BACKGROUND AND PURPOSE:

• Previous studies have suggested that high dose folic acid may prevent preeclampsia in women at higher risk
• Wen et al. (BMJ, 2018) assessed the efficacy of high dose folic acid supplementation for prevention of preeclampsia in women with at least one risk factor

METHODS:

• Randomized, phase III, double blinded international, multicenter clinical trial (RCT)
• Participants: At least one of the following risk factors
  • Pre-existing hypertension
  • Prepregnancy diabetes (type 1 or 2)
  • Twin pregnancy
  • Pre-eclampsia in previous pregnancy
  • Body mass index ≥35
• Women received either
  • Daily high dose 4 mg folic acid (four 1.0 mg oral tablets) starting between 8 and 16 weeks of gestation and ending at delivery
  • Matched placebo
• Primary outcome
  • Preeclampsia, defined as hypertension presenting after 20 weeks’ gestation with major proteinuria or HELLP syndrome
• Secondary outcomes
  • Additional obstetrical outcomes, including severe preeclampsia and neonatal outcomes
• Clinical significance was defined as a 30% reduction in preeclampsia when taking folic acid
• 80% power, two sided type 1 error 0.05

RESULTS:

• 1,144 folic acid group | 1,157 placebo group
  • 2,301 were included in the intention to treat analyses
• Preeclampsia occurred in
  • Folic acid group: 14.8% women
  • Placebo group: 13.5%
  • Relative risk (RR) 1.10; 95% CI, 0.90-1.34 (P=0.37)
• There was no evidence of differences between the groups for any other adverse maternal or neonatal outcomes

CONCLUSION:

• Folic acid supplementation with 4.0 mg/day beyond the first trimester does not prevent preeclampsia in women at high risk for this condition
• The researchers have received additional funding to follow up participants in this study and determine long term effects of folic acid on maternal and child health

Learn More – Primary Sources:

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

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NTDs and Pregnancy – Folic Acid Recommendations

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