Caroline Rodgers: Autism, Prenatal Ultrasound, and Electronic Fetal Monitoring

Caroline Rodgers

You seem to be very passionate about your work regarding autism’s etiology. How did you first become interested in the subject?

First, I want to say what an honor it is to be invited to present some of my ideas on this blog. Dr. Casanova and his wife, Emily, have produced a considerable body of work investigating the possible role that ultrasound may play in causing autism and have shared their research at important international forums, even in the face of opposition. I have corresponded with Dr. Casanova for over a decade and found him unfailingly helpful in reviewing my manuscripts, usually on an informal basis, and responding to any queries I have sent his way. He combines deep knowledge with a compassion for the challenges faced by individuals with autism and the people who love them.


I initially became interested in autism back in the ‘60s when I volunteered at a day camp for children with disabilities, one of whom was profoundly autistic with symptoms such as averted gaze, non-verbal outbursts and stimming. At the time, autism prevalence was so low that most family doctors did not see a single case, so autism has been on my personal radar for a long time. Decades later when it became apparent that autism was becoming less rare, the Centers for Disease Control responded by forming the Autism and Developmental Disabilities Monitoring Network (ADDM), which began collecting data in 2000. I wondered, along with many others: Why now? Early suspicion fell on childhood vaccines, most likely due to the sizable percentage of autistic children who had begun developing normally only to regress into autism, which some parents attributed to their child’s last vaccine. Although any such link has been disproved repeatedly, vaccine mistrust has taken root in society to the point of presenting new public health threats related to the current pandemic.

In 2005, despite initial personal skepticism, I found there was credible evidence that prenatal ultrasound could be implicated in causing autism and started working on my article, “Questions About Prenatal Ultrasound and the Alarming Increase in Autism” for Midwifery Today. The next year when it was still in manuscript form, a study by Yale neuroscientist Pasko Rakic found that some mice exposed to 30 minutes of ultrasound during a particular gestational window had disruptions in neuronal migration, spurring interest in a possible link to autism. I cited this study when my article was published in 2006 – although the difficulty in applying this effect to humans was that 30 minutes in a rodent life is equal to many hours in a human life, far longer than a single diagnostic ultrasound session. Nonetheless, Rakic’s research led to a few investigations into whether there was a correlation between prenatal ultrasound exposure of various types during different trimesters and autism outcomes. When no significant results were published, funding dried up and this research direction was largely abandoned.

I then expanded my research into other areas of public health, developing two peer-reviewed variations of a hypothesis – one in 2011 and the other in 2020 – regarding what is causing the increase in Alzheimer’s and other neurodegenerative diseases. I also wrote articles on maternal and neonatal health, including two peer-reviewed commentaries for the Journal of Midwifery and Women’s Health. Although these subjects would seem to be departures from my work on autism, the background information I gained regarding neuroscience and obstetrics each contributed to the article under discussion today. Outside of writing for publication, I made presentations as a member of the public at various federal forums, such as the Interagency Autism Coordination Committee (IACC) and Council of Alzheimer’s Research, Care and Services. One presentation I made at the IACC in 2010, titled “The Elephant in the Room,” caught the attention of retired NASA mechanical engineer Parrish Hirasaki, who created the website as a resource for individuals interested in reviewing the evidence.

How did you develop the ideas presented in your most recent paper, “Continuous Electronic Fetal Monitoring During Prolonged Labor May Be a Risk Factor for Having a Child Diagnosed with Autism Spectrum Disorder”? (Continuous electronic fetal monitoring during prolonged labor may be a risk factor for having a child diagnosed with autism spectrum disorder – ScienceDirect)

The idea that electronic fetal monitoring (EFM) in combination with prolonged labor could be an autism risk factor was a byproduct of a completely different research direction. I was starting to research a paper addressing genetic mutations called copy number variations (CNVs) because there was an increasing amount of scientific literature noting that some CNVs associated with autism were also associated with Attention-Deficit/Hyperactivity Disorder (ADHD). I was finding that there also was crossover among CNVs associated with pediatric food allergies and autism, and I suspected that these and possibly other health issues that have become more common might have a shared etiology. Some of these CNVs were not inherited, so the question I wanted to answer was: What could have caused these non-inherited mutations? Although prenatal diagnostic ultrasound had not been found to be implicated in causing autism, another form of ultrasound, EFM, which typically is employed continuously throughout labor, had only been studied regarding a possible outcome of cerebral palsy (where no correlation was found), not autism or other developmental disorders.

My “Ah-ha!” moment came when I re-read two papers as part of my background research. To try to get a handle on the history of EFM, I re-read “Changes in Labor Patterns over 50 Years” by Laughon, et al. This study made headlines when it was published in 2012 because it discovered that there had been a considerable increase in the duration of labor over five decades. I thought it was interesting but not significant in terms of my autism research and was disappointed that there was no mention of EFM. I also re-read a 2014 study by McClintic, et al, that found mice exposed to prenatal ultrasound exhibited behavior similar to that of people with autism and ADHD. Like the 2006 Rakic study, it found the effect only occurred in mice that had undergone a 30-minute ultrasound exposure. At this point, I looked for additional information regarding labor duration and discovered Albers’ 1999 study, “The Duration of Labor in Healthy Women,” which found that the statistical limits of labor in low-risk pregnancies had doubled. I then looked into the time differential between rodent and human lives, as described in Agoston’s 2017 paper, “How to Translate Time? The Temporal Aspect of Human and Rodent Biology,” which confirmed for me that 30 minutes in a mouse existence was in keeping with the longer labors experienced by more women in recent decades. That is when I decided to zero in on continuous EFM during prolonged labor as a combined risk factor for autism, since EFM was: 1) a form of ultrasound, which had been proven to disrupt neuronal migration in the fetal mammalian brain and 2) had been widely adopted as a means of monitoring labor at the same time 3) some labors were lasting much longer and 4) autism prevalence was inexplicably increasing.

