Many of us will remember where we were on September 11th, 2001, I remember because the first reports that came out, were that the world trade center had been hit.  My husband worked in the WTC, but it was another WTC, the one on the Berrini in São Paulo,  Brazil.  So, for us as a family, we felt empathy and sadness but we were also grateful.  

The Absence of Scientific Evidence Linking Acetaminophen (Tylenol) to Autism

As a pregnant person, a soon mother to be, you are already vulnerable to the kindness of strangers, who constantly feel the need to criticise well, pretty much everything you do or don’t do. 

There is suddenly a social norm that isn’t explained to a pregnant person which is that, complete strangers are allowed to ask you personal and invasive questions; it’s suddenly acceptable for people to touch you without permission; the only possible assumption made, is that being the personal producer of another human being is truly delightful. 

You are bombarded by advise, by experts. 

When you have to deal with the complexity of the physical changes and all of the emotional baggage of pregnancy, everything seems like Sophie’s choice.  Dammed if you do, dammed if you don’t.

Now you have to decide between physical pain and listening to your medical team or for ever be blamed for your autistic (possible) child, because you were selfish enough to take something for your pain and listened to your medical team.

Acetaminophen is a common pain reliever, one that’s been considered safe for decades, and in fact developed in 1878 by Harmon Morse and entered main stream clinical use in 1955. 

Tylenol, the brand name for acetaminophen, was first introduced by McNeil Laboratories in 1955, used by prescription only, for children.   Johnson & Johnson acquired McNeil in 1959, and Tylenol was approved for sale without a prescription afterward. 

The harmful harmful narrative that emerged from September the 22nd 2025 White House announcement,  has created unnecessary fear and confusion among millions of families. As we examine the overwhelming scientific evidence, one fact becomes crystal clear: Autism is complex.

We professionals are better trained, better informed and that is one of the many reasons that diagnoses are perceived as being on the up. 

The recent claims linking acetaminophen (Tylenol) use during pregnancy to autism represent a dangerous oversimplification of hugely complex neurodevelopmental processes.    

And threaten to resurrect the damaging practice of blaming mothers for their children’s well, anything really,   we go back to times in which fully grown adults are blaming their mothers for their inability to exercise any self control, or being unable to be half way decent human beings. 

When we scrutinise the actual research, rather than cherry-picked studies or misinterpretations, the evidence strongly refutes any causal relationship between this essential medication and autism spectrum disorder.

The Devastating Return of Maternal Blame, which is to say the Resurrecting of Old Wounds.

For me as a neuropsychologist, the most insidious aspect of the Tylenol-autism claim isn’t just its lack of scientific data, it’s the way it resurrects the historically damaging practice of blaming mothers for their children’s autism.

For decades, families endured the devastating so called refrigerator mother theory, which falsely suggested that cold, unloving mothers caused their children’s autism.

This harmful myth was finally (ish) debunked, but the Tylenol claims threaten to bring back that same maternal shaming in a new form.

Mothers the message is crystal clear: YOU ARE TO BLAME if you have an autistic child.  Because you were incapable of dealing with a headache. 

Some of you might know, I had a very serious accident when I was pregnant with my youngest, I had to endure excruciating back pain for months during the pregnancy and afterwards.  I had physiotherapy for several years. 

I refused to take any medication as I was already racked with guilt that I had a car accident whilst pregnant, how utterly irresponsible of me to drive and work.  It took me years to deal with the trauma.  

Now, my youngest as some of you know, is my amazing autistic adult child.  Can you conceive of the overwhelming guilt that I would now be dealing with if I had taken medication?

Let’s look at  Real-World Impact on Families

This renewed maternal blame creates a cascade of harmful consequences that extend far beyond individual families. Mothers who used acetaminophen during pregnancy may now question whether they caused autism.   

This guilt can interfere with the crucial bonding process between parent & child and can delay acceptance for a diagnosis. 

Then lack basic support. 

But let’s think about the broader implications, which are just as equally concerning.

Pregnant women may avoid necessary fever reduction, risking genuine harm to their developing babies.

Shame, guilt may lead to depression, social isolation, public shaming, which may lead to many more problems, including suicidal ideation and suicide.

Families may waste precious time and resources pursuing ineffective cures based on false premises.

Public trust in legitimate medical guidance erodes, or really simply disappears, potentially affecting other health decisions.

The autism community faces renewed stigmatization, misunderstandings, and risk being ostracised.

Let’s look at some of the science behind the statement.

A few different studies were used, and whilst I read over 100 studies in the last 36 hours, I’m only going to write about

In terms of the numbers

Khan, et al., 2022, found 35,285 studies found on the subject, an automated process filtered out 32,780, leaving, 2,503, then another process removed another 2,433 papers, and then so on until there were 16 papers left, which confirmed what the researchers wanted.  

The Navigation Guide systematic review that Trump administration officials cited actually undermines their own argument when examined critically.   46 studies identified, 27 showed positive associations, 9 showed no association, and 4 showed protective effects.

Interestingly enough, the highest-quality studies with the most sophisticated methodologies were those least likely to show associations.

The review authors themselves acknowledged severe methodological limitations in many included studies:

Confounding by indication: Women who take acetaminophen may have underlying conditions (infections, fever, pain) that are themselves risk factors for autism

Exposure misclassification: Many studies relied on maternal recall years after birth, creating substantial measurement error.

