Infant neurodevelopmental outcomes of prenatal opioid exposure and polysubstance use

Background: Prenatal opioid exposure has been linked to adverse birth outcomes and delays in infant development. Existing literature is limited by a simple group-differences approach as well as inadequate controls for sociodemographic factors and polysubstance exposure co-occurring with prenatal opioid use. Method: The current study assessed cumulative opioid exposure (duration of prescribed and illicit opioid use) as a predictor of infant birth outcomes and mother-reported developmental status at three and six months of age, controlling for polysubstance exposure. Participants were predominantly low-income pregnant and peripartum women, oversampled for mothers receiving medication-assisted treatment (MAT) for opioid use disorder. Prenatal opioid and non-opioid substance use were reported by mothers using a Timeline Follow-Back Interview completed during the third trimester and updated postnatally (infant age six months). Results: Developmental scores were in the normal range. However, total opioid exposure was positively related to premature birth and inversely related to mother-reported developmental status in specific domains. Associations with three-month fine motor skills and six-month communication skills were robust to controls for polysubstance exposure and sociodemographic covariates. Conclusions: Results suggest unique effects of prenatal opioid exposure on the early development of fine motor and communication skills. Similar findings were obtained for prescribed and illicit opioid use, underscoring developmental risks of both MAT and untreated substance use. Exploratory analyses investigating type and timing of MAT suggest directions for future research.