BACKGROUND AND PURPOSE:

• The MOTHER trial (see ‘Primary Sources – Learn More’ below) reported that infants exposed to buprenorphine, compared to methadone, experienced better outcomes
  • However, loss to follow-up and relatively small sample size in the in the trial may have falsely improved outcomes in the buprenorphine group and results may have been imprecise or possibly confounded
• Data on maternal outcomes are rare
• Suarez et al. (NEJM, 2022) assess the risks of adverse neonatal and maternal outcomes associated with the use of buprenorphine as compared with methadone in pregnancy

METHODS:

• Retrospective cohort study
  • Pregnancy cohort nested in nationwide Medicaid data
  • 2000 through 2018
  • Beneficiaries from 47 states and Washington, DC 
• Population
  • Pregnancies that ended in live births in the US insured through Medicaid from 2000 to 2018
• Exposures
  • Medication type
    • Buprenorphine
    • Methadone
  • Medication exposure time
    • Early pregnancy: Through 19 weeks
    • Late pregnancy: 20 weeks through day before delivery
    • 30 days before delivery
• Study design
  • Adjusted Risk ratio (aRR) for outcomes were adjusted for confounders with the use of propensity score overlap weights
• Primary outcomes
  • Neonatal and maternal outcomes

RESULTS:

• 2,548,372 pregnancies
  • Early pregnancy exposures
    • Buprenorphine: 10704 | Methadone: 4387
  • Late pregnancy exposures
    • Buprenorphine: 11272 | Methadone: 5056
  • Last 30 days exposures
    • Buprenorphine: 9976 | Methadone: 4587
• Neonatal abstinence syndrome occurred in fewer infants in the early exposure buprenorphine group
  • Buprenorphine: 52.0%
  • Methadone: 69.2%
  • aRR 0.73 (95% CI, 0.71 to 0.75)
• Risk for the following adverse outcomes were also significantly reduced in the buprenorphine group
  • Preterm birth
    • Buprenorphine: 14.4%
    • Methadone: 24.9%
    • aRR 0.58 (95% CI, 0.53 to 0.62)
  • Small for gestational age
    • Buprenorphine: 12.1%
    • Methadone: 15.3%
    • aRR 0.72 (95% CI, 0.66 to 0.80)
  • Low birth weight
    • Buprenorphine: 8.3%
    • Methadone: 14.9%
    • aRR 0.56 (95% CI, 0.50 to 0.63)
• There were no differences in
  • Cesarean deliveries
    • Buprenorphine: 33.6%
    • Methadone: 33.1%
    • aRR 1.02 (95% CI, 0.97 to 1.08)
  • Severe maternal complications
    • Buprenorphine: 3.3%
    • Methadone: 3.5%
    • aRR 0.91 (95% CI, 0.74 to 1.13)
• Results of exposure in late pregnancy were consistent with results of exposure in early pregnancy

CONCLUSION:

• Use of buprenorphine in pregnancy was associated with a reduced risk of adverse neonatal outcomes, compared to methadone use
• Adverse maternal outcomes were similar for buprenorphine and methadone
• The authors state

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 

Learn More – Primary Sources:

Buprenorphine versus Methadone for Opioid Use Disorder in Pregnancy

Neonatal Abstinence Syndrome after Methadone or Buprenorphine Exposure (MOTHER Trial)

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