Antenatal Opioid Exposure and Global and Regional Brain Volumes in Newborns

Yao Wu1, Stephanie L Merhar2,3, Carla M Bann4

  • 1Developing Brain Institute, Children's National Hospital, Washington, DC.

JAMA Pediatrics
|April 7, 2025
PubMed

Insights

Antenatal opioid exposure in newborns is linked to smaller brain volumes, including total brain, cortical, and amygdala regions. These findings highlight the developing brain's vulnerability to prenatal opioid exposure.

Area of Science:

  • Neuroscience
  • Developmental Biology
  • Public Health

Background:

  • Antenatal opioid exposure is associated with impaired brain growth.
  • Previous studies had limitations in sample size and control groups, leaving impacts poorly understood.

Purpose of the Study:

  • To compare global, regional, and tissue-specific brain volumes in opioid-exposed newborns versus unexposed controls.

Main Methods:

  • The Outcomes of Babies with Opioid Exposure (OBOE) study recruited newborns from 4 US sites.
  • 3D volumetric MRI was used to assess brain volumes in opioid-exposed and unexposed newborns before 8 weeks of age.
  • Analysis of covariance compared brain volumes, adjusting for key covariates.

Main Results:

  • Opioid-exposed newborns had significantly smaller total brain volume (19.55 cm³ less) and reductions in cortical, deep gray matter, white matter, cerebellar, brainstem, and amygdala volumes compared to controls.
  • Methadone-exposed newborns showed smaller white matter volume, while buprenorphine-exposed newborns had smaller right amygdala volume.
  • Newborns exposed to opioids alone or with other substances showed significant reductions across multiple brain regions.

Conclusions:

  • Significant reductions in global and regional brain volumes were observed in antenatally opioid-exposed newborns compared to controls.
  • These findings suggest the developing brain is vulnerable to antenatal opioid exposure.
  • The effects vary depending on the type and number of substances exposed to during pregnancy.
Abstract

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