Infants born to opioid-dependent women in Ontario, 2002-2014

Background — There is a paucity of data characterizing mother-infant pairs with prenatal opioid dependence in Canada. We therefore conducted a study of relevant births in Ontario from 2002 to 2014.

Methods — We used data from the Institute for Clinical Evaluative Sciences, the linked databases of coded population-based Ontario health services records. Differences in characteristics of opioid-dependent mother-neonate pairs and infant hospital costs by year were assessed using linear regression, and we calculated rates of preterm birth, low birth weight, birth defects, mortality, and neonatal abstinence syndrome. 

Results — The number of infants born to opioid-dependent women in Ontario rose from 46 in 2002 to almost 800 in 2014. Methadone was most frequently used for prenatal opioid dependence; there was little buprenorphine or buprenorphine + naloxone use. Rates of preterm birth and low birth weight were high. The proportion of neonates with neonatal abstinence syndrome (58%) was stable over the study period. The mean length of neonatal hospital stay was 13.96 days. Infant hospital costs increased from $724 774 in 2003 to $10 539 988 in 2013, and the mean cost per infant grew from $9928 to $12 917. Birth defect prevalence was 75.84/1000 live births (95% CI 68.12/1000 to 84.10/1000). The stillbirth rate was 11.39/1000 births (95% CI 8.47/1000 to 14.99/1000), and the infant mortality rate was 12.21/1000 live births (95% CI 9.16/1000 to 15.95/1000).

Conclusion — We observed a 16-fold increase in the number of mother-infant pairs affected by opioid dependence in Ontario over the past decade. Adverse birth outcome rates were high. Expanded services for opioid-dependent women and their children are needed.