Symptoms of Neonatal Abstinence Syndrome (NAS) can be attributed largely to dysfunction of the autonomic nervous system in opiate exposed neonates. Vagal tone is a readily available measure of autonomic nervous system functioning. NAS is a widely variable disorder with poorly understood pathophysiology; while all opiate exposed infants will exhibit some signs and symptoms of NAS, only approximately ½ have severe enough symptoms to require pharmacologic therapy. This research seeks to determine the relationship between infant vagal tone and NAS severity. The determination of a link between newborn vagal tone and NAS severity could result in the prediction of infants at risk for severe NAS and provide these infants and mothers with intensified services and early treatment, thereby shortening the course of NAS in the infant.

Consecutively born methadone exposed infants had hert period and cardiac vagal tone measurements extracted via standard EKGs on days 1 and 3 of life. The infant's NAS course was assessed serially.

Inclusion Criteria:

• Term infant (>= 37 weeks by 1st or second trimester sonogram),
• In utero opiate exposure (either heroin or methadone) requiring a minimum of three day infant hospitalization after birth
• Delivery to a client active in drug abuse treatment

Exclusion Criteria:

• Significant medical complications in the infant
• Circumcision within 24 hours of the proposed EKG/vagal tone measurement (circumcision has been found to affect vagal tone)
• Infant hospitalization in the Neonatal Intensive Care Unit (NICU)
• Psychiatric impairment of the mother such that informed consent is not possible

Drug exposed infants