Autism linked to maternal obesity: Study

By Dr. Ananya Mandal, MDApr 10 2012

A new study shows that rising obesity among pregnant women may be contributing to the rising number of children diagnosed with autism.

The study published Monday in the journal Pediatrics shows that compared to non-obese mothers those who were obese before pregnancy had a 1.6 times increase in the likelihood of having a child with autism.

The study, conducted by a group of researchers at UC Davis, involved a thousand children between the ages of two and five. The study included more than 500 autistic children in California and compared them to the same number of children who did not have autism. Mothers were asked about their health and medical records confirmed the conditions of half of the women. It found mothers who are overweight during pregnancy are 60 percent more likely to have an autistic child.

The U.S. Centers for Disease Control and Prevention (CDC) in Atlanta estimates that one in 88 American children has autism - that's up from 1 in 110 children in 2006. That risk goes up to a 1 in 53 chance when the mother is overweight. The reason is unclear, but researchers believe excess blood sugar and inflammation-related substances in the mothers blood maybe to blame.

Jodie Howard is the parent of a seven year old autistic son and the chairman of an autism parents group in Fresno. She called the numbers scary but believes more research needs to be done to make a clear connection between the two. “There are so many factors involved that I don't see how we can link it to just one thing,” Howard said.

ABC News Medical Editor Dr. Richard Besser and other doctors believe that these numbers are reason for concern with one-third of women of child bearing age overweight in the United States. “We need to understand what really causes autism. What are the genetic factors? What are the environmental factors? How can you identify those risk factors? And are any of them preventable?” Besser told Action News.

Both doctors and parents agree more studies need to be done to confirm the results. “Until we have a clear diagnostic test, it's going to be a little murky, but it's so important for parents to look for signs are they're children developing normally,” Besser said. “I'm glad we're looking in various places because we don't know what causes autism and if we did we could do so much more for our children and adults that have autism,” Howard said.

Dr. Tom Frazier of Cleveland Clinic emphasizes that mothers who really want to be healthy, and want that for their children, need to pay attention to their own health. More than a billion dollars have been spent on autism research in the last 10 years, but in many cases, they've been “association” studies, which don't prove direct cause and effect. This year there have been studies linking some genetic traits with autism.