Here is just a partial list of correlates, risk factors, and possible causes that have been the subject of serious studies:
• Air pollution and proximity to freeways;
• Maternal thyroid issues;
• Autoimmune disorders;
• Induced labor;
• Preterm birth;
• Birth by cesarean section;
• Maternal and paternal obesity;
• Maternal and paternal age;
• Maternal post-traumatic stress disorder;
• Smoking during pregnancy;
• Antidepressant use during pregnancy.
For children with autism and a class of genetic disorders, exposure to diagnostic ultrasound in the first trimester of pregnancy is linked to increased autism severity, according to a study by researchers at UW Medicine, UW Bothell and Seattle Children's Research Institute.
The study published Sept. 1 in Autism Research studied the variability of symptoms among kids with autism, not what causes autism. What they found is that exposure to diagnostic ultrasound in the first trimester is linked to increased autism symptom severity. The greatest link is among kids with certain genetic variations associated with autism; 7 percent of the children in the study had those variations.
FDA guidelines currently recommend that diagnostic ultrasound only be used for medical necessity.
"I believe the implications of our results are to bolster the FDA guidelines," said corresponding author Pierre Mourad, a UW professor of neurological surgery in Seattle and of engineering & mathematics in Bothell who specializes in translational research on ultrasound and the brain.