12.00; 95% confidence interval [CI], 4.37, 33.00) and 1.32% among the subjects with vitamin D insufficiency (RR, 3.18; 95% CI, 1.07, 9.48). After adjustment for confounders, the RR for LBW infants was 12.31 (95% CI, 4.47, 33.89) among subjects with vitamin D deficiency and 3.15 (95% CI, 1.06, 9.39) among subjects with vitamin D insufficiency. Moreover, 16.01% of neonates were SGA infants among subjects with vitamin D deficiency (RR, 5.72; 95% CI, 3.80, 8.59) and 5.59% among subjects with vitamin D insufficiency (RR, 1.99; 95% CI, 1.27, 3.13). After adjustment for confounders, the RR for SGA infants was 6.47 (95% CI, 4.30, 9.75) among subjects with vitamin D deficiency and 2.01 (95% CI, 1.28, 3.16) among subjects with vitamin D insufficiency. Maternal vitamin D deficiency during pregnancy elevates the risk of SGA and LBW infants in a Chinese population.