And some scientists say it's fetal ultrasound.

Are Ultrasounds Causing Autism in Unborn Babies?

Is prenatal Ultrasound the main cause of modern autism?

> Then in August 2006, Pasko Rakic, chair of Yale School of Medicine’s Department of Neurobiology, announced the results of a study in which pregnant mice underwent various durations of ultrasound. The brains of the offspring showed damage consistent with that found in the brains of people with autism. The research, funded by the National Institute of Neurological Disorders and Stroke, also implicated ultrasound in neurodevelopmental problems in children, such as dyslexia, epilepsy, mental retardation and schizophrenia, and showed that damage to brain cells increased with longer exposures

Ultrasound and Autism—A Connection?

>Some experts see financial motives behind frequent ultrasounds, which can cost up to several hundred dollars each and can represent significant revenue. http://www.wsj.com/articles/pregnant-women-get-more-ultrasounds-without-clear-medical-need-1437141219

the largest body of evidence on ultrasound safety is surprisingly human studies done in China. Since the studies were performed on women about to undergo elective abortions, the studies have controls (no ultrasound), and various levels of ultrasound exposure, at standard power levels (or lower) for diagnostic imaging ultrasound. The results: Diagnostic ultrasound is found to be extremely damaging to the fetus. Even very low power levels and exposure times cause cell death and cell damage. http://www.amazon.com/review/R2XI27GPH502Q6/ref=cm_cr_dp_cmt?ie=UTF8&ASIN=B00X06QDYS&channel=detail-glance&nodeID=133140011&store=digital-text#wasThisHelpful