Researchers involved in recent studies linking acetaminophen use to autism have criticized Donald Trump for misrepresenting their findings. 

Last month, President Trump and key health officials announced that pregnant women should avoid acetaminophen, known as Tylenol, suggesting it increases the risk of autism in their children.

He pointed to a study from August by experts from Harvard, Mount Sinai, UCLA, and the University of Massachusetts Lowell, which indicated a possible link between acetaminophen during pregnancy and neurodevelopmental issues such as autism and ADHD. 

The study’s researchers stressed more investigation is required and that the connection is merely associative, but Trump officials spoke conclusively, with FDA commissioner Dr. Marty Makary stating: ‘We now have evidence we cannot ignore.’

Experts from the study, published in BMC Environmental Health, expressed to the Daily Mail that, although they interacted with the administration and “value their interest in the research,” acetaminophen “continues to be crucial for pregnant patients and their doctors.”

They also urged Americans to heed advice from health authorities like the American College of Obstetricians and Gynecologists (ACOG), who have criticized Trump’s recommendations as “dangerous” and “deeply troubling.” 

And the authors of another widely regarded 2024 paper, which studied 2.5million children and found ‘no evidence’ of acetaminophen causing autism, told this website that the president’s statements are ‘not accurate.’

They also fear Trump’s messaging will cause confusion among parents and increase the risk of them avoiding acetaminophen in dire situations, such as a high fever or extreme pain.

President Donald Trump is pictured alongside Robert F Kennedy Jr and Dr Mehmet Oz lat month when the group advised pregnant women to avoid taking acetaminophen, sold under the brand name Tylenol

Dr Brian K Lee, one of the co-authors of the 2024 study and a professor of epidemiology at Drexel University, told the Daily Mail: ‘The best science to date indicates that acetaminophen use during pregnancy does not cause autism.

‘While there are several observational studies that have found a statistical association between acetaminophen and autism, association is not causation. 

‘In short, the President is spreading misinformation. One immediate concern which is already apparent is the number of persons out there who are confused by health messaging. Traditionally, we trust our authority figures to be able to inform us about what best to do. 

Dr Andrea Baccarelli, lead author of the August study referenced by Trump, is pictured here

‘Few people have the time or training necessary to sift through all the scientific evidence to decide what to do about every health matter. But when conflicting messaging happens… this causes confusion and uncertainty.’

Acetaminophen is widely used by pregnant women, with about 60 percent taking the drug, to reduce fevers and pain that could harm both mother and baby.

Acetaminophen, called paracetamol in Australia and the UK, is found in Tylenol and a number of other medications, including over-the-counter cold and flu drugs such as DayQuil and NyQuil and sleep aids such as Excedrin PM.

Kenvue, the makers of Tylenol, have pushed back against the Trump administration’s claims that the painkiller causes autism, branding it ‘dangerous’ and insisting its drug remains the safest option for pain and fever relief in pregnant women. 

A spokesperson told the Daily Mail: ‘The facts are that over a decade of rigorous research, endorsed by leading medical professionals and global health regulators, confirms there is no credible evidence linking acetaminophen to autism.

‘We stand with the many public health and medical professionals who have reviewed this science and agree. We will continue to explore all options to protect the health interests of American women and children.’

Researchers behind the BMC Environmental Health study cited by Trump conducted a review of 46 studies including 100,000 participants. Out of 46 studies, 27 found a positive association between acetaminophen and neurodevelopmental disorders like autism and ADHD. 

They suggested acetaminophen may cross the placenta, which delivers nutrients from mother to fetus, and induce oxidative stress that hinders neurodevelopmental pathways. 

Dr Andrea Baccarelli, lead author of the August study and professor of environmental health at the Harvard TH Chan School of Public Health, told the Daily Mail in a statement: ‘We found evidence of an association between exposure to acetaminophen during pregnancy and increased incidence of neurodevelopmental disorders in children. 

‘This association is strongest when acetaminophen is taken for four weeks or longer.’ 

He noted that animal studies have suggested prenatal exposure to acetaminophen can damage a developing brain. 

Dr Baccarelli also recommended caution against heavy or prolonged use of acetaminophen during pregnancy but emphasized ‘further research is needed to confirm the association and determine causality.’

However, he also acknowledged that ‘acetaminophen remains an important tool for pregnant patients and their physicians,’ as high fever in a mother can hinder fetal development. 

