Alcohol consumption during pregnancy and the risk of preterm delivery.

The authors evaluated the association between amount and type of alcohol consumed during pregnancy and the risk of preterm delivery and whether the relation differs among very (<32 completed weeks) and moderate (from 32 to <37 completed weeks) preterm delivery. The study is based on data of 40,892 pregnant women included in the first part of the Danish National Birth Cohort. The women completed a computer-assisted telephone interview between December 12, 1997, and December 31, 2000, and delivered a liveborn singleton. Of these women, 1,880 gave birth preterm. Compared with those who abstained during pregnancy, the relative risks for preterm delivery among women who consumed from four to less than seven drinks and seven or more drinks per week during pregnancy were 1.15 (95% confidence interval: 0.84, 1.57) and 1.77 (95% confidence interval: 0.94, 3.31), respectively. Below these intake levels of alcohol, no increased risk of preterm delivery was found. Among women who consumed seven or more drinks per week, the relative risk of very preterm delivery was 3.26 (95% confidence interval: 0.80, 13.24) compared with that of nondrinkers. There were no differences in the associations between type of beverage and preterm delivery.