Children with in utero cocaine exposure do not differ from control subjects on intelligence testing.

Abstract

To determine if in utero cocaine exposure affects IQ scores in children at age 4 years. A prospective, longitudinal evaluation by blinded examiners of the IQ scores of cocaine-exposed and control children of low socioeconomic status who have been observed since birth. A study center in an inner-city hospital. One hundred one children with in utero cocaine exposure and 118 control children, all of whom were 34 weeks' gestational age or older and nonasphyxiated at birth. Intelligence quotient scores on a standardized intelligence test, the Wechsler preschool and Primary Scale of Intelligence--Revised. Seventy-one cocaine-exposed and 78 control children were administered the Wechsler Preschool and Primary Scale of Intelligence--Revised. Maternal, natal, and 30-month characteristics of the children tested did not differ from those not tested. Groups did not differ on mean Performance (83.2 vs 87.0), Verbal (79.0 vs 80.8), or Full Scale (79.0 vs 81.9) IQ scores (all P > or = .10 [values for cocaine-exposed children given first]). None of these 3 scores was associated with cocaine exposure in multivariate linear regressions. Although cocaine-exposed and control groups did not differ in outcome, 93% of cocaine-exposed and 96% of control children had Full Scale IQ scores below 100, the mean IQ score for the test. In an inner-city cohort, IQ scores did not differ between cocaine-exposed and control children. However, both groups performed poorly.