Cognitive Outcomes of Preschool Children With Prenatal Cocaine Exposure

• Published in: JAMA : the journal of the American Medical Association 2004-05, Vol.291 (20), p.2448-2456
• Main Authors: Singer, Lynn T, Minnes, Sonia, Short, Elizabeth, Arendt, Robert, Farkas, Kathleen, Lewis, Barbara, Klein, Nancy, Russ, Sandra, Min, Meeyoung O, Kirchner, H. Lester
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Child Care; Child Development; Child Rearing; Child, Preschool; Clinical outcomes; Cocaine; Cocaine-Related Disorders; Cognition; Cognition & reasoning; Drug addictions; Female; Health risk assessment; Human exposure; Humans; Intelligence Tests; Longitudinal Studies; Medical sciences; Outcome and Process Assessment, Health Care; Pediatrics; Pregnancy; Pregnancy Complications; Prenatal development; Prenatal Exposure Delayed Effects; Preschool children; Toxicology
• ISSN: 0098-7484; 1538-3598
• DOI: 10.1001/jama.291.20.2448

CONTEXT Because of methodological limitations, the results of the few prospective studies assessing long-term cognitive effects of prenatal cocaine exposure are inconsistent. OBJECTIVE To assess effects of prenatal cocaine exposure and quality of caregiving environment on 4-year cognitive outcomes. DESIGN Longitudinal, prospective, masked comparison cohort study from birth (September 1994-June 1996) to 4 years. SETTING Research laboratory of a US urban county teaching hospital. PARTICIPANTS A total of 415 consecutively enrolled infants identified from a high-risk population screened for drug use through clinical interview, urine, and meconium screens. Ninety-three percent retention for surviving participants at 4 years of age resulted in 376 children (190 cocaine-exposed and 186 nonexposed). MAIN OUTCOME MEASURE The Wechsler Preschool and Primary Scales of Intelligence-Revised. RESULTS After control for covariates, prenatal cocaine exposure was not related to lower full-scale IQ (cocaine exposed [80.7] vs nonexposed [82.9]; P = .09) scores or summary verbal (cocaine exposed [79.9] vs nonexposed [81.9]; P = .11) or performance (cocaine exposed [85.5] vs nonexposed [87.5]; P = .18) IQ scores at age 4 years. However, prenatal cocaine exposure was related to small but significant deficits on several subscales (mean [SE]): visual-spatial skills (cocaine exposed [7.3 (0.22)] vs nonexposed [8.2 (0.22)]; P = .01), general knowledge (cocaine exposed [6.1 (0.18)] vs nonexposed [6.7 (0.17)]; P = .04), and arithmetic skills (cocaine exposed [6.2 (0.20)] vs nonexposed [6.8 (0.20)]; P = .05). Prenatal cocaine exposure was also associated with a lower likelihood of achievement of IQ above normative means (odds ratio, 0.26 [95% confidence interval, 0.10-0.65]; P = .004). The quality of the caregiving environment was the strongest independent predictor of outcomes. Cocaine-exposed children placed in nonrelative foster or adoptive care lived in homes with more stimulating environments and had caregivers with better vocabulary scores, and they attained full-scale and performance IQ scores (83 and 87, respectively) similar to nonexposed children in biological maternal or relative care (full-scale IQ, 82; performance IQ, 88) and higher than cocaine-exposed children in biological maternal or relative care (full-scale IQ, 79; performance IQ, 84). CONCLUSIONS Prenatal cocaine exposure was not associated with lower full-scale, verbal, or performance IQ scores but was associated wi