A Trial to Determine Weight Gain Benefits of Caloric Supplementation for NAS Infants

Infant Inclusion Criteria: * Infants with NAS born to mothers age 18-45 with methadone exposure before or during pregnancy who do not intend to place their infants for adoption * Infants \> 2200 g Infants at least 36 weeks gestational age * Delivered at: Yale New Haven Hospital * Mothers/infants able to return to outpatient pediatric provider for 2 month and 4 month weights visits Infant Exclusion Criteria: * Infants with major congenital malformations * Infants enrolled to NICU \>24 hours for medical conditions other than NAS treatment before 3 days of life Mother's Inclusion criteria - * Pregnant women (age 18-45) who have started methadone treatment at obstetrics or other YNHH appointments * Confirm methadone treatment is received from a licensed treatment program * Confirm that mothers are planning to deliver their infant(s) at Yale New Haven Hospital * Confirm that mothers do not intend to place the infant(s) for adoption * Confirm mother's willingness to participate in the study (including attending the 2-month and 4-month follow up weigh-ins with pediatrician) * Consent forms will be signed and faxed to study staff