This monograph presents the proceedings of the first National Institute on Drug Abuse technical review related to the conduct of controlled studies on prenatal exposure to drugs of abuse. Papers in the monograph are categorized by session. The first session (two papers) focused on the detection and quantification of prenatal drug exposure in infants, including studies of the effects of smoking and of pharmacokinetic correlates of fetal drug exposure. The second session (three papers) explored assessments of pregnancy outcomes, including discussions of the implications of previous research methodologies on future research; definitional problems in cocaine research; and the use of birth defect monitoring programs for assessing the effects of maternal substance abuse. Assessment of the status of the newborn, including studies on neurobehavioral organization, cardiorespiratory functioning, and brain development, was considered in the four papers presented in the third session. The fourth session (three papers) offered a framework for measuring drug-induced physical and behavioral delays and abnormalities, including both clinical and psychophysiologic perspectives. The next two sessions (with two and three papers respectively) focused on specific types of behavioral delays and abnormalities, covering cardiac and respiratory control, endocrine function, monoamine systems, behavioral development, nonhuman primate models, learning and cognition, and social and emotional development. The final session focused on tracking drug effects over the lifespan, and includes three papers on research challenges for following exposed infants into childhood, patterns of growth and development in narcotic-exposed children, and the integrity of psychopathology diagnoses across the lifespan. Each session concluded with a discussion paper highlighting study findings, methodological issues, and research problems and needs. (AC)