The study is part of an ongoing effort to find preventable factors that may increase the risk of autism. Researchers compared the medical histories of 1,000 children in California to take a closer look at the impact of obesity, diabetes, and high blood pressure on pregnancy. They found that while women with diabetes were only slightly more likely to have a baby with autism, they were twice as likely to have a child with a different neurodevelopmental disorder.
The reason for these findings remains uncertain, though it is possible that high levels of blood glucose in obese and diabetic women may have a negative impact on a fetus’ developing brain. Higher levels of glucose can cause a baby to grow faster and require more oxygen as a result—if insufficient oxygen is provided, problems with brain development can arise. The inflammatory proteins produced by fat cells are another possible cause, since they are involved in normal brain development. Too many or too few of these proteins might have an adverse effect on how the brain develops. Either way, researchers remain unsure of the impact of diabetes or obesity on fetal growth.
While researchers note that more research is needed to confirm the connection between maternal obesity and autism, they point out that U.S. autism rates have increased along with obesity. Until more information is known, the study’s lead author Paula Krakowiak suggests that obese moms take these new findings as another reason to lose weight. A woman is considered obese when she's about 35 or more pounds overweight or has a body-mass index (BMI) of 30 or higher.
“It doesn’t hurt anybody to lose weight and it comes with other benefits to the mom. So losing weight not only will help you, but it also might potentially help your child to be healthier,” Krakowiak says.