Can Stress During Pregnancy Lead to Autism?

You might want to take a few deep breaths before you read this. 

Pregnancy Stress Linked To Autism Piotr Marcinski/Shuterstock

Seems like almost every day researchers are pointing the finger at something as a possible cause of autism spectrum disorder (ASD)—vaccines, diet, excess folic acid...even circumcision! Now the latest in a long line of culprits is apparently stress during pregnancy.

Wait, what?

We already know maternal stress has been linked to a whole bunch of unwelcome outcomes like pre-term delivery and low birth weight, not to mention an increase in behavioral problems in kids later on. But now there's a new study in the New England Journal of Medicine that's telling us that being stressed out while pregnant may cause autism, too.

"We know that some mothers who experience significant levels of stress don't have children with autism, but others do," explained senior author of the study, David Beversdorf, M.D. "Autism was thought to be largely a genetic disorder, but previous research has shown that environmental influences such as stress can play an important role in the development of the condition."

It's a good thing expectant mamas have nothing to freak out over, then—you know, besides genetic testing, the fear of developing gestational diabetes, or preeclampsia, or basically failing epically as a parent once the baby arrives.

To gather intel, the researchers asked moms of kids with autism about possible stresses they may have experienced during pregnancy—things like the loss of a job, moving or getting divorced. The mothers' blood was then tested for a variation of a stress-sensitive gene that regulates serotonin—when a variation of the gene is present, the amount of serotonin is altered, causing an increased reaction to stress.

Their findings? The moms of kids with ASD who had the variation, reported feeling more stress during the end of the second and the beginning of the third trimester of pregnancy.

Yikes! Keep in mind, however, that we are talking about pretty big stresses here (as opposed to worrying about things like, say, pregnancy weight gain). Plus, this was only an observational study, and Beversdorf says future confirmation of the results is necessary. "More research is needed to understand the mechanisms of how this gene-stress interaction works," he explained. "But hopefully this could someday help prevent some cases of autism."

In the meantime, try not to sweat the findings too much, OK?