Autism 4X more likely if mom is obese with diabetes

"The risk for autism begins in utero," Daniele Fallin says. “It’s important for us to now try to figure out what is it about the combination of obesity and diabetes that is potentially contributing to sub-optimal fetal health." (Credit: iStockphoto)

Children born to obese women with diabetes are more than four times as likely to be diagnosed with autism spectrum disorder as children of healthy weight mothers without diabetes, researchers say.

The findings, published in the journal Pediatrics, highlight what has become a leading theory about autism, that the risk likely develops before a child is even born.

“Our research highlights that the risk for autism begins in utero.”

“We have long known that obesity and diabetes aren’t good for mothers’ own health,” says study leader Xiaobin Wang, professor of child health at Johns Hopkins University’s Bloomberg School of Public Health. “Now we have further evidence that these conditions also impact the long-term neural development of their children.”

Autism spectrum disorder is a neurodevelopmental condition characterized by severe deficits in socialization, by issues in verbal and nonverbal communication, and by repetitive behaviors. Since the 1960s, prevalence rates have skyrocketed, with one in 68 U.S. children now affected, according to the U.S. Centers for Disease Control and Prevention. Obesity and diabetes have also risen to epidemic levels in women of reproductive age over the same time period.

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The researchers analyzed 2,734 mother-child pairs, looking at data on maternal pre-pregnancy weight and whether the mothers had diabetes before getting pregnant or developed gestational diabetes during pregnancy. They followed the children from birth through childhood, identifying 102 diagnosed with autism spectrum disorder over the course of the study.

Children with mothers who were both diabetic and obese were more than four times more at risk for developing than children born to normal weight mothers without diabetes, they found.

“Our research highlights that the risk for autism begins in utero,” says co-author M. Daniele Fallin, director of Johns Hopkins’ Wendy Klag Center for Autism and Developmental Disabilities. “It’s important for us to now try to figure out what is it about the combination of obesity and diabetes that is potentially contributing to sub-optimal fetal health.”

Previous studies had suggested a link between maternal diabetes and autism, but this is believed to be the first to look at obesity and diabetes in tandem as potential risk factors.

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Why obesity and diabetes might contribute to autism risk isn’t well understood. Obesity and diabetes in general cause stress on the human body, the researchers say. Previous research suggests maternal obesity may be associated with inflammation in the developing fetal brain. Other studies suggest obese women have less folate, a B-vitamin vital for human development and health.

Women thinking about having children need to think about their obesity and diabetes status not only for their own health, but also because of the implications for their children, the researchers say. Better diabetes and weight management could have lifelong impacts on mother and child, they say.

“In order to prevent autism, we may need to consider not only pregnancy, but also pre-pregnancy health,” Fallin says.

The parent study, the Boston Birth Cohort, was supported in part by the March of Dimes, the National Institute of Environmental Health Sciences and the National Institute of Child Health and Human Development. The Pediatrics study was supported in part by the Ludwig Family Foundation, the National Institute of Allergy and Infectious Diseases and the Maternal and Child Health Bureau.

Source: Johns Hopkins University