JUN 14, 2016

Stress Plus Pregnancy: Could Autism be the Result?

WRITTEN BY: Brenda Kelley Kim

Any woman who has been pregnant can attest to the stress it can cause. Even in in a typical pregnancy, especially with first time mothers, stress can be a concern. If depression or anxiety was a problem before the pregnancy, it’s likely that will continue. The complication then becomes whether or not to continue taking anti depressants or other medications during pregnancy. Some studies have shown that these medications can increase the risk of autism, so there again, more stress for the expectant mom.

New research from the University of Missouri School of Medicine suggests that stress itself, regardless of medication, during pregnancy can lead to instances of autism. Researchers there observed a variant of a stress-sensitive gene and studied exposure to stress during pregnancy among two groups of mothers of children with autism. The researchers believe the results of this research could help figure out which women were at a greater risk for having a child on the autism spectrum based on their exposure to stress during specific times in their pregnancies.

David Beversdorf, MD, associate professor in the departments of radiology, neurology and psychological sciences at the University of Missouri and the MU Thompson Center for Autism and Neurodevelopmental Disorders, and senior author of the study said in a press release, "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. We know that some mothers who experience significant levels of stress don't have children with autism, but others do. To help understand why, we studied a gene that is known to affect stress and found a link between it and the development of autism with exposure to stress."

Graduate student, Patrick Hecht, PhD., in collaboration with Xudong Liu, PhD., at Queen's University in Ontario, Canada, the researchers studied two separate groups of mothers of children with autism spectrum disorder. One group in Missouri and another located near Queen’s University. The mothers were surveyed about stress during their pregnancy, such as the loss of a job, moving or divorce. Blood tests were conducted to look for a variation of the stress-sensitive gene known as 5-HTTLPR, which regulates the neurotransmitter serotonin in the nervous system. When a variation of this gene is present, levels of serotonin are are lower and this can cause an increased reaction to stress.

In both groups, mothers of children on the autism spectrum who had the stress sensitive gene reported experiencing more stress during the end of the second and the beginning of the third trimester of pregnancy, compared to mothers who did not carry the altered gene. Dr. Beversdorf was quick to point out that the study was observational and that more research is needed before women cn be reliably identified as being at risk for bearing a child who might have autism as a result of stress exposure.
The study, "Maternal Serotonin Transporter Genotype Affects Risk for ASD with Exposure to Prenatal Stress," recently was published by Autism Research, the journal of the International Society for Autism Research. The video below explains more about the research and what it could mean going forward in autism and genetic studies.

Sources: University of Missouri, JAMA Pediatrics, Autism Research