Low Bioactive Vitamin D Is Associated with Pregnancy-Induced Hypertension in a Cohort of Pregnant HIV-Infected Women Sampled Over a 23-Year Period

Abstract

Objective: To examine the association of vitamin D insufficiency and risk of pregnancy-induced hypertension (PIH) among human immunodeficiency virus (HIV)-infected pregnant women.

Study design: This is a retrospective cohort study evaluating the impact of low maternal vitamin D levels on PIH and perinatal outcomes among HIV-infected pregnant women receiving care at an urban HIV center from 1991 to 2014.

Results: A total of 366 pregnant women were included, of which 11% developed PIH. Lower levels of 25-hydroxyvitamin D (25(OH)D) and bioactive 1,25-dihydroxyvitamin D (1,25(OH)₂D) were associated with increased HIV disease activity. 25(OH)D levels were not significantly associated with the incidence of PIH. Higher 1,25(OH)₂D levels were associated with reduced incidence of PIH in univariate (odds ratio, OR: 0.87 [95% confidence interval, CI: 0.79-0.95], p = 0.004) and multivariate (OR: 0.88 [95% CI: 0.80-0.97], p = 0.010) analyses. No association was found between 25(OH)D levels and other obstetric outcomes. Lower 1,25(OH)₂D levels were associated with group B Streptococcus colonization (OR: 0.92 [95% CI: 0.86-0.99]) and low birth weight (LBW) (OR: 0.90 [95% CI: 0.83-0.98]) on multivariate analysis. Mean 1,25(OH)₂D levels were significantly lower in women with preterm delivery and LBW infants.

Conclusion: Lower bioactive vitamin D levels are related to PIH in HIV-infected women. This association may be related to the coexistence of abnormal placental vitamin D metabolism and abnormal placental implantation.