SLEEP DISORGANIZATION IN COCAINE-EXPOSED NEONATES

The purpose of the study was to examine the effect of prenatal cocaine exposure on infant sleep and wakefulness. Four-hour recordings of sleep and wakefulness were obtained from 17 cocaine-exposed neonates and 14 control infants at 2 weeks of age. Each 1-min epoch was classified as quiet sleep, active sleep, indeterminate sleep, or waking based on eye and body movements and respiratory variability. Analyses of variance were performed on durations of total sleep versus wakefulness, and quiet sleep, active sleep, and indeterminate sleep. The cocaine-exposed infants showed proportions of sleep and wake time similar to those of the control infants. Sleep time was, however, distributed differently among the various sleep states in the cocaine-exposed infants. Infants with prenatal cocaine exposure showed significantly more indeterminate sleep and significantly less active sleep than the control infants, even when confounding variables were controlled statistically. Regression analyses indicated that infrequent cocaine use paradoxically increased indeterminate sleep time to a greater extent than frequent use, possibly due to differences in patterns of cocaine use or recency of exposure. These results suggest that active sleep is less organized at 2 weeks of age in infants of cocaine-abusing mothers than in infants without cocaine exposure.