The participants were all pregnant women admitted between January 1986 and December 1991 to a methadone maintenance program for opiate-addicted individuals offered through the Substance Abuse Treatment Unit of the Yale University School of Medicine Department of Psychiatry in Connecticut. Results revealed that 78 percent of the mothers reported regular use of cocaine during their pregnancy, had positive urine screens, or both. The babies who were exposed to both cocaine and methadone had significantly higher first withdrawal scores than did the other babies. However, the infants exposed to cocaine did not require more medication for management of withdrawal either in terms of dosage or in terms of the days treated. In addiction, no differences occurred in the rates of intrauterine growth retardation, prematurity, or early perinatal complications such as respiratory distress. Tables, figure, author photographs and biography, and 26 references (Author abstract modified)