Objective: Quantify the effect of prenatal polysubstance exposure on neonatal outcomes compared to methadone exposure alone.
Study design: This retrospective cohort study compared infants with methadone-only exposure to methadone with additional psychoactive substances. Outcomes included time to maximum Finnegan scores, proportion requiring scheduled morphine, and length of stay (LOS).
Results: We identified 323 subjects. The median time to maximum Finnegan score was 38.0 h with 94% peaking within 96 h. Forty-five percent of methadone-only infants were started on scheduled morphine compared to 54% of polysubstance infants (p = 0.10). LOS for polysubstance-exposed infants was 1.30 times longer than infants with methadone-only exposure (95% confidence interval: 1.05, 1.60).
Conclusions: Exposure to methadone with additional psychoactive substances is associated with longer LOS, but not postnatal morphine use or peak withdrawal symptoms. Most infants experience peak withdrawal symptoms within 4 days and may not benefit from longer observation.