The association between periconceptional folic acid supplementation and congenital heart defects: A case–control study in China

ObjectiveThis study aims to evaluate the association between folic acid (FA) supplementation and congenital heart defects (CHDs).MethodsThis hospital-based case–control study initiated in 2010 in China analyzed 358 cases and 422 controls. The adjusted odds ratio (AOR) calculated using a logistic model was used to assess the association between FA supplementation and CHDs.ResultsCompared with a mother who reported no FA supplementation, mothers who reported FA supplementation were less likely to have offspring with isolated CHD(s) (AOR = 0.52, 0.34–0.78) and multiple complex conditions (AOR = 0.27, 0.14–0.55). However, mothers who reported FA supplementation for less than 1 month regardless of the start time of supplementation, did not have a significantly lower risk of having an offspring with isolated or multiple complex conditions. Mothers who reported FA supplementation for ≧ 3 months beginning before conception had a significantly lower risk of having children with isolated CHD(s) (AOR = 0.31, 0.18–0.54).ConclusionFA-supplementation is associated with reduced risk of CHDs. The earlier FA supplementation begins before pregnancy and the longer supplementation lasts, the lower the risk of CHDs is.

► Congenital heart defects (CHD) is associated with folic acid (FA) supplement..
► Longer duration of FA supplement has more effective on prevention of CHD.
► The preventive effect of FA and FA-containing multivitamin on CHD is no different.