- The Trump administration believes evidence shows autism is linked to use of acetaminophen early in pregnancy.
- Health and Human Services agencies are putting lots of research into understanding and preventing autism.
- The administration may also suggest that a drug that protects against cancer drug could treat autism.
During what he’d promised would be an “important announcement,” President Donald Trump on Monday linked autism to use of Tylenol and other acetaminophen-based products during pregnancy.
The Washington Post had previewed the announcement earlier, citing four sources “with knowledge of the plans who asked for anonymity” to talk about it in advance. Those same sources said he would also suggest a drug used to counter certain cancer treatments could help treat autism.
The president cited a review of previous research conducted by Mount Sinai and Harvard researchers that found a potential association between acetaminophen use early in pregnancy and increased risk of autism in children. The researchers suggested Tylenol and similar products should not be used early in pregnancy except in the case of fever.
Leucovorin is the possible treatment. It’s usually prescribed to counteract some medication side effects and to treat a vitamin B9 deficiency. “Early double-blind, placebo-controlled trials administering leucovorin to children with autism have shown what some scientists describe as remarkable improvements in their ability to speak and understand others,” per the Post.
While in Arizona Sunday for the memorial of Charlie Kirk, the conservative political activist killed at a campus event in Utah, Trump had promised the upcoming autism announcement would be “one of the biggest” medically in U.S. history. “I think we found an answer to autism,” he said, calling acetaminophen “a very big factor” in the increased risk of autism.
Acetaminophen is called paracetamol outside of North America.
The study finding a potential link between autism and acetaminophen was published in July in the journal Environmental Health. It noted that acetaminophen is the most commonly used nonprescription pain and fever medication during pregnancy. “Appropriate and immediate steps should be taken to advise pregnant women to limit acetaminophen consumption to protect their offspring’s neurodevelopment,” the researchers wrote.
They said they found a “strong, consistent association between prenatal acetaminophen exposure” and neurodevelopmental issues, but added that because of study limitations, they could not prove “definitive causation.” Per the researchers, “We advocate cautious, time-limited acetaminophen use under medical guidance, highlighting the need for research into safer alternatives and updated guidelines.”
Going after the causes of autism
The NIH has been tasked with studying autism and will reportedly announce that 13 teams have grants to study the causes and treatments — and to verify past findings.
The administration touting a potential link to acetaminophen was somewhat surprising, as Secretary of Health and Human Services Robert F. Kennedy has repeatedly linked vaccines to autism. Last week, Dr. Robert Malone, a new member of the Centers for Disease Control and Prevention’s vaccine advisory committee, told One America News Network he believed Kennedy would link all three: Tylenol, vaccinations and autism.
Kennedy had pledged that the urgent push for answers would yield some findings by September.
In an email to NBC News, Andrew Nixon, a health and human services spokesperson, wrote, “We are using gold-standard science to get to the bottom of America’s unprecedented rise in autism rates. Until we release the final report, any claims about its contents are nothing more than speculation.”
Fever or pain in pregnancy
Pregnant women have been told for years that in case of fever or pain, Tylenol and generic acetaminophen are the safest over-the-counter options. Advil and generic ibuprofen have been linked to birth defects and risk of miscarriage.
Kenvue, which makes Tylenol, said by email to NBC before the formal announcement that “nothing is more important to us than the health and safety of the people who use our products. We have continuously evaluated the science and continue to believe there is no causal link between acetaminophen use during pregnancy and autism.”
Kenvue told BBC in a statement that “we believe independent, sound science clearly shows that taking acetaminophen does not cause autism. We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers.”
What we know about autism
Autism spectrum disorder covers a range of symptoms, from mild to severe, that impact social communication and language development. Repetitive behavior is also typically an aspect of the disorder.
It has been widely believed that autism is caused by a complex mix of genetic and environmental factors. The Post reported that “some experts had recently considered (autism) predominantly genetic and therefore largely untreatable.”
The CDC said this spring that autism rates have been increasing dramatically. In 2000, 1 in 150 U.S. children at age 8 were diagnosed with autism; in 2022, the share had increased to 1 in 31.
Some believe cases haven’t increased that much, but instead that experts are becoming better at identifying autism spectrum disorder.
As Politico noted, “Kennedy believes environmental factors are causing the rise in autism cases — despite ample evidence to the contrary, he suspects vaccines are involved — while many public health experts believe it’s because of changing diagnostic criteria and more attention to the condition.“
The American College of Obstetrics and Gynecology has deemed acetaminophen safe for pain relief in pregnancy.
“Studies that have been conducted in the past show no clear evidence that proves a direct relationship between the prudent use of acetaminophen during any trimester and fetal developmental issues,” the group said in a consensus statement in 2021. “Neurodevelopmental disorders, in particular, are multifactorial and very difficult to associate with a singular cause.” It notes that since brain development is ongoing for some time, that “leaves room for children to be exposed to a number of factors that could potentially lead to these issues.”
JAMA Network in April published an international study by researchers in Stockholm, Sweden, and in Philadelphia that looked at use of the fever-reducing drug as a risk factor for autism, attention deficit/hyperactivity disorder and intellectual disability.
Initially, the researchers found “marginally increased risk of autism and ADHD associated with acetaminophen use during pregnancy.” When they analyzed matched sibling pairs, they found no such risk associated with autism, ADHD or intellectual disability from acetaminophen use.
“This suggests that associations observed in other models may have been attributable to confounding,” they wrote.
Confounding refers to a “spurious association,” per Oxford. Things appear to be linked but there’s actually something else that’s not identified going on.
What is leucovorin?
Leucovorin is a cancer and anemia drug that the Trump administration touts as a possible treatment for autism, too. Leucovorin is a form of vitamin B9, which is commonly called folate.
According to Medline Plus, leucovorin is used to prevent “harmful effects of methotrexate” when that cancer chemotherapy medication is used. It belongs to a class of medications called folic acid analogs and “works by protecting healthy cells from the effects of methotrexate or similar medications, while allowing methotrexate to enter and kill cancer cells.”
The Washington Post reports there’s real, but “fragile” hope in using leucovorin to treat autism. The article tells the story of Nathaniel Schumann, who at 8 had autism and was nonverbal. The story said that two weeks after he first received the study pill, he spoke in full sentences.
The article said that studies have shown those with autism have trouble transporting folate to the brain and it is essential for brain development. The belief is leucovorin may help with its delivery.
But researchers are calling for more study and Richard Frye, a pediatric neurologist who studies the drug, said he’s hopeful it will help, but the research is still early.
The Autism Science Foundation said more studies are needed and that it’s too soon to recommend it to treat autism.
“I don’t think you should go out and use it right now based on the body of evidence that exists, but it’s certainly worthy of further exploration,” Scott Gottlieb, a former FDA commissioner, said in an interview on CNBC’s “Squawk Box” on Monday.