This clinical trial compared two brief alcohol use interventions in prenatal clinics: Early Start (ES), a substance-abuse screening and treatment program integrated with prenatal care focused on abstention (n=298), and Early Start Plus (ESP), adding a computerized drink-size assessment tool and intervention focused on drinking less (n=266). Controls were untreated alcohol users (n=344). Controls had higher adverse neonatal and maternal outcome rates. Findings favored ESP for preterm labor and ES for low birth weight. No differences between ES and ESP were statistically significant. ESP provides clinicians with an innovative assessment tool that creates open dialogue about drinking during pregnancy.