Growth failure in infants with neonatal abstinence syndrome in the neonatal intensive care unit

Objective: To assess if infants with neonatal abstinence syndrome (NAS) are smaller at birth and have decreased growth parameters between birth and discharge from the neonatal intensive care unit (NICU). Methods: Retrospective data analysis of term/late-preterm neonates with NAS at a single-center NICU between September 2006 and May 2018. Growth parameters (weight, length, HC) were measured at birth and discharge. Z scores and percentiles were calculated using WHO standard growth curves. Results: A total of 864 infants ≥35 weeks were admitted for NAS. At birth, median percentiles were weight 30%, HC 23%, and length 37%; these decreased significantly (p < 0.001) at discharge to 12%, 6.5%, and 13%, respectively. The percentage of infants <3rd percentile increased significantly (p < 0.001) in all growth parameters from birth to discharge. Conclusion: Infants with NAS are smaller at birth and have significant growth retardation in all growth parameters at discharge. An ongoing long-term growth follow-up study will discern the impact of growth restriction in NAS infants.