#United States #Cincinnati #Opioid Exposure #Brain Development #Newborn Health

The Effects of Prenatal Opioid Exposure on Newborn Brain Development

Recent research sheds new light on the serious implications of opioid use during pregnancy. A study that analyzed data from the Outcomes of Babies with Opioid Exposure (OBOE) project has found that exposure to opioids can significantly affect the developing brains of newborns. The study was published on April 7, 2025, in JAMA Pediatrics and co-authored by Dr. Stephanie Merhar of Cincinnati Children’s Hospital Medical Center.

Understanding the Research Findings

The study examined brain volume in newborns, comparing 173 infants who had been exposed to opioids in utero with 96 babies who were not exposed. Using advanced magnetic resonance imaging (MRI), researchers discovered that the total brain volume of opioid-exposed newborns was nearly 5% smaller than that of their unexposed counterparts. The reduction was evident in key brain areas including the cortical gray matter, deep gray matter, white matter, cerebellum, brainstem, as well as the right and left amygdala.

These findings underscore the varying impact of different opioids and concurrent substance use, with lower volumes more pronounced in infants exposed to multiple drugs. Dr. Merhar emphasized the relevance of this research, stating, “While we’ve known that prenatal opioid exposure can lead to developmental challenges, isolating the effects of opioids from other variables like birth weight and other substance abuse has been complex.”

A Growing Concern: The Scope of Substance Exposure

According to statistics from the Substance Abuse and Mental Health Services Administration (SAMHSA), around 1 in 12 newborns in the U.S. were exposed to substances like alcohol, opioids, and marijuana by 2020, totaling about 300,000 infants. The prevalence of prenatal substance exposure tends to be particularly high in rural regions, surpassing urban averages.

The opioid category includes both illegal drugs, such as heroin and fentanyl, and prescription medications like oxycodone and hydrocodone. Additionally, drugs used to treat opioid use disorder, including buprenorphine and methadone, can contribute to this exposure. The study highlighted how newborns born to mothers using opioids in conjunction with other substances had smaller brain volumes across several regions compared to those exposed solely to opioids.

Clinical Implications and Future Research

Among the opioid-exposed participants, 68.8% were treated with buprenorphine, and 26% were on methadone. The American College of Obstetricians and Gynecologists endorses these medications as viable treatments during pregnancy, acknowledging their necessity for maternal health. However, the findings also call for a deeper investigation into the potential impacts of these medications on fetal development.

Dr. Merhar noted,