The reported frequency of alcohol abuse during pregnancy was studied in a large urban public hospital in Dallas, Texas. During 1977-1980, 5602 pregnant women were surveyed and 0.7% (95% confidence interval 0.6-0.8%) reported abusing alcohol during pregnancy. In 1987, 1.4% (95% confidence interval 1.3-1.5%) of 1032 pregnant women, who were surveyed before delivery, reported alcohol abuse according to the same definition used 10 years earlier. The increase in the frequency of reported alcohol abuse during pregnancy between 1977-1980 and 1987 is statistically significant (P less than .05).