TUESDAY, July 9, 2024 — A new study suggests that cannabis use during pregnancy might impact the brain development of a child after birth.
Researchers reported in the journal Nature Mental Health on July 4 that brain imaging of children exposed to cannabis in the womb showed patterns suggesting reduced brain inflammation.
Reduced inflammation in a child’s brain could hinder “pruning,” the natural process where unnecessary neural connections are removed as children grow from early childhood to puberty.
“We see evidence that cannabis exposure may influence the developing brain, consistent with associations with mental health,” said David Baranger, a postdoctoral fellow at Washington University in St. Louis.
A 2020 study in JAMA Psychiatry by the same research team found that prenatal cannabis exposure might increase a child’s risk of mental health, behavior, and brain function problems.
However, the earlier study couldn’t determine if the increased brain risk was solely due to cannabis exposure or if genetics or environment also played a role.
To get a clearer picture, researchers continued analyzing data from the clinical trial that supported their earlier findings. This trial included nearly 12,000 children from across the United States, with brain imaging done at ages 9-10 and 11-12.
Around 370 children were exposed to cannabis before their mothers knew they were pregnant, and 195 were exposed both before and after their mothers learned of the pregnancy.
The researchers found signs of reduced inflammation in the brains of children whose mothers used cannabis, which could have influenced their development.
However, Baranger noted that other factors might also explain the findings.
For instance, cannabis exposure in the womb might lead to accelerated brain aging, or other chemicals inhaled when smoking cannabis could cause these developmental effects.
Baranger hopes that ongoing studies will provide more precise data on the effects of cannabis use during pregnancy.
Meanwhile, women considering using cannabis while pregnant should discuss their options with their doctor, he said in a university news release.
