Among those are untreated phenylketonuria, rubella, celiac disease, and chemical exposure during pregnancy.
Autism occurs by itself or in conjunction with other disorders that affect brain function.
No know factor in the psychological environment of a child has been shown to cause autism. Autism has been found among children of all racial, ethnic and socioeconomic backgrounds. In all, speculation leans strongly toward a biogenic explanation and autism is no longer seen as a psychogenic problem. Autism is considered a lifelong disorder.