Research paper
Folic Acid Supplementation During Early Pregnancy and the Risk of Gestational Hypertension and Preeclampsia
Study answer
What this study found
Among 193,554 participants, folic acid use did not reduce the risk of gestational hypertension or preeclampsia. Incidence: gestational hypertension 9.7% with use vs 9.4% without; preeclampsia 2.5% with use vs 2.4% without. Adjusted risk ratios were 1.08 (95% CI 1.04–1.11) for gestational hypertension and 1.11 (95% CI 1.04–1.18) for preeclampsia, indicating no protective effect and a potential small increase in risk that may reflect confounding. Daily intake of 400 μg folic acid alone during early pregnancy cannot prevent gestational hypertension or preeclampsia in this population; folic acid…
- Study & population
- Population-based cohort study of pregnant women registered in the pregnancy monitoring system in two southern Chinese provinces (Jiangsu and Zhejiang) from 1993 to 1996; included women without chronic hypertension or diabetes before 20 weeks; total N=193,554 (92,731 used folic acid; 100,823 did not); mean age ~24–25 years; predominantly Han ethnicity;…
- Intervention
- 400 μg folic acid daily, started at registration with the pregnancy monitoring system and continued until completion of the first trimester; taken alone (not with multivitamins).
- Key limitation
- Observational, nonrandomized design with potential residual confounding; limited to two southern provinces with predominantly Han population, limiting generalizability; possible misclassification or incomplete assessment of folic acid adherence; unmeasured factors (eg, smoking) not fully accounted for; dietary folate…
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Open PDFOriginal abstract
Emerging evidence has suggested that folic acid–containing multivitamins may markedly reduce the risk of gestational hypertension or preeclampsia. We examined whether maternal supplementation with folic acid alone during early pregnancy can prevent t…