Objective: To establish the singular and combined occurrence of physical abuse, smoking, and substance use (i.e., alcohol and illicit drugs) during pregnancy and its effect on birth weight.

Design: Prospective cohort analysis.

Setting: Urban public prenatal clinics.

Participants: 414 African American, 412 Hispanic, and 377 white pregnant women.

Main outcome Measure(s): Occurrence of physical abuse was 16%; smoking, 29-5%; and alcohol/illicit drug use, 11.9%. Significant relationships existed between physical abuse and smoking for African American and white women. For African American women, 33.7% of women who were not abused smoked, versus 49.5% of women who were abused (χ2= 8.21; df= 1; p < 0.005). Alcohol/illicit drug use was 20.8% for nonabused women compared with 42.1% for abused women (χ2= 18.18; df=1;p< 0.001). For white women, 46.6% of women who were not abused smoked, versus 59.6% of those who were abused (χ2= 5.22; df=1;p< 0.005). As a triad, physical abuse, smoking, and alcohol/ illicit drug use were significantly related to birth weight (F[3,1040] = 30.19, p< 0.001).

Conclusions: Physical abuse during pregnancy is common, readily detected with a five-question screen, and associated with significantly higher use of tobacco, alcohol, and illicit drugs. Clinical protocols that integrate assessment and intervention for physical abuse, smoking, and substance use are essential for preventing further abuse and improving smoking and substance cessation rates.