Effect of high dose folic acid supplementation in pregnancy on pre-eclampsia (FACT): double blind, phase III, randomised controlled, international, multicentre trial

Study answer

What this study found

High-dose folic acid did not prevent pre-eclampsia or improve maternal or neonatal outcomes in this high-risk pregnancy population. Pre-eclampsia occurred in 169/1144 (14.8%) in the folic acid group versus 156/1157 (13.5%) in the placebo group (relative risk 1.10, 95% CI 0.90 to 1.34; P=0.37). Other key outcomes were also not improved, including severe pre-eclampsia (2.10% vs 1.4%; RR 1.52, 0.81 to 2.84), perinatal mortality (1.7% vs 2.7%; RR 0.63, 0.37 to 1.05), and NICU admission (22% vs 20%; RR 1.08, 0.91 to 1.28). The authors concluded that 4.0 mg daily folic acid from early second…

Study & population

Double-blind, phase III, randomized controlled international multicentre trial in pregnant women at high risk for pre-eclampsia, including those with pre-existing hypertension, prepregnancy diabetes, twin pregnancy, prior pre-eclampsia, or BMI ≥35 kg/m2.

Intervention

Pregnant women at high risk for pre-eclampsia were assigned to oral folic acid 4.0 mg daily, given as four 1.0 mg tablets, from 8 to 16 completed weeks of gestation until delivery.

Key limitation

The trial allowed background prenatal vitamins or low-dose folic acid, and more than 80% of participants reported prior folic acid or folic acid-containing vitamin use, which may have reduced contrast between groups.

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Original abstract