Background. Alcohol-use is an identifiable and preventable risk factor among women seeking to become pregnant. Maternal alcohol-use during pregnancy may be related to congenital cardiac defects, one of the leading types of birth defects.

Methods. This study used data from the Pregnancy Risk Assessment Monitoring Surveillance (PRAMS), an ongoing national study administered in selected participating states. Alcohol use and other risk factors were obtained from the PRAMS survey linked to birth defects data from birth certificates in 9 participating states over a ten year period (1996-2005). In this study cases included infants born with a congenital cardiac defect as indicated on the birth certificate. Cases were compared to two control groups. One control group consisted of infants with no indication of a congenital abnormality on their birth certificate. A second control group consisted of infants born with Down's syndrome indicated on their birth certificate. Odds ratios for congenital cardiac defects were computed for maternal alcohol use, frequent drinking, binge drinking and continued drinking through logistic regression.

Results. Differences were found in the odds of congenital cardiac defects among mothers who reported binge drinking on more than once occasion in the 3 months prior to pregnancy. Maternal binge drinking on multiple occasions was found to be a risk factor for congenital cardiac defects (OR 2.99; CI 1.19-7.51) when nonaffected controls were used as a reference group. Significant interaction between binge drinking and smoking in the 3 months prior to pregnancy was noted with both control groups.

Conclusion. Binge drinking in early pregnancy may be a risk factor for congenital cardiac defects, particularly when combined with smoking.