NEUROMOTOR DEVELOPMENT OF COCAINE-EXPOSED AND CONTROL INFANTS FROM BIRTH THROUGH 15 MONTHS - POOR AND POORER PERFORMANCE

Objective. The objective of this study is to describe the longitudinal course of motor development of a group of infants exposed to cocaine in utero and an unexposed control group. Methods. Subjects included 28 in utero-exposed infants and 22 unexposed infants matched for race, i ncome of the family, and mother's educational level. Infants were eval uated at 1 month with the Alberta Infant Motor Scale (AIMS), at 4 mont hs with the AIMS and Movement Assessment of Infants (MAI), at 7 months with the AIMS and MAI, and at 15 months with the Peabody Developmenta l Motor Scales (PDMS). Results. At 4 months, compared with the unexpos ed infants, a significantly larger proportion of the exposed infants f ell below the 50th percentile on the AIMS and had greater proportion o f suspicious risk scores on the IMAI. At 7 months infants in the expos ed group had lower AIMS and MAI scores than the control group. There w as no difference between groups on the motor scales at 1, 4, or 15 mon ths. At all ages more infants in both groups scored significantly less than the expected norms on all scales. Performance was unrelated to a cumulative risk index made up of demographic, medical, and social fac tors. Almost all subjects had risk scores that placed them at extremel y high levels of risk. Performance may have been related to a differen ce in weight between groups at 7 months and to decreasing weights for both groups by 15 months. Conclusion. In utero cocaine exposure has a significant, although relatively small, effect on infant motor perform ance late in infancy. However, regardless of exposure status, these in fants had poor performance that may be accounted for by a heavy accumu lation of risk factors associated with poverty.