Incidence and Clinical Correlates of Vitamin D Deficiency in Hypertensive Pregnant Women

Abstract

Background: Hypertensive disorders of pregnancy (HDP) are major contributors to maternal and neonatal morbidity and mortality. Emerging evidence suggests that vitamin D deficiency may play a role in their pathogenesis through its effects on vascular endothelial function, inflammation, and placental development.

Aim: To determine the incidence and clinical correlates of vitamin D deficiency in hypertensive pregnant women.

Materials and Methods: A cross-sectional observational study was conducted on 99 hypertensive pregnant women admitted to the Department of Obstetrics and Gynaecology at a tertiary care center. Clinical evaluation, obstetric history, and biochemical assessment of serum 25-hydroxyvitamin D [25(OH)D] levels were performed using a quantitative ELISA method. Vitamin D deficiency was defined as serum 25(OH)D <20 ng/mL. Associations between vitamin D levels, HDP subtypes, and maternal-neonatal outcomes were analyzed using chi-square tests, t-tests, and ANOVA, with p < 0.05 considered statistically significant.

Results: Vitamin D deficiency was observed in 76.5% of the participants (95% CI: 68.1-84.9%). The mean serum 25(OH)D concentration was 14.51 ± 7.06 ng/mL. The mean maternal age was 27.31 ± 4.47 years, and the mean birth weight was 2.35 ± 0.72 kg. The prevalence of deficiency was highest among women with superimposed preeclampsia (90.9%) and non-superimposed preeclampsia (89.5%) compared to gestational hypertension (67.4%). ANOVA revealed a significant difference in mean vitamin D levels across HDP types (F(3,95)=5.34, p=0.002). However, no significant association was found between vitamin D deficiency and mode of delivery (p=0.636) or NICU admission (p=0.213).

Conclusion: Vitamin D deficiency is highly prevalent among hypertensive pregnant women, with lower serum levels observed in more severe hypertensive subtypes. These findings suggest a potential association between vitamin D status and HDP severity, emphasizing the need for routine screening and preventive supplementation strategies in antenatal care.