Maternal periconceptional alcohol consumption and risk for orofacial clefts

Objective: To investigate whether periconceptional maternal alcohol consumption increased the risk of delivering infants with orofacial cleft phenotypes. Design: Data were derived from a large population-based case control study of fetuses and infants among a cohort of California births from 1987 to 1989 (n = 548,844). Information concerning alcohol consumption was obtained by telephone interviews with mothers of 731 infants (84.7% of eligible) with orofacial clefts and of 734 (78.2%) infants in a nonmalformed control group. Results: Thirty-nine percent of mothers in the case group and 42% of mothers in the control group reported that they consumed alcohol during the period 1 month before through 3 months after conception. Relative to nonconsumers, women who reported alcohol consumption (<weekly, weekly, or daily) were not at substantially increased risk of delivering infants with any cleft phenotype. However, for women who reported weekly or more frequent episodes of consuming 25 drinks per drinking occasion compared with those who did not, we observed increased risks for isolated (no other major congenital anomaly) cleft lip with or without cleft palate, odds ratio = 3.4 (95% confidence interval, 1.1 to 9.7); multiple cleft lip with or without cleft palate, odds ratio = 4.6 (1.2 to 18.8); and "known syndrome" clefts, odds ratio = 6.9 (1.9 to 28.6). Adjustment for maternal cigarette smoking, race, education, or vitamin use did not substantially change observed risks. Conclusion: We observed a lack of increased risks of clefts for relatively low quantities of maternal alcohol consumption and increased risks of clefts for higher quantities of maternal alcohol consumption.