418 - Characteristics and Outcomes of Neonatal Opioid Withdrawal Syndrome in Preterm Infants: A Retrospective Cohort Study in the Current Era

Poster Number: 418
Publication Number: 418.136

Alicia Heyward, UH Rainbow Babies & Children's Hospital, Willoughby, OH, United States; Nori M. Minich, Case Western Reserve University School of Medicine, Cleveland, OH, United States; Anna Maria Hibbs, UH Rainbow Babies & Children's Hospital, Cleveland, OH, United States; Adriana C. Hoffman, UH Rainbow Babies & Children's Hospital, Cleveland, OH, United States; Lulu Zhao, Case Western Reserve University School of Medicine, Cleveland, OH, United States; Moira Crowley, UH Rainbow Babies & Children's Hospital, Cleveland, OH, United States

Background: The incidence of Neonatal Opioid Withdrawal Syndrome (NOWS) has increased exponentially in the last decade. Characteristics of NOWS have been well described in term infants, but data is lacking in preterm infants. The few existing studies reflect neonates born early in the opioid epidemic and likely do not reflect current prenatal exposures including fentanyl and polysubstance or polydrug use.

Objective: Describe symptomatology, presentation and treatment of NOWS in preterm (PT) and late preterm (LPT) infants compared to term infants.

Design/Methods: This is an IRB approved, retrospective chart review of infants admitted to a single tertiary care center between 2014 and 2019. Infants were identified using a unit database and medical record search with ICD-9 and 10 codes. Infants were categorized by gestational age: term (>37 weeks), LPT (34 0/7 to 36 6/7 weeks) and PT ( < 34 weeks). Inclusion criteria: all infants admitted in first 7 days of life with history of prenatal opioid use and/or positive maternal or infant toxicology screen. Exclusion criteria: received opioids prior to transfer or for treatment other than NOWS, Grade 3-4 intraventricular hemorrhage, neonatal encephalopathy, and central nervous system anomalies. Modified Finnegan Scores used to assess withdrawal symptoms and analysis performed on scores from time of admission.

Results: 263 infants met criteria; 13 PT, 72 LPT, and 178 term infants. A similar onset (46 vs 51.2 hours) and peak NOWS symptoms (52.4 vs 67.1 hours) was seen in LPT and term infants. Highest total Finnegan scores were lower for LPT infants compared to term (9 vs 12), with LPT infants scoring less frequently for increased muscle tone (85.5 vs 96.6%), excoriations (18.8 vs 34.5%), and fever (63.8 vs 91.2%). PT and LPT infants received less pharmacologic treatment compared to term (23.1 and 44.4 vs 66.3%). Duration of treatment (13.1 vs 12.1 days), adjunctive medication use (18.8 vs 16.1%), and maximum morphine dose was similar in LPT and term infants.Conclusion(s): Understanding the timing and presentation of NOWS in LPT infants is important as discharge can occur in the first few days of life. The onset of NOWS in LPT infants were similar to term, allowing for the same duration of monitoring for withdrawal. PT and LPT infants received less pharmacologic treatment and exhibited lower CNS, ANS and overall Finnegan scores compared to term. We hypothesize this is related to the infants’ physiologic immaturity, as suggested by previous investigators, but also brings to question the current opioid withdrawal scoring tools’ ability to accurately assess NOWS in preterm infants.