Combined vitamin C and E supplementation for preeclampsia: No significant effect but significant heterogeneity?

摘要

Dear Editor, We have read with interest the recent meta-analysis by Rahimi et al. The results of this meta-analysis are in accordance with a previous meta-analysis regarding the effects of the combination of vitamin C and E on pre-eclampsia prevention. Nonetheless, despite the uniformity of results between these two meta-analyses, the updated results of the meta-analysis by Rahimi et al. revealed a statistical heterogeneity for the incidence of preeclampsia in the comparison of vitamin combination versus placebo. The authors performed a sensitivity analysis by excluding two of the trials on account of the fact that the supplementation was initiated after 18 weeks of gestation and no statistical heterogeneity was observed for the remaining five studies.