Supplementation with vitamins C and E during pregnancy for the prevention of preeclampsia and other adverse maternal and perinatal outcomes: a systematic review and metaanalysis

OBJECTIVE: To determine whether supplementation with vitamins C and E during pregnancy reduces the risk of preeclampsia and other adverse maternal and perinatal outcomes. STUDY DESIGN: Systematic review and metaanalysis of randomized controlled trials. RESULTS: Nine trials involving a total of 19,810 women were included. Overall, there were no significant differences between the vitamin and placebo groups in the risk of preeclampsia (9.6% vs 9.6%; relative risk, 1.00, 95% confidence interval, 0.92-1.09). Similar results were obtained when subgroup analyses were restricted to women at high risk or low/moderate risk for preeclampsia. Women supplemented with vitamins C and E were at increased risk of developing gestational hypertension and premature rupture of membranes, and decreased risk of abruptio placentae. There were no significant differences between the vitamin and placebo groups in the risk of other adverse maternal or fetal/perinatal outcomes. CONCLUSION: Supplementation with vitamins C and E during pregnancy does not prevent preeclampsia.