Incidence of Faltering Growth in Infants With Neonatal Opioid Withdrawal Syndrome.

Objective: Infants with neonatal opioid withdrawal syndrome (NOWS) often experience excessive weight loss while in the hospital after birth. However, the growth patterns of these infants after hospital discharge are not well understood. We aimed to examine the incidence of faltering growth during the first 4 months of life.

Methods: We used electronic health records data to conduct a retrospective matched cohort analysis of infants with and without NOWS born at 2 community hospitals between 2016 and 2019. International Classification of Diseases, Tenth Revision billing codes were used to identify the exposed cohort. Exposed infants with NOWS were matched 1:3 with unexposed infants based on gestational age (+/- 6 days), sex, and birthweight (+/- 100g). Our primary outcome was faltering growth, estimated by logistic regression.

Results: We identified 176 exposed and 498 nonexposed infants who met the inclusion criteria. In the exposed cohort, 48% (n = 85) received formula during birth hospitalization, 31% (n = 54) were prescribed increased caloric fortification, and 20% (n = 35) were discharged home on fortified feeds. The average weight loss in exposed infants during birth hospitalization was 7% below birth weight. During the first 4 months of life, 21 out of 176 (12%) infants with NOWS developed faltering growth, with a resulting odds ratio of 1.14 (95% CI 0.65, 1.92) compared with nonexposed infants.

Conclusion: We did not observe an increased incidence of faltering growth in infants with NOWS during the first 4 months of life. Additional research is needed to identify which infants with NOWS are at risk for developing faltering growth.