Alcohol consumption during pregnancy and the risk of early stillbirth among singletons.

The purpose of this study is to investigate the association between maternal alcohol intake in pregnancy and the occurrence of early stillbirth using a retrospective cohort analysis of singleton births in Missouri that occurred in the period 1989 through 1997 (N=655,979). We used Cox proportional hazards regression to generate adjusted risk estimates for total, early, and late stillbirth associated with maternal alcohol intake and used the Robust Sandwich Estimator to adjust for intracluster correlations among sibships. Overall, a total of 3,508 counts of stillbirth were identified, yielding a stillbirth rate of 5.3 per 1,000. Among mothers who consumed alcohol during pregnancy, the stillbirth rate was 8.3 per 1,000. Mothers who consumed alcohol while pregnant were 40% more likely to experience stillbirth as compared with nondrinking mothers (adjusted hazards ratio=1.4, 95% confidence interval: 1.2-1.7). A dose-response relationship was evident; mothers who consumed five or more drinks per week during pregnancy experienced a 70% elevated risk of stillbirth compared with nondrinking mothers (adjusted hazards ratio=1.7; 95% confidence interval: 1.0-3.0). The risk of early stillbirth was 80% higher among drinking mothers compared with abstainers (adjusted hazards ratio=1.8; 95% confidence interval: 1.3-2.3). The elevated risks for both early and late stillbirth did not reach statistical significance when broken down by level of alcohol intake. In conclusion, maternal drinking during pregnancy is associated with an increased risk of early stillbirth. These findings underscore the need to reinforce current counseling strategies toward pregnant women and women who intend to conceive on the detrimental effects of alcohol use in pregnancy.