Study finds possible risk of birth defects with first trimester use of methadone versus buprenorphine

Both buprenorphine and methadone treat OUD, but there is limited understanding of how in-utero exposure affects infants. Researchers of a new study published in JAMA Internal Medicine used Medicaid data to gauge the risk of congenital malformations in neonates whose mothers received buprenorphine or methadone while carrying them.

After examining Medicaid data from more than 13,000 pregnancies during 2000 to 2018, outcomes data showed that birth defects were more prevalent overall with first trimester exposure to methadone than with similar exposure to buprenorphine. In 9,514 cases, pregnant parents received buprenorphine during the first 90 days of gestation. In 3,846 cases, they received methadone.

The relative risk reduction with buprenorphine was 18%, the equivalent of 1 fewer event per 100 patients compared with methadone. Similar patterns emerged when investigators looked specifically at birth defects linked with opioid use, the only exception being GI malformations, which were more likely with fetal exposure to buprenorphine.

They noted that risk of birth defects is just one factor to consider when choosing an intervention for OUD in pregnant women. Access to treatment, previous treatment success, and the odds of retention in treatment should also inform the decision, they added.