I want to clarify that I am not suggesting that either EFM or prolonged labor – which has no doubt been with us since the beginning of time – are autism risk factors by themselves but rather in combination. Even so, simply measuring continuous EFM and labor duration will not necessarily produce consistent results because the exact placement of the ultrasound transducer and/or movement of the fetus during prolonged exposure could also increase or decrease any effect.

Do you now believe that prenatal ultrasound is safe?

I would still urge obstetricians and expectant mothers to avoid ultrasound sessions or proceed with restraint. It may be that EFM during prolonged labor presents the greatest autism risk factor, but that does not exonerate other potential causes, including diagnostic ultrasound. A small percentage of cases, such as fragile X syndrome, are known to be caused by a single-gene mutation, so there remains known inherited risk. There are also promising leads regarding genetic areas and variations of interest. Principal investigator of the Childhood Autism Risks from Genetics and the Environment (CHARGE) study Irva Hertz-Piciotto and her colleagues have found that maternal fevers, traffic-related air pollution and agricultural pesticides increase autism risk, among other findings. The difficulty is that even when added together, these other identified risk factors cannot explain the exponential increase in autism from 1 in 10,000 to 1 in 54 in just a few decades, so the search is still on for the driving force behind this trend.

Plus, we still do not know what caused the emergence of the first clusters of autism, identified independently by Drs. Kanner and Asperger on two continents in the 1940s, which predated both prenatal ultrasound and EFM. At about the time these two cohorts would have been in gestation, early versions of the electric blanket lacking thermostats were introduced as luxury consumer products in both the United States and overseas (“Electric Blanket.” How Products Are Made. 13 Jan. 2021. Accessed 1-16-2021), which I have long suspected might have induced these initial cases. Although electric blanket temperature controls have become quite sophisticated since then, the possibility that heated blankets could affect some expectant mothers during the first trimester might shed light on a 2011 CHARGE study that found children conceived in the winter months had a 6% greater risk of being diagnosed with autism than those conceived in the summer.

What roadblocks have you found in doing your research/publishing?

My biggest research roadblock has been obtaining papers that are behind a paywall, a situation that has improved greatly in the last several years due to rules pertaining to publicly funded research and the trend to provide authors the opportunity to pay a fee to make their work open access. As for publishing, I have found the real battle is getting people to read and respond to it once it is published – something all too many researchers encounter.

What about your original idea concerning CNVs and autism?

I do not plan to pursue that any further, although I hope someone with a background in genetics will because I believe it will do much to explain exactly why ultrasound may be a risk factor for autism and other developmental disorders. I suspect the consequences of a prolonged unnatural energetic exposure extends further than disrupting neuronal migration to genetic disruptions and is probably dose related. This could explain why the siblings of children diagnosed with autism often express some of the same traits that are not pronounced enough to land them on the spectrum. I would compare it to what we are learning about coronavirus exposure: More mildly affected individuals apparently had a lower viral load.

What do you see as the next step regarding this possible autism risk factor?

If the combination of continuous EFM during prolonged labor is responsible for today’s high autism rate, that is actually great news because the alternative way to monitor labor, intermittent EFM, is already deemed safer for both mother and child as it results in fewer unnecessary C-sections. That said, this is only a hypothesis and needs to be tested. My paper proposes five different ways to test the hypothesis. I am sure there are more – what is needed is the interest and funding necessary to take it to the next level. Until such research is undertaken, I would advise all pregnant women to take the proven safest route of having intermittent versus continuous EFM. If the majority of women opt for intermittent EFM, there might be push-back because it would likely require additional hospital training and staffing. However, if this practice reduces the prevalence of autism it would save literally billions of dollars in costs related to diagnosing, treating, educating, and the sometimes-necessary lifetime care of people with autism – not to mention saving the heartache experienced by so many families when they discover they have a child with special needs.

2 responses to “Caroline Rodgers: Autism, Prenatal Ultrasound, and Electronic Fetal Monitoring

  1. Caroline thanks for sharing your ideas.I would like to share my observations about ultrasound in particular US thermal index ,use as estimations of temperature during prenatal US imaging . Fetus real time core temperature is ignored during US examination.Ultrasound can’t increase significantly the mother temperature but US is directly focus to the fetus in a 100% humidity environment that difficult fetus cooling process.Fetus over heating during US examination for me is the explanation for the increase of ASD and it comorbidities.I’m not excluding US mechanical effects, many of them are well described, of this equation, but considering that ASD identification preceded ultrasound, vaccines, microwaves and antibiotics, I focus my attention in what they share in common ,heat generation(like electric blanket).Ultrasound is a quick heat producer. Before all of this factors, fever induced by infection and environmental factor like sun(heat stroke) in my opinion could be natural triggers of ASD.Temperature increases no matter the source are dangerous for the fetus.Fetus enzymes are the weakest link of this structure in construction. Temperature of 40°C and above are capable to inactivated or destroy human enzymes.Most human enzymes denaturation take place in temperature of 40°C or above.Many processes in a developing fetus can be affected.Since 1992 FDA guidances allow the use of high frequencies ultrasound capable of generated thermal indexes from 38°C to 43°C. Deep ultrasound is a physical phenomena capable to over heat a fetus and destroy one of it basic building block , enzymes.
    Depending in which period of gestation and how many times during gestation fetus is over expose to heat of 40°C or above, a different mix of damages is going to be produced, for me the Spectrum and it comorbidities.Thank again for sharing your work.


  2. Pingback: Autism and CTG monitoring: an interesting theory – Birth Small Talk·

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