Buprenorphine May Be Preferred Over Methadone for Use During Pregnancy

During pregnancy, buprenorphine use was associated with a lower risk for adverse neonatal outcomes compared with methadone, according to results of a study published in The New England Journal of Medicine.

Investigators from Brigham and Women’s Hospital sourced data for this study from nationwide Medicaid databases collected between 2000 and 2018. Pregnancies resulting in live births among girls or women aged 12 to 55 years (N=2,548,372) with use of buprenorphine or methadone during the pregnancy were evaluated for pregnancy and neonatal outcomes. A total of 10,704 and 11,272 of pregnancies were exposed to buprenorphine, and 4387 and 5056 to methadone during early (last menstrual period to gestational week 19) and late (gestational week 20 to delivery) pregnancy, respectively.

In a weighted cohort of 2477 buprenorphine and methadone users, pregnant girls or women had a mean age of 28.6 years, 82.5% were White, 70.4% used any opioid agonist prepregnancy, 29.9% had anxiety, 26.5% depression, 10.9% bipolar disorder, 34.9% used antidepressants, 32.7% prescription opioids, 18.6% benzodiazepines, and 44.2% had an inadequate Prenatal Care Utilization Index.

Neonatal abstinence syndrome, defined as buprenorphine or methadone exposure within 30 days of delivery, occurred in 52% of infants born to buprenorphine users compared with 69% those born to methadone users.

Among the cohort with buprenorphine and methadone use in early pregnancy, the rates of preterm birth were 14.4% and 24.9%, small size for gestational age were 12.1% and 15.3%, low birth weight were 8.3% and 14.9%, cesarean section delivery were 33.6% and 33.1%, and severe maternal complication were 3.3% and 3.5%, respectively. Similar rates were observed among the groups with use in late pregnancy.

Buprenorphine use was associated with decreased risk for neonatal abstinence syndrome (adjusted relative risk [aRR], 0.73), preterm birth with early (aRR, 0.58) or late (aRR, 0.57) use, small size for gestational age with early (aRR, 0.72) or late (aRR, 0.75) use, and low birth weight with early (aRR, 0.56) or late (aRR, 0.56) use compared with methadone. Similar trends were observed in subgroup analyses.

This study may have included selection bias by excluding pregnancies that did not result in a live birth.

Study authors concluded, “Any opioid agonist therapy is recommended over untreated opioid use disorder during pregnancy, because untreated persons have greater incidence of adverse outcomes owing to withdrawal, return to opioid use, overdose, intravenous drug use, and inadequacy of prenatal care. Results of our study using a large, national database of Medicaid beneficiaries showed that buprenorphine treatment for opioid use disorder during pregnancy was associated with more favorable neonatal outcomes than methadone treatment.”

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.