Clinical Pearls & Morning Reports
Published November 30, 2022
Suarez et al. assessed the risks of adverse neonatal and maternal outcomes associated with the use of buprenorphine as compared with methadone in pregnancy in a large U.S. cohort in which there was careful control for confounders. Read the NEJM Original Article here.
Q: Is the prevalence of opioid use disorder increasing among pregnant women?
A: The prevalence of opioid use disorder among pregnant persons has increased steadily in the United States since 2000. As of 2017, approximately 8.2 per 1000 deliveries were estimated to be affected by opioid use disorder nationwide, with a particular burden in the population that was insured by Medicaid. The standard care for treating pregnant persons with opioid use disorder is opioid agonist therapy with buprenorphine or methadone, which is associated with improved adherence to prenatal care, lower incidence of preterm birth, reduced return to opioid use, and fewer instances of opioid overdose and death from opioid overdose.
Q: How do buprenorphine and methadone differ?
A: Buprenorphine and methadone have important differences. Methadone is a full agonist with high intrinsic activity at mu-opioid receptors, whereas buprenorphine is a high-affinity partial agonist with low intrinsic activity. Methadone is administered during daily in-person visits to federally regulated opioid treatment programs. Buprenorphine can be prescribed by approved providers, which allows patients to administer the medication themselves.
A: Results of this 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. Neonatal abstinence syndrome occurred in 69% of the infants exposed to methadone as compared with 52% of those exposed to buprenorphine in the 30 days before delivery (adjusted relative risk, 0.73; 95% CI, 0.71 to 0.75). An inverse association was also observed between buprenorphine exposure (as compared with methadone exposure) and preterm birth regardless of whether exposure occurred in early or late pregnancy in both the unadjusted and adjusted analyses (adjusted relative risk in early pregnancy, 0.58 [95% CI, 0.53 to 0.62]; in late pregnancy, 0.57 [95% CI, 0.53 to 0.62]). Inverse associations were also observed between buprenorphine exposure (as compared with methadone exposure) and small size for gestational age (adjusted relative risk in early pregnancy, 0.72 [95% CI, 0.66 to 0.80]; in late pregnancy, 0.75 [95% CI, 0.69 to 0.82]) and low birth weight (adjusted relative risk in early pregnancy, 0.56 [95% CI, 0.50 to 0.63]; in late pregnancy, 0.56 [95% CI, 0.50 to 0.62]).
A: Delivery by cesarean section occurred in 33.6% of pregnant persons exposed to buprenorphine in early pregnancy and 33.1% of those exposed to methadone (adjusted relative risk, 1.02; 95% CI, 0.97 to 1.08), and severe maternal complications (defined as a composite of potentially life-threatening conditions caused or aggravated by pregnancy) developed in 3.3% and 3.5%, respectively (adjusted relative risk, 0.91; 95% CI, 0.74 to 1.13).