How an illness during pregnancy may lead to autism: new study

Contracting a viral infection during pregnancy could lead to an autism diagnosis for the child, new research on mice finds.

Irene Sanchez Martin, a postdoctoral researcher at Cold Spring Harbor Laboratory on Long Island, said mouse embryos may show signs of developmental deficits soon after their mother is exposed to a virus.

“The model we use is very well established for autism spectrum disorder,” Sanchez Martin explained. “The difference in my work is that I check what happened to the fetuses 24 hours after exposure to maternal inflammation, rather than analyzing the behaviors of the offspring as adults.”

Autism — which is estimated to affect one in 36 US children — is a developmental disorder that affects how people learn, behave, communicate and interact with others. There is no single known cause of autism, but it’s believed that genetics and environmental factors play a role.

Scientists have long been studying maternal immune activation, the notion that inflammation due to infection during pregnancy can affect a fetus’ developing brain, increasing the risk of autism.

Cold Spring Harbor Lab says Sanchez Martin’s work represents the first look at the effects of prenatal inflammation on an embryo in an autism model.

Sanchez Martin reports that in her experiments, all the female mice embryos seemed protected from developmental deficits while up to one-third of the male embryos were strongly affected.

Boys are nearly four times more likely to be diagnosed with autism than girls, according to the Centers for Disease Control and Prevention (CDC).

Sanchez Martin’s research was presented this week at the Society for Neuroscience conference in Chicago. She hopes her work will eventually help identify early autism warning signs — even before birth.

Her study comes after researchers from the University of Michigan and CDC reported that children born with congenital cytomegalovirus, a common viral infection, are nearly 2.5 times more likely to be diagnosed with autism.

The theory is that the virus can trigger maternal immune activation. Researchers are advocating for routine neonatal screening for cytomegalovirus, which is often symptomless in pregnancy and at birth.