The impact of prenatal cocaine exposure: studies of the developing infant.

This article traces several major phases of research evaluating the development of infants exposed to cocaine. Although initial studies focused on the medical neurobehavioral status of the neonate, these studies often lacked appropriate comparison groups, attention to polydrug use, and follow-up after hospital discharge. As studies began to include longer follow-up periods and the types of comparison groups necessary to evaluate the unique effects of cocaine versus factors such as poverty and polydrug use, the deleterious effects of cocaine exposure were not as apparent. Although most early studies focused only on mental and motor outcomes, recent studies evaluating learning processes, emotional development, and the effects of cocaine-exposed infants' unique caretaking environments may provide more detailed descriptions of the outcomes of this growing population. This article discusses numerous methodological issues that continue to challenge this complex research area and recent research efforts that may prove beneficial in guiding future studies.