After Trump warned about Tylenol and autism, researchers found no link

“Don’t take Tylenol. Don’t take it. Fight like hell not to take it.”

That was President Donald Trump’s message when he and Health Secretary Robert F. Kennedy, Jr., announced in September that women should avoid Tylenol during pregnancy because of what they described as a link to autism.

The risk had not been supported by solid scientific evidence when Trump issued the warning. Now, a group of researchers has responded with what may be the most in-depth analysis yet of the existing science on the subject.

Their study, published Friday in the medical journal The Lancet Obstetrics, Gynecology, & Women’s Health, found no link between acetaminophen — the active ingredient in Tylenol, also known as acetaminophen — taken during pregnancy and autism, attention-deficit/hyperactivity disorder, or intellectual disability.

The authors said they undertook the research, in part, to clear up confusion that followed Trump’s statements, since untreated fever can pose health risks to both mother and baby.

“After this statement, many mothers were afraid to take paracetamol,” said Dr Francesco D’Antonio, one of the paper’s authors and a professor of fetal medicine at the University of Chieti in Italy. “The day after that statement, in fact, we had a massive increase in phone calls and emails from women. »

The main takeaway from the report is that acetaminophen is safe during pregnancy, according to Dr. Asma Khalil, another author of the paper and a consultant obstetrician and fetal medicine specialist at St. George’s Hospital in London.

“This remains the first-line treatment we would recommend if pregnant women experience pain or fever,” she said in a call with reporters.

In a press release, The Lancet called the paper a “gold standard evidence review.”

The description echoes language from members of the Trump administration. In the September announcement, Kennedy said the National Institutes of Health would pursue “unbiased, depoliticized, gold-standard scientific research and academic freedom” in its investigation into the causes of autism.

Four researchers not involved in the new paper praised its rigor.

“I don’t think there’s a better way to analyze the data than this Lancet article,” said David Mandell, a professor of psychiatry at the University of Pennsylvania.

The seven-person team behind the new paper, from the United Kingdom, Italy and Sweden, used three methods to evaluate studies published through September.

First, they excluded studies that did not compare pregnancies in which Tylenol was used to those that did not, as well as research that did not disclose the pregnant women’s health histories or the medications they took. They also did not include studies that asked women to self-report whether they took Tylenol and whether their child had autism. Instead, researchers relied only on studies using medical records or questionnaires administered or reviewed by a health care provider. Out of thousands of studies, 43 were retained.

Next, the researchers evaluated the studies based on their quality and the possibility that factors may have biased the results. They excluded low-quality studies, such as those that didn’t follow study participants for very long or didn’t clearly define health outcomes.

Finally, they conducted a more in-depth evaluation of the two most robust studies on Tylenol use and autism, each comparing large groups of siblings – one who had been exposed to Tylenol in utero and the other who had not. The siblings shared genetics and had been raised in roughly the same environment, with the same socioeconomic and educational backgrounds, so the researchers could assume that these factors did not influence the study results.

All three methods came to the same conclusion: There was no link between Tylenol use during pregnancy and neurodevelopmental disorders.

“No matter how they analyze it, they find that acetaminophen does not cause ADHD, autism or intellectual disability,” Mandell said.

Asked about the findings, a Department of Health and Human Services official said the analysis does not resolve the question of whether Tylenol use is linked to autism. The official alleged that the journal constructed a conclusion by excluding evidence and designing a study with a bias toward showing no association.

“According to HHS, many experts have expressed concern about the use of acetaminophen during pregnancy,” said Andrew Nixon, a department spokesman.

Nixon named, in particular, Dr. Andrea Baccarelli, dean of the faculty at the Harvard TH Chan School of Public Health, whose study last year, published in the journal Environmental Health, found an association between autism and Tylenol use during pregnancy. The Trump administration cited the research as evidence of Tylenol’s purported risks. Baccarelli did not respond to a request for comment.

Khalil said Baccarelli’s analysis and other small studies that found such associations probably didn’t do enough to rule out confounding factors.

Mandell also said that Baccarelli’s analysis did not comb through as many articles as the new analysis.

“At the very least, it suggests sloppy research,” he said.

In the months since his initial statements about Tylenol, Trump has doubled down on his efforts, writing on Truth Social earlier this month: “Pregnant women, DO NOT USE TYLENOL UNLESS ABSOLUTELY NECESSARY.” »

However, a written warning the Food and Drug Administration sent to doctors — which Trump and Kennedy announced in September — just said to “consider minimizing the use of acetaminophen.” The warning also said the drug remained the safest over-the-counter option for reducing pain and fever during pregnancy and described the supposed association between Tylenol and autism as “an area of ​​ongoing scientific debate.”

Autism researchers say there is no reason to debate the subject any further.

“The question has been answered,” said Alycia Halladay, scientific director of the Autism Science Foundation, who was not involved in the new paper. “There has never been a relationship between acetaminophen and autism. We can stop talking about it now and focus on what causes autism instead of confusing families and continuing to blame the mother.”