Here’s one more reason why mothers should stay proactive about their prenatal health. Developing diabetes while pregnant—a condition known as gestational diabetes—may increase women’s chances of having a child with autism, according to findings published in the Journal of the American Medical Association, reports Time.com.

Gestational diabetes occurs in moms-to-be who have never been diabetic but who have high blood sugar levels during pregnancy. The illness occurs when the body is unable to make and use all the insulin it needs for both mother and child, and affects between 9 and 14 percent of pregnancies in the United States.

For the Kaiser Permanente-funded study, researchers looked at the medical records of 322,000 children born at Kaiser Permanente hospitals between 1995 and 2010. Among this group of infants, 3,400 children were diagnosed with autism spectrum disorder (ASD). Of these kids, 130 had been exposed to diabetes during their mother’s pregnancy.

Scientists found that children whose mothers developed gestational diabetes by their 26th week of pregnancy were 40 percent more likely to be diagnosed with autism than those with healthy moms.

The study suggested that babies’ exposure to high levels of blood sugar from their mothers during the time of early development could actually disrupt fetal brain growth, especially in regions important for communication and social interaction.

Interestingly, children whose mothers had diabetes prior to getting pregnant, or who developed diabetes after the 26th week of gestation, faced no extra autism risk.

For more information about autism spectrum disorders, click here.