Salivary transcriptomic study to understand the molecular effects of feeding dysregulation in opioid-exposed neonates...

ObjectivesTo evaluate the effects of maternal opioid use on the expression of hypothalamic/reward genes involved in feeding regulation in late preterm neonates. We hypothesize that opioid use, rather than prematurity alone, is associated with feeding dysregulation and the need for tube feeding in this late preterm population.Study DesignIn this prospective, observational pilot study, the need for tube feeding was determined from subjects' medical records. The study population consisted of 39 opioid-exposed and 36 non-exposed neonates born at 34-37 weeks' gestation (late-preterm). Saliva was collected within 48 h of birth from the selected neonates; using RNA extraction and qPCR, the saliva was analyzed for select hypothalamic/reward and inflammatory genes involved in feeding regulation. The need for tube feeding (primary outcome) and salivary gene expression data (secondary outcome) were compared between the opioid-exposed and non-opioid exposed. Maternal and neonatal characteristics associated with increased need for tube feeding were explored using descriptive analyses.ResultsA significantly greater proportion of the opioid-exposed late preterm cohort, compared to non-exposed neonates, required tube feeding (51.2% vs 22.2%, p < 0.01). Opioid-exposed neonates also had lower expression of anorexigenic gene POMC (ΔCt 15.44 ± 2.76 vs 13.84 ± 4.03, p = 0.054), and this was accompanied by greater milk consumption in the first week of life (average of 24.2 mL/kg/day). Male sex, withdrawal severity, maternal polysubstance, and methadone use were associated with increased need for tube feeding.ConclusionModulation of hypothalamic/reward and inflammation genes may contribute to the need for tube feeding and its associated risks in opioid-exposed late preterm neonates.