ABSTINENCE SYNDROME (NAS) MONA PRASAD, SUSIE LIM, DEBRA GARDNER, LEANDRO CORDERO, PHILIP SAMUELS, Ohio State University, Department of Obstetrics and Gynecology, Columbus, Ohio, The Ohio State University, Department of Obstetrics and Gynecology, Columbus, Ohio, Ohio State University, Department of Pharmacy, Columbus, Ohio, Ohio State University, Department of Pediatrics, Columbus, Ohio OBJECTIVE: To evaluate the effects of HDMM on NAS. STUDY DESIGN: The amount of methadone required for maintenance of opiate-addicted patients during pregnancy is increasing. Many patients require maintenance doses of 100 mg per day at term. The neonatal effects HDMM has not not been investigated. We employed a retrospective chart review, 2002-present, of all infants with antenatal methadone exposure to examine the effect of HDMM on NAS. RESULTS: 72 infants were identified to have antepartum methadone exposure. The avg maternal methadone daily dose 101 / 50mg; avg length of stay (LOS) 23.9 / 16 days; avg days requiring meds for NAS 19 / 14 days. 6 babies required medication upon discharge. The most common neonatal complication was jaundice (n 12). When comparing lower dose methadone with higher dose methadone, no statistically significant differences were identified in LOS or days on meds for NAS. We do identify a statistically significant difference in EGA and birthweight. Similar results were identified when comparing the extremes ( 50 mg vs 150 mg) of dosing as well. Breastfed infants have fewer days of medications for NAS versus bottle-fed infants (17 vs 25, p 0.06). CONCLUSION: NAS appears to be dependent on more than degree of dosing alone. Perhaps specific pharmacokinetics/pharmacodynamic parameters warrant investigation to understand NAS fully. Breastfeeding should be considered in women on methadone maintenance, regardless of dose. This study suggests that aggressive treatment of addiction with HDMM may contribute to an environment conducive to prolongation of pregnancy, which may be beneficial to the neonate in terms of avoidance of neonatal comorbidities.