Folate intake and the primary prevention of non-neural birth defects.

OBJECTIVES: To investigate whether maternal periconceptional folate intake is associated with a reduction in selected non-neural birth defects in Western Australia (WA).

METHODS: Case-control study of folate intake in women whose infants had orofacial clefts (62); congenital heart defects (151); urinary tract defects (117); limb reduction defects (26); or other major birth defects (119); and 578 control women.

RESULTS: Neither folic acid supplements nor dietary folate intake in women not using supplements was significantly associated with a reduction in risk in any of the case groups. In contrast to neural tube defects, WA population data for orofacial clefts, heart defects, limb reduction defects and urinary tract defects showed no fall in prevalence since the introduction of folate promotion and voluntary food fortification.

CONCLUSIONS: This study provides no evidence of folate being an important factor in the prevention of birth defects other than neural tube defects.