Do Sonograms Cause Autism? A New Study

A new paper (“Are Prenatal Ultrasound Scans Associated with the Autism Phenotype? Follow-up of a Randomised Controlled Trial” by Yonit K. Stoch, Cori J. Williams, Joanna Granich, Anna M. Hunt, Lou I. Landau, John P. Newnham and Andrew J. O. Whitehouse) takes another look at the results of a randomized trial started in 1989. Half the mothers were given one ultrasound during their pregnancy, the rest got five. This study gave a questionnaire sensitive to autism-like traits to the now-grown-up children. This is potentially more sensitive than binary (yes/no) assessment because the questionnaire has about 50 questions.

Here is the entire abstract:

An existing randomised controlled trial was used to investigate whether multiple ultrasound scans may be associated with the autism phenotype. From 2,834 single pregnancies, 1,415 were selected at random to receive ultrasound imaging and continuous wave Doppler flow studies at five points throughout pregnancy (Intensive) and 1,419 to receive a single imaging scan at 18 weeks (Regular), with further scans only as indicated on clinical grounds. There was no significant difference in the rate of Autism Spectrum Disorder between the Regular (9/1,125, 0.8 %) and Intensive (7/1,167, 0.6 %) groups, nor a difference between groups in the level of autistic-like traits in early adulthood. There is no clear link between the frequency and timing of prenatal ultrasound scans and the autism phenotype.

Parrish Hirasaki pointed out to me that when the study was done the intensity of ultrasounds was eight-fold less than now. Here’s what the paper says about this:

Technological advancements over the past two decades have led to considerable improvements in ultrasonographic capabilities, with corresponding increases in acoustic output.

Did you read that and realize the intensities have increased by a factor of eight? Neither did I. Such a big difference in intensity means the results are not serious evidence — contrary to what the abstract implies — against the idea that sonograms are now causing autism.

More Asked about the failure to make clear the difference in intensity, the corresponding author, Andrew Whitehouse, replied:

The parameters of the ultrasound scans were reported clearly in the Methods section, and we refer to several other articles that include a description of the USS administered in this cohort. We are also very clear in the Discussion when we state that “the current study was not designed to investigate the use of [modern] instruments”.

I disagree. So what if the parameters of the ultrasound scans were reported clearly in the Methods section? That’s not the issue. The issue is failure to make clear the huge intensity difference between the ultrasounds they studied and modern ultrasounds. Saying that “the current study was not designed to investigate the use of [modern] instruments” does not make clear at all (much less “very clear”) how much modern ultrasounds differ from the ultrasounds actually studied. Any study can put caveats like that at the end. Yet few studies are as irrelevant as this one to the question they claim (in the title, abstract and introduction) to help answer.

7 Replies to “Do Sonograms Cause Autism? A New Study”

  1. Seth, the manner in which “Dr.” Whitehouse responded to your inquiry seems very suspicious to me, suggesting a dishonest answer.

    Maybe I’m being overly cynical, but his comments to you make me suspect serious conflicts of interest on the part of the investigators; probably difficult to prove of course. Makes me wonder, however, if the journal that published this, or any of the listed investigators, receive $$ from the major manufacturers of ultrasound devices such as GE, Siemans and SonoSite.

    BTW, I note his basic background is as a speech pathologist who later acquired a PhD in psychology, according to his profile on the website of his employer, the Telethon Institute for Child Health Research based in Perth, Australia. Makes me wonder if any of the investigators were MDs.

    Seth: My guess is that the article is so misleading because to make clear its shortcomings — its lack of relevance — would have made it harder to publish. But that’s just a guess.

  2. The study is misleading but not useless. It is evidence that old intensity ultrasounds don’t cause autism.

    It leads to the inevitable question: did the recent surge in autism diagnoses began when old intensity ultrasounds were done or did it wait until modern eight-times intensity? If the former, there is evidence that ultrasounds are not responsible. If the latter, there is evidence that they are.

  3. It seems that it would be very easy to test this in mice.

    At least whether prenatal ultrasound radiation affected socialization or ability to learn.

    Seth: It has been tested in mice. Realistic durations and intensities of ultrasound changed (i.e., damaged) the brains of fetuses.

  4. Seth,

    are you aware that there is also a very strong correlation between Pitocin (oxytocin) administration and autism? I think that both make strong case, though no studies have been conducted yet.

  5. Have you read _The Brain that Changes Itself_? IIRC, that’s where I ran into the theory that exposure to white (unstructured) noise before age two could lead to autism because the brain is trying to make sense of sounds where there is no sense.

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