Hypertension during pregnancy increases fetal growth retardation, preterm deliveries, and perinatal deaths, and yet its causes remain unclear. In HIV-infected women, preterm birth additionally increases the risk of HIV transmission to the infant, Oxidative stress and endothelial cell dysfunction of the placenta have been implicated in the development of hypertension during pregnancy. Vitamin intake can reduce oxidative stress and improve endothelial function. We therefore evaluated the effect of multivitamin (20 mg thiamine, 20 mg riboflavin, 25 mg B-6, 50 ?g B-12, 500 mg C, 30 mg E, and 0.8 mg folic acid) and vitamin A supplements (30 mg β-carotene plus 5000 IU preformed vitamin A) in relation to hypertension during pregnancy (systolic blood pressure > 140 mm Hg or diastolic blood pressure a 90 mm Hg at any time during pregnancy). In a double-blind, placebo-controlled, randomized, clinical trial, conducted among 1078 HIV-positive pregnant Tanzanian women, those who received multivitamins were 38% less likely to develop hypertension during pregnancy than those who did not [relative risk (RR) = 0.62, 95% CI 0.40-0.94, P = 0.03]. There was no overall effect of vitamin A on hypertension during pregnancy (RR = 1.00, 95% CI 0.66-1.51, P = 0.98). Hypertension during pregnancy was more likely in women with high baseline systolic blood pressure (>120 vs. ≤120 mm Hg) (RR = 6.02, 95%CI 2.59-13.97, P < 0.001), and those with higher mid-upper arm circumference (RR = 1.12, 95% CI 1.04-1.19, P = 0.002). Taking multivitamins containing vitamins B, C, and E during pregnancy may be an inexpensive and effective strategy to improve the health of the mother and baby. © 2005 American Society for Nutritional Sciences.
