Buprenorphine in pregnancy is associated with lower neonatal risk than methadone

1. The current cohort study found that buprenorphine for treating opioid use disorder during pregnancy was associated with lower neonatal risk than methadone.

2. The risk of adverse maternal outcomes was similar between buprenorphine and methadone recipients.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Opioid use disorder is a public health issue, and its prevalence in pregnant persons has risen steadily. The standard of care for treating opioid use disorder during pregnancy is either methadone or buprenorphine. Methadone must be administered in person in regulated settings, whereas buprenorphine can be self-administered by the patient once prescribed. Buprenorphine has also shown superior neonatal outcomes in small studies. The current cohort study examined data from pregnant persons enrolled in public insurance programs across the United States to compare outcomes between buprenorphine and methadone recipients. Compared to methadone, buprenorphine was associated with a lower risk of adverse neonatal outcomes, such as abstinence syndrome, preterm birth, and lower birth weight. Conversely, maternal risks were comparable between these medications. Exposure time during pregnancy did not impact the risk profile. Study limitations included restrictions due to the focus on Medicaid-covered individuals only and the lack of dosing information. Nevertheless, the large cohort being studied demonstrated that buprenorphine may be more favorable for neonatal outcomes than methadone to treat opioid use disorder during pregnancy.

Click here to read the study in NEJM

In-Depth [retrospective cohort]: This cohort study compared the outcomes of treating opioid use disorder in pregnancy with buprenorphine versus methadone. The cohort comprised pregnant persons aged 12 to 55 with live births and Medicaid coverage. Buprenorphine or methadone exposure was stratified into early (last menstrual period to gestational week 19) or late (gestation week 20 to the day before delivery) pregnancy. Neonatal outcomes included neonatal abstinence syndrome, preterm birth, small size for gestational age, and lower birth weights. Maternal outcomes included cesarean section and severe maternal complications that were potentially life-threatening. Overall, 2,548,372 pregnancies were examined. In early pregnancy, there were 10,704 buprenorphine exposures and 4,387 methadone exposures compared to 11,272 buprenorphine exposures and 5,056 methadone exposures recorded in late pregnancy. Neonatal abstinence syndrome occurred in 52.0% and 69.2% of infants exposed to buprenorphine and methadone, respectively, in the 30 days before delivery (Adjusted Relative Risk [ARR], 0.73; 95% Confidence Interval [CI], 0.71 to 0.75). Further, 14.4% of infants exposed to buprenorphine in early pregnancy were born preterm, compared to 24.9% of those exposed to methadone (ARR, 0.58; 95% CI, 0.53 to 0.62), 12.1% and 15.3% were small for gestational age (ARR, 0.72; 95% CI, 0.66 to 0.80), and 8.3% and 14.9% had low birthweight (ARR, 0.56; 95% CI, 0.50 to 0.63). The risks of adverse maternal outcomes were comparable between buprenorphine and methadone. These results provided real-world evidence from a large cohort that buprenorphine may provide favorable neonatal outcomes when used to treat opioid use disorder during pregnancy compared to methadone.

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