Maternal Vitamin D receptor gene variant genotype and its influence on preterm birth, low birth weight, and fetal death. A case-control study from Northeast India

With the background of association and importance of the Vitamin D receptor (VDR) pathway in pregnancy, we aimed to evaluate the significance of maternal VDR gene polymorphism in the pathophysiology of preterm pregnancy and associated complications. A total of 120 Preterm delivery (PTD) cases and 111 healthy term delivery(TD) cases were evaluated using PCR-RFLP based approach. The distribution of variant genotype for Apa I (AA + aA) and FokI (FF + fF) was significantly higher in TD cases (p < 0.001 and p = 0.003) compared to PTD cases whereas the genotype for TaqI (TT + tT) was comparable between TD and PTD cases (p = 0.368). The variant genotype ApaI (AA + aA) and TaqI (Tt + TT) was found to decreased the risk of PTD. No association with low birth weight (LBW) and fetal death for different haplotypes was observed. However, the individual homozygous genotype AA for ApaI was associated with the LBW (p = 0.001), and the TT genotype for TaqI was found to be associated with the increased risk of preterm birth (OR = 7.5, p = 0.004) as well as negative pregnancy outcome (p = 0.005). The study provides crucial information regarding the association of a particular VDR genotype with preterm birth and associated complications and it might hold a prognostic significance in the future.