The prevention of congenital anomalies with periconceptional folic acid supplementation.

Large randomized trials have demonstrated the critical role of folic acid supplementation in the prevention of neural tube defects. Since 1992, a number of national and international professional societies have released guidelines recommending folic acid supplementation of at least 0.4 mg/day for all women of childbearing age or women planning pregnancies, and 4 mg/day for women with a previous infant with a neural tube defect. Furthermore, a reduction in the incidence of congenital cardiac and urologic anomalies has been demonstrated in some studies following periconceptional folic acid supplementation. There is growing evidence of a possible role of folic acid supplementation in the prevention of other congenital anomalies, including cardiac defects. Since 1998, mandatory fortification of certain foods with folate has been associated with at least a 54% reduction in the incidence of open neural tube defects, yet rates of periconceptional folic acid use remain suboptimal, especially in minority women. Innovative strategies in educating women, health-care providers, and pharmacists on the benefits of folic acid supplementation need to be explored. Mandatory folate fortification of foods needs to be defined and monitored.