In a historical cohort study, we compared the occurrence
of PE between pregnant women exposed to folic acid
antagonists and nonexposed women (matched by year of
childbirth, type of institute at birth, and mother’s residence
(postal code), using the 1980 to 2000 Canadian province of
Saskatchewan databases. The risks of PE (adjusted OR 1.52,
95% confidence interval (95% CI): 1.39, 1.66) and severe PE
(OR: 1.77, 95% CI: 1.38, 2.28) were increased in mothers withfolic acid antagonist exposure [14]. Supplementary analyses
by tight matching with propensity scores restricting study
participants to first and second trimester exposure and to
specific categories of folic acid antagonists yielded similar
results. Folic acid antagonists include a broad spectrum of
drugs with a common mechanism of depleting maternal
folate. Findings from the effect of maternal exposure to folic
acid antagonists on the increased risk of PE add to the weight
of evidence that folic acid supplementation may decrease the
risk of PE.