The Elephant in the Room

This is the text from the presentation made to the Interagency Autism Coordinating Committee (IACC) of the US Department of Health and Human Services in October 2010. The presentation is no longer on the committee’s site. As of four years later, we are unaware of new research on the possible link between prenatal ultrasound and autism spectrum diseases.

The Elephant in the Room

What is causing the autism epidemic  – are we looking in all the wrong places?

By Caroline Rodgers       10/22/2010

Presented to the Interagency Autism Coordinating Committee (IACC), US Dept of Health & Human Services

The Birth of an Epidemic

  • The worldwide autism boom identified by the Environmental Protection Agency (EPA) began with children born only 22 years ago in 1988, 1989 and is based on data sets showing autism spikes in the U.S. and countries around the globe
  • Timing of the worldwide autism boom suggests that whatever is causing autism must be the result of a specific change in prenatal exposure in countries around the world that has only increased in the last 22 years

Vaccines Considered

  • A percentage of children develop normally until they regress into autism, which some parents believe was caused by vaccinations
  • Numerous studies throughout the world do not support that vaccines – whether alone, in combination, or with thimerosal cause autism
  • Nonetheless, parental observations are valuable and will someday be explained

Genetics: Elusive Answers

  • Twin studies support the idea that autism is genetic, but researchers have been unable to identify a specific inherited “autism gene”
  • Gene abnormalities associated with autism only apply to a small percentage of people with the disorder – and do not cause autism in all people with the same gene variations
  • The gene pool does not change quickly, so genes alone cannot explain the rapid increase in autism that has occurred

Air Pollution Has Decreased

According to the World Health Organization, particulate air pollution in developed countries has decreased significantly since the 1970s, due to:

  • Phasing out leaded gasoline
  • Equipping cars with catalytic convertors
  • Use of cleaner fuels
  • Reduction of chloroflurocarbons (CFCs) and other ozone‐depleting substances

. . . But while air quality has been improving, the autism rate has only increased – especially in developed countries that now enjoy cleaner air.

Pesticide Usage Does Not Explain Autism Increase

  • Farm pesticide usage in the U.S. hit a low in 1988 – the change-point year for the autism boom
  • According to the Environmental Protection Agency, “pesticide usage can vary considerably from year to year depending on weather, pest outbreaks, crop acreage, and economic forces such as crop prices.”

. . .   But autism rates keep going up.

Chemical Exposure

  • Nearly 85,000 chemicals are registered with the EPA for commercial use – most of which have no developmental toxicity information.
  • Some chemicals have been associated with diminished intelligence or ADHD in children
  • A small number of chemicals such as thalidomide (already unavailable to women who are pregnant or wish to conceive), misoprostol (not used in the United States), the anti-epileptic drug valproic acid and the insecticide chlorpyrifos, have been implicated in causing autism (Source: Dr. Phillip Landrigan, 7/16/2010, IACC Meeting)

Back to Square One

Because no single identified possible risk factor – whether vaccines, genetics, air pollution, pesticides or chemicals – can explain the increase in autism, most researchers believe that autism is caused by a complex interaction of genetics and environmental factors.

2010 IACC Strategic Plan,  “As with many complex disorders, causation is generally thought to involve some forms of genetic risk interacting with some forms of non‐genetic environmental exposure.”

Epigenetics: Genes and Environment

The elegant and emerging science of epigenetics, in which DNA modifications change how RNA is read, seems to be leading the way to discovering autism’s cause.


The EPA autism boom study found that autism increased rapidly at the same time in different countries around the world.

Because every country has different gene pools, air and water quality, building materials, fabrics, diets, environments, chemical exposures and pesticide levels . . .

. . . It would take an impossible series of genetic and environmental coincidences to combine to cause such similar increases in autism at the same time in different cultures and locations around the globe.

Prenatal Ultrasound

  • . . . was in common use in all countries
  • . . . had greatly increased in its exposure to pregnant women over the last 25 years
  • . . . had been the subject of a World Health Organization symposium that determined exposure to it suggested it could cause neurological or behavioral issues in children?
  • . . . in mice, had been proven to cause changes in brain formation consistent with those found   in people with autism?
  • . . . was approved   for use by the Food and Drug Administration (FDA), but that approval was not based on safety considerations?
  • . . . had safety features mandated by the FDA that were ignored   or misunderstood by the majority of practitioners using it?
  • . . . had almost no safety studies published in nearly 20 years – despite rapid changes in technology, gestational window of exposure and number of exposures?

