Objective: To estimate the incidence of physical and sexual abuse in a sample of adult and adolescent pregnant women and to determine the relationship between abuse and maternal complications and infant birth weight. Methods: One thousand eight hundred ninety-seven women were screened for abuse during pregnancy. Maternal complications and infant birth weight were obtained by record review. Results: Physical abuse in the past year and/or during pregnancy was reported by 37.6% of the adolescent and 22.6% of the adult women (P < .001). Abused adult women were more likely to have unplanned pregnancies (P < .001) and to begin care after 20 weeks (P < .01) than nonabused women. For the aggregate sample of 1597 for whom birth weights were available, abuse was a significant risk factor for low birth weight (LBW) (P < .05) as was poor obstetric history (P < .05). Using Institute of Medicine risk factors for LBW, abused adults were more likely to have poorer past obstetric histories and to use tobacco, alcohol, and drugs (P < .05). Abused adolescents were at greater risk for smoking and first- or second-trimester bleeding (P < .05). For the aggregate, abused women were at greater risk for poor obstetric history, vaginal/cervical infection during pregnancy, smoking, and alcohol and drug use. Conclusion: More than one-third of the adolescent and nearly one-fourth of the adult women reported abuse in the past year and/or during pregnancy. Abuse is related to poor obstetric history, substance use, and LBW. The short abuse assessment screen detects potential abuse in order that interventions can be implemented.