RISKS OF OROFACIAL CLEFTS IN CHILDREN BORN TO WOMEN USING MULTIVITAMINS CONTAINING FOLIC-ACID PERICONCEPTIONALLY

Women are advised to take folic acid before they conceive as a precaut ion against neural-tube defects. However, the use of folic acid in pre venting orofacial clefts is unknown. We investigated whether a woman's periconceptional use of multivitamins containing folic acid was assoc iated with a reduced risk of orofacial clefts. We derived data from a population-based case-control study of fetuses and liveborn infants wi th orofacial anomalies among a 1987-89 cohort of births in California. We interviewed 731 (84.7%) of eligible mothers with orofacial cleft c ase infants and 734 (78.2%) mothers with non-malformed control infants . We found a reduced risk of orofacial clefts if the mother had used m ultivitamins containing folic acid during the period from one month be fore through two months after conception. The odds ratios ranged from 0.50-0.73 depending on cleft phenotype. Controlling for the potential influence of other variables did not substantially alter the results. Maternal daily consumption of cereal containing folic acid was also as sociated with a reduced risk of orofacial clefts. Women who used multi vitamins containing folic acid periconceptionally had a 25-50% reducti on in risk for offspring with orofacial clefts compared to women who d id not use such vitamins. However, this association may not be attribu table to folic acid specifically, but may be a consequence of other mu ltivitamin supplement components, or behaviours, that are highly corre lated with the use of multivitamins containing folic acid.