[Periconceptional folates and the prevention of orofacial clefts: role of dietary intakes in France]. / Folates en période péri-conceptionnelle et prévention du risque de fente orofaciale: rôle des apports alimentaires en France.

BACKGROUND: Orofacial clefts are among the most frequent congenital malformations at birth with a prevalence of 1 in 700 births in Europe. The implication of environmental factors in their etiology has been demonstrated. The role of folic acid, or folates, in the prevention of orofacial clefts is still debated although its efficacy has been demonstrated for the prevention of neural tube defects. METHODS: A case-control study was conducted in 7 hospitals in 4 centers in France. Cases (N=240) were children with non-syndromic orofacial cleft referred to one of the study hospitals for initial surgical repair in 1998 and 1999. Controls (N=236) matched for gender, geographic origin, and age were chosen in paediatric departments of the same hospitals. Usual dietary intake of folates was estimated using a food frequency questionnaire submitted to the mother at hospital. During the same interview, data on sociodemographic characteristics, medical and obstetrical history, tobacco and alcohol consumption, and vitamin supplements, were obtained. Odds ratios associated with quintiles of dietary intake of folates were estimated using logistic regression adjusting for known confounders. RESULTS: A significant dose-response relationship between the risk of orofacial clefts and a decrease in the intake of folates from diet was found, stronger for cleft palate without cleft lip. Only few women (<1%) declared having taken vitamin supplements containing folic acid when planning their pregnancy. CONCLUSION: Our study further suggests that folates are useful for the prevention of orofacial clefts during the periconceptual period. In our study, the estimated average daily intake of folates (270 microg/day) was below French national recommendations for the prevention of neural tube defects (400 microg/day). Since those insufficient folate intakes during the periconceptual period are not presently met by vitamin supplementation, the solution may come from the food fortification program proposed and implemented by the National Agency for Food Safety (AFSSA).