TITLE: Gestational Age Alters Assessment of Neonatal Abstinence Syndrome
Background: Neonatal Abstinence Syndrome (NAS) due to maternal opioid use affects both term and preterm infants, however the relationship between gestational age and clinical symptomatology is still poorly understood. Currently used assessment tools such as modified Finnegan scoring as well as management strategies for NAS are similar in term and preterm infants. We hypothesized that preterm infants would have a different symptomatology than term infants with NAS due to maternal opioid use and this would lead to reduced modified Finnegan scores.
Objective: To compare clinical features and outcomes of NAS in infants admitted to the NICU based on gestational age groups: Preterm (32 - 36 6/7 weeks) and term (37 weeks or older).
Design/Methods: Retrospective data analysis using medical records of infants with a diagnosis of NAS admitted to the neonatal intensive care unit of a regional perinatal center between 2017 and 2020. An exclusion criteria was applied for patients that had 1) concern for NAS by history, but did not demonstrate enough symptomatology to be scored or 2) a significant co-morbidity that would interfere with accurate NAS scoring such as any respiratory support more than nasal cannula. A modified Finnegan scoring system was used based on 3 different symptomology categories including CNS, GI and Other.
Results: Out of 112 infants with a diagnosis of NAS secondary to maternal opioid use admitted to the NICU, 42 (37.5%) were preterm and 70 (62.5%) were term. Demographics characteristics are represented in Table 1. Average and maximum NAS scores were significantly higher in the term infants (Table 2). A weak correlation is noted between gestational age and average as well as maximum NAS scores (Fig 2). Although both populations experienced comparable rates of CNS symptoms, term infants were more likely to experience GI and Other symptom categories during their NAS course. Term infants were more likely to require pharmacological treatment with morphine, though this did not reach statistical significance. Average duration of morphine therapy was similar in both groups. Total hospital stay was longer in preterm infants, which is likely due to gestational age and co-morbidities. Both preterm and term infants that had maternal breast milk incorporated into their diet were less likely to require morphine therapy (Fig 2).
Conclusion(s):
This data suggests that preterm infants with NAS are more likely than their term counterparts to have lower NAS scores by conventional scoring methodologies. Newer NAS assessment modalities such as Eat, Sleep, Console (ESC) may overcome some of the challenges of the traditional scoring systems, but will require validation in preterm infants. This study also further reinforces the importance of encouraging MBM feeds in infants with NAS regardless of gestational age.
