Association Between Prenatal Opioid Exposure and Neurodevelopmental Outcomes in Early Childhood: A Retrospective Cohort Study

Introduction Several studies have reported increasing prevalence of prescription opioid use among pregnant women. However, little is known regarding the effects of maternal opioid use on neurodevelopmental disorders in early childhood in pregnant women with no evidence of opioid use disorders or drug dependence. Objective The aim of this study was to quantify the association between prenatal opioid exposure from maternal prescription use and neurodevelopmental outcomes in early childhood. Methods This retrospective study included pregnant women aged 12-55 years and their live-birth infants born from 2010 to 2012 present in Optum's deidentified Clinformatics (R) Data Mart database. Eligible infants born to mothers without opioid use disorders or drug dependence were followed till occurrence of neurodevelopmental disorders, loss to follow-up, or study end (December 31, 2017), whichever came first. Propensity score by fine stratification was applied to adjust for confounding by demographic characteristics, obstetric characteristics, maternal comorbid mental and pain conditions, and measures of burden of illnesses and to obtain adjusted hazard ratios (HR) and 95% confidence intervals (CI). Exposed and unexposed infants were compared on the incidence of neurodevelopmental disorders. Results Of 24,910 newborns, 7.6% (1899) were prenatally exposed to prescription opioids. Overall, 1562 children were diagnosed with neurodevelopmental disorders, with crude incidence rates of 2.9 per 100 person-years in exposed children versus 2.5 per 100 person-years in unexposed children. After adjustment, we observed no association between fetal opioid exposure and the risk of neurodevelopmental disorders (HR 1.10; 95% CI 0.92-1.32). However, increased risk of neurodevelopmental disorders were observed in children with longer cumulative exposure duration (HR 1.70; 95% CI 1.05-2.96) or high cumulative opioid doses (HR 1.22; 95% CI 1.01-1.54). Conclusion and Relevance In pregnant women without opioid use disorders or drug dependence, maternal opioid use was not associated with increased risk of neurodevelopmental disorders in early childhood. However, increased risks of early neurodevelopmental disorders were observed in children born to women receiving prescription opioids for longer duration and at higher doses during pregnancy.