Prenatal Ultrasound is the Elephant in the Room

  • Ultrasound is in common use throughout the world, even in remote, rural regions of developing countries such as China where sex determination is important to expectant parents
  • Ultrasound doubled in use over 10 years, according to trend reports in two countries.
  • Prenatal ultrasound was identified by the World Health Organization in 1982 as having the potential to cause “neurological, behavioral [and] developmental changes” in humans, based on animal studies at Yale University
  • Although all ultrasound intensity limits are approved by the FDA, the Journal of Ultrasound in Medicine notes: “Unfortunately, these limits were not based on safety considerations. Rather, they were based on relative risk for regulatory decisionmaking   purposes . . .”
  • Ultrasound devices have safety indicators required by the FDA, but according to industry surveys, 70% or more of ultrasound practitioners: Could not locate the required safety indicators on their own machines and could not accurately explain how they worked

Dramatic Changes

  • Since the FDA approved an allowable eightfold increase in acoustic output in the early ‘90s, only one prospective study has been undertaken. The study design did not expose fetuses to the first trimester scans that are common today
  • Only one study has investigated the relationship between prenatal ultrasound and autism
  • Meanwhile, grants for prenatal ultrasound safety studies have been repeatedly refused funding, guaranteeing a lack of recent, relevant scientific literature to guide doctors and patients

Most at Risk

Autism surveys and studies have found the following groups of women are at higher risk of bearing children with autism:

  • Mothers who receive first‐trimester care
  • Mothers with higher educations
  • Mothers with private health insurance
  • Older mothers

Only increased exposure to prenatal ultrasound can explain all of the above.

Growing Use

According to a Centers for Disease Control National Vital Statistics Report:

  • In 1989, 48% of mothers who gave birth had at least one prenatal ultrasound
  • By 1997, 64% of mothers had at least one ultrasound
  • This statistical increase in the percentage of pregnant women exposed to ultrasound occurred at about the same time that produced the autism boom

Plea for Research

Considering . . .

  • Existing scientific evidence
  • Lack of safety measures in practice
  • Absence of other leading autism causes

Prenatal ultrasound deserves the kind of attention, funding and research devoted to other possible autism risk factors.

If prenatal ultrasound is causing autism, there is no time to lose.


  • Slide 2: McDonald ME, Paul JF. Timing of Increased Autistic Disorder Cumulative Incidence. Environ Sci Technol. 2010 Mar 15;44(6):2112‐8.
  • Slide 6: Accessed 10‐15‐2010.
  • Slide 7: Accessed 10‐15‐2010.
  • Slide 8: Dr. Philip Landrigan, July 16, 2010 IACC Full Committee Meeting transcript.
  • Siddique J, Lauderdale D, et al. Trends in Prenatal Ultrasound Use in the United States 1995 to 2006. Med Care 2009.Nov;47(11):1129‐35.
  • You JJ, Alter DA, et al. Proliferation of prenatal ultrasonography. CMAJ 2010 Feb 9;182(2):143‐51. Epub 2010 Jan 4
  • Accessed 10‐15‐2010.
  • Slide 17: Ang ES Jr, Gluncic V, et al. Prenatal exposure to ultrasound waves impacts neuronal migration in mice. Proc Natl Acad Scie U S A. 2006 Aug 22;103(34):12903‐10. Epub Aug 10.
  • O’Brien WD Jr, Deng CX, et al. The risk of exposure to diagnostic ultrasound in postnatal subjects: thermal effects. J Ultrasound Med. 2008 Apr;27(4):527‐35.
  • Slide 18: Sheiner E, Abramaowicz JS. Clinical end users worldwide show poor knowledge regarding safety issues of ultrasound during pregnancy. J   Ultrasound Med. 2008 Apr;27(4):499‐501.
  • Slide 19: Newnham JP, Doherty DA, et al. Effects of repeated prenatal ultrasound examinations on childhood outcome up to 8 years of age: follow‐up of a randomised controlled trial. Lancet. 2005 Dec 4 10;364(9450):2038‐44.
  • Grether JK, Li SX, et al. Antenatal ultrasound and risk of autism spectrum disorders. J Autism Dev Disord. 2010 Feb;40(2):238‐45. Epub 2009 Sep 1.
  • Slide 20: Prevalence of Autism Spectrum Disorders – Autism and Development Disabilities Monitoring Network, United States, 2006. MMWR Surveillance Summaries, Dec. 18, 2009/ 58(SS10);1‐20.
  • Accessed 10‐19‐2010.
  • Prevalence of Autism Spectrum Disorders – Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2002. MMWR Surveillance Summaries. Feb. 9, 2007/ 56(SS01); 12‐28. Accessed 10‐19‐2010.
  • Entry into Prenatal Care – United States, 1989‐1997. MMWR Surveillance Summaries, May 12, 2000/49(18);393‐8 10‐19‐2010.
  • Van Meter KC, Christiansen LE, et al. (2010) Geographic Distribution of Autism in California: A Retrospective Birth Cohort Analysis. Autism Research. 2010 3;1‐11.
  • Siddique J, Lauderdale D, et al. Trends in Prenatal Ultrasound Use in the United States 1995 to 2006. Med Care. 2009 Nov;47(11):1129‐35.
  • Maenner MJ, Ameson CL and Durkin MS. Socioeconomic disparity in the prevalence of autism spectrum disorder in Wisconsin. WMJ. 2009 Aug; 108(5):253‐5.
  • Bhasin TK, Schendel D. Sociodemographic risk factors for autism in a US metropolitan area. J Autism Dev Disord. 2007   Apr;37(4):667‐77.
  • Slide 21:   National Vital Statistics Reports, Volume 47, Number 27, Trends in the Attendant, Place and Timing of Births, and in the Use of Obstetric Interventions: United States, 1989‐97 Accessed 10‐19‐2010.
  • McDonald ME, Paul JF.   Timing of Increased Autistic Disorder Cumulative Incidence. Environ Sci Technol. 2010 Mar 15;44(6):2112‐8.