The 1984-87 Boston City Hospital Maternal Health Habits Project was conducted as part of an ongoing study of maternal health behaviors, psychosocial characteristics, and pregnancy outcomes. The study was designed to investigate the effects on infants of various prenatal factors, including the use of alcohol, cigarettes, and illicit drugs; violence; emotional well-being; social support; and life experiences.

Subjects were continuously recruited from the Women's and Adolescent Prenatal Clinics of Boston City Hospital from July 1984 through June 1987. English- and Spanish-speaking women who were willing to give informed consent and who gave birth by December 31, 1987 were eligible to participate in the study.

Participants were interviewed at least twice — once during the prenatal period at the time of registration in the study and again during the immediate postpartum period. A subset of the participants were also interviewed at 32 to 36 weeks into the pregnancy. Prenatal and postpartum interviews obtained information on patterns of use of cigarettes, alcohol, marijuana, cocaine, and psychoactive drugs; participants' demographic and psychosocial characteristics; and participants' reproductive and general medical histories. Also, at the time of interviews, participants submitted urine samples to be used for drug testing. After delivery, information documenting reproductive and medical histories, prenatal and intrapartum risk factors, and weight gain during pregnancy was abstracted from mothers' medical records. Infants were examined within 8 to 72 hours of delivery by a physician who was blinded to the mothers' prenatal histories.