Uses & Benefits of Ayurvedic

Because if this, there have been several news stories about autism. The Wall Street Journal had this article on rates being peculiarly high in specific areas of California:

“An area including West Hollywood, Beverly Hills and some less posh neighborhoods that accounted for 3% of the state's new cases of autism every year from 1993 to 2001, even though it had only 1% of the population."

Why are cases of autism rising, especially in industrialized countries and in what seems to be in higher socioeconomic classes? The prevalence of autism is now reported to be ~1/150 American children (maybe even higher). Scientists still don’t know what causes autism other than some combination of genetics and environment.

What environmental factors might be present in these neighborhoods with high autism rates? Is it the simple reason that they have better medical care and thus more doctors giving the diagnosis? Or is there something in the environment that could be causing this?

There have been questions on whether prenatal ultrasounds could play any role, so I've been searching for studies... and it's frustrating me that I can't come up with a good answer.

Ultrasound examinations are often given multiple times during pregnancy and provide valuable information. With that in mind, this letter and this review article (full text here), make convincing arguments for why this is an area in need of further study.

• Studies on people with autism show irregularities in several regions of the brain, suggesting that autism could be a result of disrupted normal brain development in fetal life.
• The use of prenatal ultrasounds has grown along with the rise in autism cases.
• Ultrasonography is used to evaluate fetal maturity, to determine delivery date, and to assess fetal growth, multiple births, and high-risk pregnancies. Pregnant women, with access to prenatal care, often have multiple ultrasound exams during pregnancy.
• Ultrasound is used in physical therapy to deliver deep heat to tissues.
• Liquid (including amniotic fluid) absorbs more heat energy than solid tissue.
• The fetal brain is sensitive to many things (drugs and alcohol, for example).
• In 2004, the FDA published this warning against ultrasound “keepsake” images, saying:

“Ultrasound is a form of energy, and even at low levels, laboratory studies have shown it can produce physical effect in tissue, such as jarring vibrations and a rise in temperature.”

While maintaining my skepticism, these points do make me wonder... could ultrasound-generated heat put a fetus at risk?

Until this paper came out this past month, there have been no studies looking at this question. Comparing 362 children having an autism spectrum disorder to 393 controls, they did not find an association between risk of an autism and ultrasound exposure.

In order to avoid an ungrounded public fear of ultrasound (similar to the >10 year and ultimately false vaccine hypothesis which ended up putting people's health at risk) we need more studies to answer this question. If we could identify large sources of data of incidence of autism and use of ultrasound during their mothers’ pregnancy, it would seem to be a relatively straightforward analysis.