Low maternal alcohol consumption during pregnancy and oral clefts in offspring: the Slone Birth Defects Study

The association between maternal alcohol consumption during pregnancy and oral clefts in offspring remains unclear. We studied this relation in a case-control surveillance study of birth defects.

From 1983 to 1997, we recruited 5956 study subjects from greater Boston, Philadelphia, Toronto, and parts of Iowa. The cases were liveborn infants with cleft palate alone (CP; n = 205), cleft lip and palate (CLP; n = 383), cleft lip alone (CL; n = 259), or Pierre-Robin sequence (n = 65). The controls (n = 4272) were infants who had no oral clefts but had one or more of the following defects: malformations of the digestive tract, reproductive organs, abdominal wall, and respiratory tract; chromosomal anomalies; inguinal hernia; tumors; and Mendelian inherited disorders. Based on maternal reports of alcohol consumption during the first 4 months of pregnancy, we derived average weekly consumption, average number of drinks per drinking day, and the maximum number of drinks consumed in a given day. The mothers also provided data on potential confounding or modifying variables, such as vitamin supplement use.

There was no relation between maternal alcohol consumption during pregnancy and CL or CP. The odds ratios (ORs) for cleft lip with or without palate (CL/P) were 1.0, 1.1, and 0.9 in women who consumed <1.0, 1.0-2.9, and 3.0 + drinks per week, respectively. These findings did not change when we considered possible modifying effects of vitamin supplement use.

Our findings do not support an association between oral clefts and a low level of alcohol consumption.