Effect of folic acid supplementation during pregnancy on gestational hypertension/preeclampsia: A systematic review and meta-analysis.

Xiaolin Hua, Jiewen Zhang, Yanfang Guo, Minxue Shen, Laura Gaudet, Ghayath Janoudi, Mark Walker, Shi Wu Wen

Journal: Hypertension in pregnancy 2018;35(4):447-460

PMID: 27315401

Abstract

OBJECTIVE

To evaluate the effect of folic acid supplementation during pregnancy on the risk of gestational hypertension/preeclampsia.

METHODS

A systematic review and meta-analysis were conducted. Medline, Embase, Scopus, and the Web of Science were searched from inception to December 2014.

RESULTS

Out of 1224 potentially relevant studies, 13 studies met our inclusion criteria (2 randomized controlled trials (RCTs), 10 cohort studies, and 1 case-control study). The pooled relative risk (RR) and 95% confidence interval (CI) of the two RCTs were 0.62 (0.45-0.87) in the trial arm as compared with the placebo arm. The pooled RR was 0.92 (95% CI: 0.79-1.08) for nine cohort studies with available data on folic acid supplementation in pregnancy and gestational hypertension/preeclampsia. Pooled RR was 0.88 (95% CI: 0.76-1.02) for eight cohort studies with available data on folic acid supplementation and preeclampsia.

CONCLUSION

Whether folic acid supplementation in pregnancy can prevent the occurrence of gestational hypertension/preeclampsia remains uncertain.

Address: a Department of Obstetrics , Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai , China.; b Department of Obstetrics and Gynecology, Faculty of Medicine , OMNI Research Group, University of Ottawa , Ottawa , Ontario , Canada.; c Clinical Epidemiology Program , Ottawa Hospital Research Institute , Ottawa , Ontario , Canada.; d Department of Obstetrics and Gynecology , Beijing Friendship Hospital, Capital Medical University , Beijing , China.; e School of Public Health , Central South University , Changsha , China.; f Canadian Agency for Drugs and Technologies in Health , Ottawa , Ontario , Canada.; g School of Epidemiology, Public Health, and Preventive Medicine , University of Ottawa Faculty of Medicine , Ottawa , Ontario , Canada.

DOI: 10.1080/10641955.2016.1183673