Pregnancy and Perinatal Outcomes Following Exposure to Medications for Opioid Use Disorder: An Analysis of FAERS (FDA Adverse Event Reporting System)

OBJECTIVES: The opioid epidemic in the United States has seen an increase in opioid use, even during pregnancy. Methadone and buprenorphine are currently approved for treating opioid use disorder in pregnancy. These medications have been reported to be associated with neonatal abstinence syndrome, low birth weight, and premature delivery. This study aims to examine and compare FAERS reports related to the use of methadone, buprenorphine, buprenorphine-naloxone, and naloxone during pregnancy, thus assessing their comparative safety.

METHODS: The FAERS database was searched for adverse events (AEs) related to the use of methadone, buprenorphine, buprenorphine-naloxone, and naloxone. AEs reported over a five-year period from the first quarter of 2019 to the third quarter of 2023 were included. The AEs were coded using Medical Dictionary for Regulatory Activities (MedDRA) Preferred Terms (PTs), and the findings were presented using descriptive statistics.

RESULTS: The study analyzed 10,110 cases, identifying 735 pregnancy-related cases with 1,718 reactions. Buprenorphine had a higher incidence of serious reports (64.3%), compared to methadone (33.3%). Despite a higher number of cases reported with methadone (412 vs. 311 for buprenorphine), buprenorphine was linked to a higher rate of neonatal mortality and more reports of neonatal drug withdrawal syndrome. These findings challenge previous literature which suggested buprenorphine had less serious neonatal outcomes compared to methadone.

CONCLUSIONS: While medications for opioid use disorder are linked to adverse outcomes, these risks are less severe than those arising from untreated opioid use disorder. It is important to patients about potential outcomes, but this should not deter individuals from seeking treatment. Further research is necessary to determine if any of the currently recommended medications are preferable in specific contexts.