When a pregnant woman develops diabetes during the first 26 weeks of gestation, her baby has an increased risk of developing autism spectrum disorder, according to a new study published in The Journal of the American Medical Association.
No one knows what causes autism spectrum disorder, but researchers are learning more about it. Autism spectrum disorder, or ASD, is a developmental disorder where the brain does not function normally. ASD doesn't go away, and those who have it have difficulty communicating, interacting socially with others and controlling their behavior.
Parents like Megan Dahlberg can notice something is wrong even before their child is diagnosed with ASD. Her son, Levi, was diagnosed with ASD when he was two. “Levi was saying 'hi' and 'bye,' 'kitty' and 'tree,' and right about the same time he started walking he just stopped," Dahlberg said. "Any sort of communication just went away around 16 months.”
Dr. Edward Curry is one of the co-authors of a new study on autism spectrum disorder conducted by Kaiser Permanente Southern California. He said, "Early in pregnancy that first and second trimester is where the fetal brain is developing. That’s a period of time where the brain is most susceptible to insults, so having an elevated blood sugar is an insult to that fetus.”
Anny Xiang was the lead author. She and other researchers reviewed the medical records of more than 300,000 thousand children born between 1995-2009 at Kaiser Permanente Southern California hospitals. They noticed something about children born to women with gestational diabetes. “Exposure to gestational diabetes diagnosed before 26 weeks gestation was associated with increased risk of autism spectrum disorder in the offspring,” Xiang said.
Oddly enough, children born to women diagnosed with pregnancy-related diabetes after 26 weeks had no increased risk of having autism, nor did children whose mothers had diabetes before becoming pregnant. Dr. Curry said the study shows how critical early prenatal care is.
"You want the mothers to come in not only to check for diabetes but also to be on their prenatal vitamins, those things that can have a positive impact on the developing fetus,” he said.
The causes of autism spectrum disorder are unknown, but researchers are finding factors that increase the risk. Being born too early, too small, being born to older parents, having a sibling with autism, being exposed to certain drugs or heavy metals during pregnancy - all are risk factors according to the U.S. Centers for Disease Control and Prevention. The World Health Organization estimates that one child in 160 has an autism spectrum disorder.
There's no cure for ASD, but therapy can help and research is ongoing. ASD is heavily influenced by genetic factors so researchers are looking for genes associated with the disorder. Others are studying the differences in brain anatomy and functioning in people with ASD. Every parent of a child with the disorder hopes there will be a cure one day. Dahlberg said, "You just want them to be able to thrive both socially and intellectually, and that’s my hope.”
The study was published in The Journal of the American Medical Association.