[Abstract]ObjectiveTo evaluate whether combined supplementation of vitamin C and E in pregnant women can reduce the risk for preeclampsia. MethodsElectronic databases were searched for randomized controlled trials investigating pregnancy outcomes in women following exposure to combined vitamin C and E supplementation since the establishment of the database to Oct. 2010. The end-point of the study was preeclampsia. The relative risk (RR) and confidence interval (CI) for each included studies were pooled and heterogeneity analysis was performed by using RevMan 5.0.25 software. MethodsTotally 10 studies involving 19 656 pregnant women at risk of preeclampsia were included, with 9 823 receiving vitamin C and E and 9 833 receiving placebo. The pooled RR values for preeclampsia in all studies, the studies with high quality, and the studies with low quality were 0.94 (95% CI of 0.80-1.11, P=0.49), 1.02 (95% CI of 0.91-1.14, P=0.79), and 0.40 (95% CI of 0.15-1.10, P=0.08), respectively. MethodsCombined vitamin C and E supplementation has no potential benefit in reducing the risk for preeclampsia.