Association of Maternal Vitamin D Deficiency with Severity of Hypertensive Disorders of Pregnancy

Abstract

Background: Vitamin D deficiency has been implicated in the pathogenesis of hypertensive disorders of pregnancy (HDP) through its effects on placental function, vascular health, and immune modulation. However, its relationship with disease severity remains inadequately characterized in Indian populations.

Aim: To assess the association of maternal vitamin D deficiency with the severity of hypertensive disorders of pregnancy.

Materials and Methods: This cross-sectional analytical study included 99 pregnant women diagnosed with HDP at a tertiary care hospital. Participants were categorized into gestational hypertension (GHTN), non-superimposed preeclampsia (NSPE), superimposed preeclampsia (SPE), and impending eclampsia (IE). Serum 25-hydroxyvitamin D levels were measured using chemiluminescent immunoassay (CLIA). Vitamin D deficiency was defined as <20 ng/mL. Maternal and fetal outcomes, including mode of delivery, NICU admission, and birth weight, were recorded. Data were analyzed using chi-square, ANOVA, and t-tests with significance set at p < 0.05.

Results: The overall prevalence of vitamin D deficiency was 76.5% (95% CI 67.2-83.8), with mean serum 25(OH)D = 14.51 ± 7.06 ng/mL. Deficiency was most frequent in SPE (90.9%) and NSPE (89.5%) compared to GHTN (67.4%). One-way ANOVA revealed a significant difference in vitamin D levels across HDP categories (F = 5.34, p = 0.002), with the lowest levels observed in severe preeclampsia. Maternal and neonatal outcomes showed no statistically significant correlation with vitamin D status (p > 0.05), although lower vitamin D tended to associate with preterm birth and NICU admission.

Conclusion: Vitamin D deficiency is highly prevalent among women with hypertensive disorders of pregnancy and is significantly associated with disease severity, particularly in preeclampsia. Screening and correction of vitamin D deficiency during antenatal care may serve as a cost-effective adjunct in reducing HDP-related morbidity.