Use of buprenorphine during pregnancy in people with opioid use disorder is safer for the baby than using methadone, a cohort study shows, but adverse maternal outcomes are similar with the 2 agents.
Medicaid data for the United States from 2000 through 2018 were searched to identify pregnant persons who received either of the medications in early pregnancy (through week 19), late pregnancy (week 20 and later), and during the 30 days before delivery. Risk ratios for neonatal and maternal outcomes were calculated. “The data source for the study consisted of 2,548,372 pregnancies that ended in live births,” the authors write. “In early pregnancy, 10,704 pregnant persons were exposed to buprenorphine and 4,387 to methadone. In late pregnancy, 11,272 were exposed to buprenorphine and 5,056 to methadone (9,976 and 4,597, respectively, in the 30 days before delivery). Neonatal abstinence syndrome occurred in 52.0% of the infants who were exposed to buprenorphine in the 30 days before delivery as compared with 69.2% of those exposed to methadone (adjusted relative risk, 0.73; 95% confidence interval [CI], 0.71 to 0.75). Preterm birth occurred in 14.4% of infants exposed to buprenorphine in early pregnancy and in 24.9% of those exposed to methadone (adjusted relative risk, 0.58; 95% CI, 0.53 to 0.62); small size for gestational age in 12.1% and 15.3%, respectively (adjusted relative risk, 0.72; 95% CI, 0.66 to 0.80); and low birth weight in 8.3% and 14.9% (adjusted relative risk, 0.56; 95% CI, 0.50 to 0.63). 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 developed in 3.3% and 3.5%, respectively (adjusted relative risk, 0.91; 95% CI, 0.74 to 1.13). Results of exposure in late pregnancy were consistent with results of exposure in early pregnancy.”
Editorial: “Buprenorphine is now the most commonly used medication in pregnant persons with opioid use disorder,” writes an editorialist. “Although findings from [this study] further reinforce the role of buprenorphine as a first-line treatment option for many pregnant patients, the use of buprenorphine has become more challenging with the escalation of the use of synthetic opioids such as fentanyl. A partial mu-opioid receptor agonist, buprenorphine may insufficiently mitigate opioid cravings and precipitate withdrawal in patients who use fentanyl, which is 50 to 100 times more potent than morphine. Thus, the choice to use methadone or buprenorphine during pregnancy should be the result of a shared decision-making process between a patient and a provider that incorporates factors such as patient preference, previous treatment experiences, and medication availability. Studies such as this highlight the importance of research that evaluates medication use during pregnancy and lactation. Such research is desperately needed to expand treatment options for pregnant persons with opioid use disorder, especially while the opioid crisis continues to unfold.”