Children whose mothers developed gestational diabetes before they were 26 weeks pregnant were almost 42 times more likely to be diagnosed as autistic.
US researchers followed 322,000 children born at hospitals in southern California between 1995 and 2009. They found a 63% increased chance of the child being diagnosed with autism if their mom had developed diabetes early in their pregnancy. When other factors that influenced autism, such as a mother’s age, were taken into account the risk was found to be 42%.
The report’s author, Anny Xiang, of the Kaiser Permanente Southern California Department of Research and Evaluation, emphasised that “the findings reveal associations between gestational diabetes and risk of a child developing autism rather than proving a cause and effect relationship”.
She said future studies should try to find out whether early treatment of gestational diabetes could reduce the risk of autism.
A South African doctor who treats autistic children, Dr Louise Lindenberg, said: “The general consensus is that autism is caused by a combination of factors: there seems to be a genetic predisposition, which is brought to expression by environmental insults.”