Report: Autism starts in the womb

Researchers this week published a new report that indicates autism starts in the womb.

Researchers examined brain tissue from children who died and had autism. The tissue revealed patches of disorganization in the cortex, the thin sheet of cells that’s important for learning and memory, according to an NPR article.

Tissue samples from children without autism didn’t have those characteristics, according to the report, which was published in New England Journal of Medicine.

Organization of the cortex begins during the second trimester of pregnancy, according to the article.

“So something must have gone wrong at or before that time,” Eric Courchesne, an author of the paper, told NPR.

In typical kids, the cortex is “like a layer cake,” Courchesne said. “There are six layers, one on top of the other, and in each layer there are different types of brain cells.”

He suspected the layers might be altered in the brains of autistic kids. He and a team of researchers studied cortex samples from 11 children with autism and 11 children without, according to the article.

In the children without autism, the cortex had six distinct layers. But in children with autism, there were patches in which cells in certain layers appear to be missing. Instead of distinct layers, there are disorganized collections or brain cells, according to the NPR article.

The new report adds to the evidence that autism starts in the womb, Dr. Stanley Nelson, a geneticist at UCLA, told NPR.

“The overwhelming set of data is that the problems are existing during brain development, probably as an embryo or fetus,” he said.

Marissa Harshman

Marissa Harshman

I'm the health reporter for The Columbian newspaper in Vancouver, Wash. I started at The Columbian -- my hometown newspaper -- in September 2009. Reach me at or 360-735-4546.

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