Genetic confounding: Mothers with genetic predispositions to autism may be more likely to experience pain and use acetaminophen.

Selection bias: Retrospective studies may systematically exclude certain populations.

A little side note on what’s Association vs. Causation?

Even studies showing statistical associations between acetaminophen use and autism fail to establish causation, this a crucial distinction that the Trump administration’s claims deliberately obscured.

The scientific community requires multiple lines of evidence to establish causation, including the following:

1. Temporal relationship: Exposure must precede the outcome. ✓
2. Dose-response relationship: Higher doses should increase risk. ✗
3. Biological plausibility: A credible mechanism must exist. ✗
4. Consistency across studies: Results should replicate in different populations. ✗
5. Absence of confounding: Alternative explanations must be ruled out. ✗

Acetaminophen-autism studies fail most of these criteria, particularly when subjected to rigorous methodological controls.

Let’s add some science and look at the Overwhelming Scientific Evidence Against Causation

Swedish Sibling Control Studies

The most compelling evidence against the Tylenol-autism link comes from sophisticated sibling control studies that address the fundamental methodological flaws plaguing earlier research. This landmark 2024 Swedish study by Ahlqvist, et al., represents the largest longitudinal in this field, analyzing 2 480 797 children born between 1995 and 2019, with follow-up through December 31, 2021.

Out of these 2 480 797,

        “185 909 children (7.49%) were exposed to acetaminophen during pregnancy. Crude absolute risks at 10 years of age for those not exposed vs those exposed toacetaminophen were 1.33% vs 1.53% for autism, 2.46% vs 2.87% for ADHD.”

Ahlqvist et. al., 2024

Conclusion from this study.

No association between acetaminophen use during pregnancy and autism when using sibling controls (HR = 0.98, 95% CI 0.93-1.04)

        “Acetaminophen use during pregnancy was not associated with children’s risk of autism, ADHD, or intellectual disability in sibling control analysis.”

Ahlqvist et. al., 2024

The absolute brilliance of sibling control studies lies in their ability to control for shared genetic and environmental factors that can confound traditional observational studies. When the same mother has multiple pregnancies, some involving acetaminophen use and others not, researchers can isolate the drug’s effects from family-level confounders like genetics, socioeconomic status, and parental characteristics.

Multiple Independent Confirmations

The Swedish sibling control findings weren’t isolated, they’ve been replicated by independent research groups using different populations and methodologies. For example Japanese sibling control study published in September, 2025 reached identical conclusions, finding that apparent associations disappeared when controlling for family factors.

These convergent findings across different healthcare systems, populations, and study designs provide powerful evidence against causation. If acetaminophen was truly the cause, then consistent associations who be seen, regardless of study methodology, but gosh that’s not the case.

The one thing that medical community did was swiftly condemn the misinformation, and pretty much every major professional organization has issued statements contradicting this administration’s position. 

Such as the statement from the American Psychiatric Association below.

“It is essential that the administration prioritizes evidence-based support for individuals on the autism spectrum and invests in long-term comprehensive research about the disorder. Vaccines do not cause autism. Claims of any such association have been repeatedly discredited in peer reviewed studies. Autism is a complex disorder, and it is incorrect to imply that a handful of studies have established causation. A strong base of evidence shows that acetaminophen, when taken as directed, is safe for use during pregnancy. Any decisions around a course of treatment should be determined by a patient and their doctor.”

American Psychiatric Association press announcement.

I’m summing up now,  because even to write this much, it’s been a herculean effort.

Autism is so complex that no one thing can be used to explain the whys and wherefores. 

Being a parent is hard enough. 

Blaming and Shaming Moms is NOT ACCEPTABLE.

The damage has been done, this will have global repercussions for years to come.

And so why did I start with September 11th, 2001?

Because I was grateful to not be dealing with so many different things from this administration, just as I was truly grateful for my husband to have been working in another WTC on September 11th, 2001, but we, myself included,  in the health care community are paying for our complacency, and we risked lives from now on. 

We were warned in April 2025 that the cause | cure for autism, would be found by September 2025, and we sat on our heels in the smug belief that was obviously not going to happen.  Research takes years, it’s impossible.

We did not pay enough attention, we did not do enough to prevent this administration’s position.

I end with a couple of paraphrased quotes from two very wise ones.

“We allowed our arrogance to blind us to the threat. We underestimated the Goa’uld.”

Thor from Asgard in Stargate.

“In their arrogance the Ancients allowed the Wraith to evolve. As advanced as they are, they should have seen the potential problems of the Wraith long before the Wraith were powerful enough to be dangerous, but they were blinded by their own arrogance.” 

Ancients in Stargate Atlantis

Let us learn from our own arrogance and stem this continuous tide of misinformation which has created unnecessary fear and confusion. 

                        “Disguise, I see thou art a wickedness, wherein the pregnant enemy does much.”

12th Night

                        (Does Puck) “Mislead night-wanderers, laughing at their harm?”

A Midsummer Night’s Dream

  William Shakespeare

We know not all the reasons why this misinformation and announcements were made, but the laughing at their harm caused, may be one of them.  

I certainly hope not, as I already dread the next wave of announcements. 

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