Singer, L. T., Minnes, S., Short, E., Arendt, R., Farkas, K., Lewis, B., et al. (2004).Journal of the American Medical Association, 291, 2448-2456.

The evidence of prenatal cocaine effects on fetuses and newborns is well documented. Cocaine readily crosses placental and fetal brain barriers and affects the developing fetal brain. This study adds to the growing body of research that assesses the long-term effects of prenatal cocaine exposure on preschool and school age children.

Infants were identified for inclusion in the study through clinical interview, urine, and meconium screens from a population at high risk for drug use. Children were followed for 4 years (93% retention rate), resulting in 376 children (190 cocaine-exposed and 186 non-exposed). The children were given a standard IQ test by researchers unaware of their cocaine status. Children from exposed and non-exposed groups had similar overall IQ scores, as well as summary verbal and performance scores. Cocaine-exposed infants had slightly lower information, arithmetic, and object assembly scores than non-exposed kids. Arithmetic skills were negatively affected in boys only, indicating (as in other studies) that boys may be differentially vulnerable. The quality of the caregiving environment was the strongest independent predictor of all outcomes, that is, cocaine-exposed children who lived in homes with more stimulating environments and with caregivers who had better vocabulary scores and lower psychological distress had better outcomes.

So what do we make of all of this? Previously, most of our interventions have focused on intrauterine cocaine exposure (identifying drug-using mothers and immediate treatment for exposed babies). The findings of this study help us to understand that what happens outside the uterus can mitigate or compensate for cocaine's intrauterine effects. The take-home message is clear: drug treatment and resource investment both prenatally and postnatally are essential to maximize the well being of women and children in these families.

Comment by Linda Beth Tiedje