Supplementation of folic acid in pregnancy and the risk of preeclampsia and gestational hypertension: a meta-analysis

Cheng Liu,Zhenyu Zhang,Chongdong Liu,Qiushi Wang

doi:10.1007/s00404-018-4823-4

Abstract

ObjectivesWe aimed to systematically assess the relationship between folic acid supplementation in pregnancy and risk of preeclampsia and gestational hypertension.MethodsThe relevant studies were included by retrieving the Embase, PubMed and Cochrane library databases. Data extraction was conducted by two investigators independently. The risk ratio (RR) and 95% confidence interval (CI) were used as effect indexes to evaluate the relationship between folic acid supplementation and risk of gestational hypertension or preeclampsia. A subgroup analysis was performed according to the supplementation patterns of folic acid. The homogeneity of the effect size was tested across the studies, and publication biases were examined.ResultsIn total, 13 cohort studies and 1 randomized controlled trial study was included, containing 160,562 and 149,320 women with and without folic acid supplementation during pregnancy. Pooled results showed that risk of gestational hypertension was not associated with the supplementation of folic acid. However, folic acid supplementation during pregnancy could significantly reduce the risk of preeclampsia. Moreover, the results of subgroup analysis showed that the decreased preeclampsia risk was associated with supplementation of multivitamins containing folic acid rather than folic acid alone.ConclusionsOur findings indicate that the supplementation of multivitamins containing folic acid during pregnancy could significantly lower preeclampsia risk.

Highlights

Gestational hypertension and preeclampsia are common hypertensive disorders during pregnancy [1, 2]
The results showed that the supplementation of multivitamins containing folic acid significantly decreased the risk of preeclampsia (RR = 0.70, 95% confidence interval (CI) 0.53–0.93, P = 0.01), while the supplementation of folic acid alone had no significant effects on preeclampsia risk (RR = 0.97, 95% CI 0.80–1.17, P = 0.73) (Fig. 4)
A sensitivity analysis was performed by eliminating the included studies one by one, and eventually, the pooled results were not significantly changed (Fig. 5). In this meta-analysis, 14 studies were included and pooled results showed that the supplementation of folic acid during pregnancy significantly reduced preeclampsia risk, but had no effects on gestational hypertension risk

Summary

Introduction

Gestational hypertension and preeclampsia are common hypertensive disorders during pregnancy [1, 2]. Preeclampsia is a devastating complication of pregnancy responsible for maternal mortality and morbidity [3, 4]. Mothers with preeclampsia during pregnancy may result in neurocognitive dysregulation and suboptimal infant development in offspring [5]. Hypertension is a risk factor for diabetes and cardiovascular disease in later life [6, 7]. Preeclampsia is always caused by impaired placental perfusion, but other risk factors for preeclampsia remain unclear [8]

Objectives

Methods

Results

Conclusion