Neonatal abstinence syndrome and early childhood morbidity and mortality in Washington state: a retrospective cohort study

OBJECTIVE: To evaluate the association between neonatal abstinence syndrome (NAS) and long-term childhood morbidity and infant mortality. STUDY DESIGN: We conducted a cohort study of infants born in Washington State during 1990–2008 who were diagnosed with NAS (n=1,900) or were unexposed (n=12,283, frequency matched by birth year). Five-year hospital readmissions and infant mortality were ascertained. RESULT: Children with history of NAS had increased risk of readmission during the first five years of life relative to unexposed children; this remained statistically significant after adjustment for maternal age, maternal education, gestational age, and intrapartum smoking status (readmission rates: NAS=21.3%, unexposed=12.7%, aRR 1.54, 95% CI 1.37–1.73). NAS was associated with increased unadjusted infant mortality risk, but this did not persist after adjustment (aRR 1.94, 95% CI 0.99–3.80). CONCLUSION: The observed increased risk for childhood hospital readmission following NAS diagnosis argues for development of early childhood interventions to prevent morbidity.