A Meta-Analysis on the Efficacy and Safety of Combined Vitamin C and E Supplementation in Preeclamptic Women

Objective: To evaluate whether vitamin C and E co-supplementation of women at risk of preeclampsia can reduce maternal and neonatal disorders. Method: Electronic databases were searched up to May 2008 to find studies investigating pregnancy outcomes in women at risk of preeclampsia following exposure to combined vitamin C and E supplementation. The outcomes of interest were gestational hypertension, preeclampsia, preterm delivery, small for gestational age, and low birth weight. The relative risk (RR) and confidence interval (CI) for the individual studies were pooled and heterogeneity analysis was performed. Results: Seven studies involving 5969 pregnant women at risk of preeclampsia were included: 2982 received vitamin C and E and 2987 received placebo. The RRs are 1.3 (95% CI of 1.08-1.57, p = 0.0066) for gestational hypertension, 0.7 (95% CI of 0.58-1.08, P = 0.1653) for preeclampsia, 1.12 (95% CI of 0.96-1.32, p = 0.141) for preterm delivery, 1.04 (95% CI of 0.94-1.15, p = 0.4789) for small for gestational age, and 1.13 (95% CI of 1.004-1.27, p = 0.0429) for low birth weight. Conclusion. Combined vitamin C and E supplementation not only have no potential benefit in improvement of maternal and neonatal outcome but increase the risk of gestational hypertension in women at risk of preeclampsia and low birth weight in neonates.