Children born to mothers who used buprenorphine for opioid addiction during pregnancy do not have a higher risk of neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD) and autism, compared with children whose mothers took methadone, according to a large US study published by The BMJ on Apr. 17.
The findings are significant because they provide more evidence about the long-term safety of medications used to treat opioid use disorder in pregnant women. Previous research has shown that buprenorphine is linked to fewer serious health problems in newborns than methadone, but less was known about the effects as children grow older.
Researchers analyzed Medicaid health insurance data from over 2.5 million live births between 2000 and 2018. They compared the risk of neurodevelopmental disorders in more than 12,600 children exposed prenatally to buprenorphine with over 5,300 children exposed to methadone before birth. The children were monitored up to age eight for conditions including autism, ADHD, speech or language disorders, behavioral disorders, and intellectual disability.
After accounting for factors such as maternal age, ethnicity, tobacco and alcohol use, chronic pain conditions, mental health issues, and other medication use or healthcare needs during pregnancy, the researchers found that prenatal exposure to buprenorphine was associated with a slightly lower (19%) risk of any neurodevelopmental disorder by age eight compared with methadone exposure. There were also lower risks observed for specific conditions: an 11% reduction in ADHD risk; a 16% reduction in speech or language disorder; and a 26% reduction in autism.
Among women already using either medication before pregnancy (prevalent users), those whose children were exposed prenatally to buprenorphine had a further reduced (38%) risk of any neurodevelopmental disorder compared with those exposed to methadone. This difference was not seen among women who started treatment during pregnancy (new users), which researchers say requires further investigation.
While this observational study cannot establish cause and effect definitively—and some limitations remain—the authors conclude: "The findings of this study suggest no increased risk of long term adverse neurodevelopmental outcomes among children with prenatal exposure to buprenorphine versus methadone." An editorial accompanying the study notes these results should increase confidence in using buprenorphine during pregnancy but also highlights that methadone remains important for individuals with higher opioid tolerance or complex needs. Both articles emphasize ongoing challenges such as stigma and access barriers faced by people seeking care for opioid use disorder.
