Opioid use disorders (OUD) refer to non-medical uses of opioids, a class of compounds that includes heroin and opium but also includes prescribed medications such as morphine, codeine, fentanyl, oxycodone, and hydrocodone. OUD rates in the US are approximately 4.2% and evidence suggests that rates are similar in Canada. OUD during pregnancy has escalated in parallel with the epidemic observed in the general population.

In addition to the risks associated with withdrawal and relapse, pregnant women with OUD are more likely to seek prenatal care late in pregnancy, miss appointments, acquire infection, and experience poor weight gain. OUD during pregnancy also presents significant risks to the developing fetus including fetal growth restriction, fetal demise, and neonatal opioid withdrawal. Treatment goals for this population therefore aims to reduce these maternal and infant risks. Opioid agonist therapy is the standard of care for OUD during pregnancy as opioid detoxification has been associated with a high rate of relapse. As an opioid agonist, methadone has long been prescribed to pregnant women to treat OUD. More recently, buprenorphine has demonstrated similar maternal outcomes and superior neonatal outcomes in comparison to methadone. Buprenorphine is available as a monoproduct in different formulations, or as a combined formulation with naloxone, an opioid antagonist. The buprenorphine monoproducts include extended-release subcutaneous injection, sublingual, implant, transdermal, and intramuscular formulations. The buprenorhpine-naloxone combination is available as a sublingual formulation taken under the tongue in which the naloxone portion of the combination is not orally active. The combination of the opioid agonist (buprenorphine) and non-orally active antagonist (naloxone) in this formulation discourages injection use or diversion since naloxone causes severe withdrawal symptoms if the combination is injected. Buprenorphine monoproducts have been recommended during pregnancy to avoid prenatal exposure to naloxone.

The purpose of this report is to review and appraise the evidence for the clinical effectiveness, safety, and cost-effectiveness of various buprenorphine monoproducts and buprenorphine-naloxone combination formulations for UOD during pregnancy. Additionally, this report aims to review current evidence-based guidelines regarding appropriate buprenorphine formulation use for this population.