Folic Acid Supplementation in Early Second Trimester and the Risk of Preeclampsia

Objective The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia. Study Design We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks’ gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis. Results A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 μmol/L), decreased plasma homocysteine (on average 0.39 μmol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75). Conclusion Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.