More circumstantial evidence

Obesity in pregnancy linked to autism

While the study did not say whether the mother's weight or diabetic status caused the children's developmental problems, it did find strong associations between the likelihood of such ailments and the mother's health in pregnancy.
For instance, mothers who were obese were about 67 percent more likely to have a child with autism and more than twice as likely to have a child with some kind of disorder than normal-weight moms without diabetes. More than 20 percent of the mothers of children with autism or other developmental disability were obese. Just 14 percent of the mothers of normally developing children were obese at the time of pregnancy, it said.
Also, the autistic children of diabetic moms appeared to have more severe disabilities -- with greater deficits in language and communication skills -- than the autistic children of normal-weight moms.