Pregnancy Weight Gain and Autism Risk
However, this doesn't mean more weight causes neurodevelopmental disorder, authors stress
Small increases in weight -- in 5-pound increments -- while pregnant were linked to a slightly higher but significant risk for autism among the offspring. By contrast, body-mass index (a measurement of body fat based on height and weight) at the start of pregnancy was not associated with a higher risk for autism.
There was an average difference of only about 3 pounds in weight gain when comparing mothers of children with and without autism, the study found.
Bilder reiterated that when it comes to autism risk, weight gain during pregnancy should not be seen as the culprit but rather the canary in the coal mine. She cautioned against any dietary changes based on the findings.
"Good nutrition is essential to a healthy pregnancy," Bilder said. "Clear guidelines are in place that pregnant women can discuss with their medical providers regarding the recommended weight gain for a healthy pregnancy. This study was not designed to impact these guidelines, but rather to provide future direction to researchers as we investigate possible causes that link risk factors with autism."
On that score, Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Cohen Children's Medical Center of New York, in New Hyde Park, said that, unlike previous research, the current investigation shines light on the risk associated with weight gain during pregnancy, rather than before pregnancy.
"The fact that there is a modestly increased risk of autism in pregnancies associated with extra weight gain provides pregnant women with one more reason to be mindful of their weight gain during pregnancy," he said.
"Although it is unclear why there is an increased incidence of autism born to mothers who gained more weight during their pregnancy, hopefully [this study] will provide yet another clue to aid researchers in their quest to better understand what causes autism," Adesman said.