A study of relationship between maternal serum vitamin D levels during pregnancy and risk of preterm births

Abstract

Background: Preterm birth is the leading cause of death among neonates and children under 5 years of age with long-term adverse sequelae in the survivors. Vitamin D is being increasingly researched for its protective effect against the risk for preterm births due to its role in immunomodulatory and anti-inflammatory processes. An observational study was undertaken to study the relationship between maternal serum Vitamin D levels during peripartum period and the risk for preterm birth. Materials and Methods: This study employed a cross sectional design in a tertiary care center on 569 patients to study the relationship between maternal serum Vitamin D levels and risk of preterm births. Results: A total of 569 samples of maternal and neonatal serum were analyzed for serum 25-hydroxyvitamin D (25[OH]D) levels. Four hundred and sixty-four (81.54%) mothers had Vitamin D sufficient (VDS) levels ≥30 ng/ml and 105 (18.45%) had Vitamin D deficient (VDD) levels <30 ng/ml. Out of the total 569 deliveries, 501 (88.04%) occurred at term (≥37 weeks' period of gestation) and 68 (11.95%) were preterm (<37 weeks' period of gestation). The incidence of preterm births was 10.77% in the VDS group as compared to 17.14% in the VDD group (P = 0.038). The mean cord blood 25(OH) D level of preterm neonates was 12.68 ng/ml (standard deviation [SD] 3.85, range 7.9–22) and term neonates was 13.63 ng/ml (SD 3.76, range 8.2–27) (P = 0.035). Conclusion: The rate of preterm delivery was 1.59 times higher in mothers with Vitamin D deficiency. Furthermore, the mean cord blood Vitamin D levels were higher in term newborns.