Prenatal cocaine and other substance exposure: effects on infant autonomic regulation at 7 months of age.

This study examined the association between prenatal exposure to cocaine and autonomic regulation at 7 months of age. Heart rate (HR) and respiratory sinus arrhythmia (RSA) were obtained from 154 (79 exposed, and 75 nonexposed) infants during baseline and tasks designed to elicit positive and negative affect. Cocaine-exposed infants had higher HR during the positive affect task. There was a significant suppression of RSA during the negative affect task for nonexposed infants but not for exposed infants. Fetal growth and maternal caregiving behavior did not mediate or moderate this association. These results provide additional support for an association between prenatal cocaine exposure and dysregulation during infancy. (c) 2007 Wiley Periodicals, Inc.