He said: ‘After assessing the evidence, my colleagues and I recommended a balanced approach based on the precautionary principle: Patients who need fever or pain reduction during pregnancy should take the lowest effective dose of acetaminophen, for the shortest possible duration, after consultation with their physician about their individual risk-benefit calculation.’

Dr Baccarelli told this website that his team discussed the findings with Kennedy and NIH Director Dr Jay Bhattacharya in recent weeks and that the researchers ‘appreciate their interest in the study.’

Tylenol maker Kenvue disputed Trump’s claims, branding them ‘dangerous’ and insisting its drug remains the safest option for pain and fever relief in pregnant women (stock image)

Mount Sinai Health System, where one of the BMC study author Diddier Prada is affiliated, told the Daily Mail in a statement: ‘The study found an association, but not a causal link, between prenatal acetaminophen exposure and an increased risk of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in children.

‘As the authors note, these do not prove that acetaminophen use during pregnancy causes these conditions but underscores the need for further research to optimize management of pain and fever during pregnancy using current or future medications.

‘The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) continue to recommend acetaminophen as one of the safest pain and fever treatment options during pregnancy when used as directed, and emphasize that pregnant patients should always discuss any medication use with their clinicians.’

ACOG, meanwhile, earlier this week slammed the Trump administration for linking acetaminophen use to autism. 

The agency said in a statement: ‘It is highly unsettling that our federal health agencies are willing to make an announcement that will affect the health and well-being of millions of people without the backing of reliable data.

‘In more than two decades of research on the use of acetaminophen in pregnancy, not a single reputable study has successfully concluded that the use of acetaminophen in any trimester of pregnancy causes neurodevelopmental disorders in children.’

A 2024 study published in JAMA, meanwhile, was cited in the BMC report and found no association between acetaminophen and autism.

The study included 2.5million children born in Sweden between 1995 and 2019 who were followed up with through 2021. Of those, 7.5 percent were exposed to acetaminophen while in utero. 

The team initially found that children who were exposed to acetaminophen during pregnancy had a slightly increased risk of autism, ADHD and other neurodevelopmental disorders than those not exposed. However, when they compared those children to their siblings, the increased risk disappeared. 

Hugo Sjöqvist, JAMA study author and PhD student at Karolinska Institutet, told the Daily Mail: ‘I fail to see the reasoning as to why one would claim that acetaminophen would lead to autism. The science is quite clear on this topic. 

‘It is also important to remember that the usage of acetaminophen is not random – it’s used when you are sick, in pain, etc. Therefore, drawing conclusions by simply looking at the usage and outcome can even be seen as a bit disingenuous. 

‘It is my hope that people do not unnecessarily abstain from pain relievers, as it will cause unnecessary pain, stress and discomfort.’ 

Dr Viktor H Ahlqvist, lead author of the JAMA study, told the Daily Mail that Trump’s statements regarding acetaminophen and autism are ‘not accurate’

Sjöqvist explained that sibling studies like his team’s help address limitations of other studies by adding additional information like genetic risk and environmental exposures, which are also linked to autism. 

He pointed to a Japanese study published earlier this month that replicated his team’s findings. Looking at 217,000 children from 2005 to 2022, those researchers noted a small increase in autism risk among children whose mothers took acetaminophen while pregnant. 

However, there was no effect when looking at sibling comparisons. 

Dr Viktor H Ahlqvist, lead author of the JAMA study and postdoctoral researcher in the Institute of Environmental Medicine at Karolinska Institutet in Sweden, told the Daily Mail that Trump’s statements regarding acetaminophen and autism are ‘not accurate.’ 

He said: ‘There have been smaller studies and animal examinations that suggested some increased risk. However, larger population-based studies from Sweden, Norway, and Japan suggest that this initial observation was biased.’

Dr Ahlqvist also fears pregnant women will forgo the use of acetaminophen in needed situations, such as if they are suffering from a high fever.  

He told this website: ‘I also think that these announcements stigmatize and puts blame on pregnant women and families of children with autism, when there is no evidence to support it.’

‘There is no strong evidence to suggest acetaminophen used in pregnancy would cause autism. However, as with any medication use in pregnancy, best advice is always to consult with physicians and midwifes – taking medications during pregnancy is always best done in light of expert advice. 

‘Trump is not a source of expert advice.’