Grant: Project Grant

Opioid use in pregnancy poses a significant public health risk for both parents and their children. At present, greater than one third of admissions to substance use programs in pregnancy in Ontario are opioid-related. Methadone (a full opioid agonist) was the traditional pharmacotherapy for the treatment of opioid use disorder (OUD) in pregnancy. However, buprenorphine/naloxone (Suboxone; a partial opioid agonist) is gradually replacing it in many areas of the world. Suboxone has potential benefits over methadone in pregnancy including easier administration (with take-home doses), less need for dose adjustment, and lower overdose risk. There may be additional advantages for the newborn child including less severe neonatal abstinence syndrome. While these are all advantages for pregnant patients and their children, rates of treatment retention for opioid agonist therapy (OAT) and risks of serious opioid related adverse events (e.g., opioid overdose, opioid-related death) specifically during pregnancy and the postpartum period are not well defined. Since there will not be adequately powered randomized trials to guide OUD treatment recommendations in pregnancy, we rely on real-world safety and effectiveness data to examine key maternal, obstetrical, and neonatal outcomes among those prescribed OAT during pregnancy. Using linked health care databases in Ontario, we will conduct a series of studies comparing individuals prescribed Suboxone to methadone in pregnancy. These studies will represent some of the largest, and most comprehensive, using real-world population-based data to examine OAT in pregnancy and postpartum. Findings from these studies will inform the treatment of perinatal opioid use disorders in Canada and more broadly, help to update guidelines on the treatment of substance use disorders in pregnancy, and contribute to the improved care of countless pregnant individuals living with OUD.