The Maternal Lifestyle Study: Cognitive, Motor, and Behavioral Outcomes of Cocaine-Exposed and Opiate-Exposed Infants Through Three Years of Age

Objective. To evaluate the direct effects of prenatal cocaine exposure and prenatal opiate expo- sure on infant mental, motor, and behavioral outcomes longitudinally between 1 and 3 years old. Methods. As part of a prospective, longitudinal, mul- tisite study, the Bayley Scales of Infant Development II were administered to 1227 infants who were exposed to cocaine (n 474), opiates (n 50), cocaine and opiates (n 48), and neither substance (n 655) at 1, 2, and 3 years of corrected age by certified, masked examiners. Hierar- chic linear modeling of the 1-, 2-, and 3-year scores was conducted using cocaine and opiate exposure as predic- tors with and without controlling for covariates. Results. Overall retention was 88.4% and did not dif- fer by cocaine or opiate exposure. Overall (at 1, 2, and 3 years), cocaine-exposed infants scored 1.6 Mental Devel- opment Index points below infants who were not ex- posed to cocaine. Opiate-exposed infants scored 3.8 Psy- chomotor Development Index points below infants who were not exposed to opiates. Neither the cocaine nor the opiate effect remained significant after controlling for covariates. Neither cocaine nor opiate exposure was as- sociated with the Behavioral Record Score during the examination. Low birth weight and indices of nonopti- mal caregiving were associated with lower Mental De- velopment Index, Psychomotor Development Index, and Behavioral Record Score scores for all groups of infants. Conclusions. In the largest at-risk sample observed longitudinally to date, infant prenatal exposure to co- caine and to opiates was not associated with mental, motor, or behavioral deficits after controlling for birth weight and environmental risks. Pediatrics 2004;113: 1677-1685; cocaine, opiates, prenatal exposure, BSID-II, outcome.