Effects of Maternal Vitamin D Deficiency on the Newborn: A Cohort Study

Abstract

Introduction: Vitamin D deficiency occurs during pregnancy all over the world because of lifestyle modifications, less sun exposure, sunscreen application and reduced amount of vitamin D in diet. At present, there are very limited number of studies regarding the prevalence of vitamin D deficiency during pregnancy and its effects in the newborns in the North Eastern region of India. Aim: To estimate serum vitamin D levels in pregnant women and newborn and correlation between maternal and newborn hypovitaminosis D. The study also assess the association of maternal vitamin D levels with the outcomes of early neonatal period. Materials and Methods: A prospective cohort study was conducted in Assam Medical College and Hospital (AMCH), Dibrugarh, Assam, India, in the Obstetrics and Gynaecology Department over a period of one year (1st July 2019 to 30th June 2020). Seventy pregnant women attending antenatal ward, labour room of AMCH were recruited. The 25-hydroxy vitamin D level was assessed in the maternal and cord blood. Delivery details and foetal parameters were recorded. Primary outcome was to assess the correlation between maternal and cord blood vitamin D level and secondary outcome was to assess the association of maternal vitamin D level with demographic characteristics, economic and obstetrical characteristics, newborn characteristics and perinatal outcome. Analysis of Variance (ANOVA), chi-square test and Fischer’s- exact test, Pearson’s correlation coefficient (r) were used for statistical analysis. Results: Out of 70 participants, majority of the pregnant women (61.43%) were vitamin D deficient, 22.86% were vitamin D insufficient and 15.71% had sufficient vitamin D levels. Maternal vitamin D level was significantly associated with maternal age (p=0.0043) and socio-economic status (p=0.0417). There was a significant positive association between the vitamin D level of the mother with the birth weight (p<0.001), birth length (p=0.0001), head circumference (p=0.0003) and chest circumference (p=0.001) of the newborns and also a positive correlation was found between the vitamin D level of the mother and the cord blood (r=0.984). There was a significant association between the vitamin D level of the mother and perinatal outcomes such as Neonatal Intensive Care Unit (NICU) admission (p=0.0169) and Respiratory Distress Syndrome (RDS) (p=0.0029). Conclusion: The study shows that there is a high prevalence of vitamin D deficiency during pregnancy in North Eastern part of India and it has a significant role in foetal development and perinatal outcomes.