The association between maternal alcohol use and smoking in early pregnancy and congenital cardiac defects

Alcohol use is an extremely prevalent but preventable risk factor among women seeking to become pregnant. Many women continue to use alcohol in the early stages of pregnancy before they are aware they are pregnant. Research is unclear about the role of maternal alcohol use during pregnancy and congenital cardiac defects, one of the leading types of birth defects in the United States.

Data from the Pregnancy Risk Assessment Monitoring Survey (PRAMS) were used to examine maternal alcohol use and its association with congenital cardiac defects. Various measures of alcohol use in the 3 months prior to pregnancy, as well as smoking and other risk factors for congenital cardiac defects, were linked to birth certificate data for nine states over a 10-year period (1996-2005). In this case-control study, cases included infants with a congenital cardiac defect indicated on the birth certificate, and the control group consisted of healthy, normal weight infants with no indication of a congenital abnormality on their birth certificate. Complex samples logistic regression models were used to study the relationships between several measures of alcohol use, including binge drinking and binge drinking on more than once occasion, and the interaction between alcohol use and smoking with the odds of congenital cardiac defects.

A significant increase in congenital cardiac defects was found among mothers who reported binge drinking more than once in the 3 months prior to pregnancy compared to mothers who did not report binge drinking (adjusted odds ratio [aOR] 2.99, 95% confidence interval [CI] 1.19-7.51). There was a significant interaction between any binge drinking or binge drinking more than once and cigarette use, which corresponded to a substancial increase in congenital cardiac defects (aOR 12.65, 95% CI 3.54-45.25 and aOR 9.45, 95% CI 2.53-35.31, respectively).

Multiple episodes of maternal binge drinking in early pregnancy may increase the odds of congenital cardiac defects, and we found this relationship was more dramatic when combined with maternal smoking.