The effects of intrauterine cocaine exposure on neurodevelopment of adopted children: The toronto adoption study

Studies of children's neurodevelopment following in utero cocaine exposure have not separated intrauterine from postnatal environmental effects because cocaine-using mothers cluster in low socioeconomic classes and have other risk factors. To over-come this limitation, we assessed physical and neurodevelopmental characteristics of 52 children, 26 adopted by parents who during the process of adoption sought counseling in the Motherisk program for parental cocaine exposure and 26 controls matched for maternal IQ, SES, and gestation age. The study group had (a) smaller head circumferences (34th versus 54th percentiles, p=0.009) but did not differ in height or weight, (b) lower McCarthy GCI scores (102.8 versus 114.2 p=0.002), (c) poorer receptive and expressive language performance on the Reynell, and (d) higher activity levels, less persistence, and increased distractibility on temperament tests. In multivariate analysis, cocaine exposure was significantly associated with lower IQ and poorer language development independent of intrauterine growth retardation and other potential confounders.