Trump Administration Ties Tylenol in Pregnancy to Autism, Launches Vaccine Investigation

President Donald Trump, HHS Secretary Robert F. Kennedy Jr., and other cabinet officials held a press conference to discuss what they have learned so far regarding the underlying environmental factors that are contributing to the sharp rise in autism in the United States. The primary focus of the press conference was on acetaminophen, most commonly known under the brand name Tylenol. There were also discussions of mercury and aluminum adjuvants in childhood vaccines.

FDA Commissioner Dr. Marty Makary said the agency will be requiring new labels for acetaminophen and all doctors will be required to provide informed consent regarding potential harms to pregnant mothers.

“We now have data we cannot ignore,” Commissioner Makary said. “There’s a very large study, the Boston birth cohort, with researchers from Johns Hopkins, my former institution, and Boston University, who found ‘consistent associations between acetaminophen in pregnancy and autism.’ And the nurse’s health study with researchers from Yale, Columbia, and Harvard looking at 9,000 kids found that acetaminophen use in pregnancy was associated with neurodevelopmental disorders. And four weeks ago, a Mount Sinai Harvard study reviewed all the existing literature and found the overwhelming body of evidence points to an association.

In addition to the announcement regarding the potential association with acetaminophen use during pregnancy and autism, the federal health agencies are engaged in an “unprecedented all-agency effort” to identify all causes of autism and potential treatments for individuals with autism spectrum disorder. Last week, The HighWire reported that HHS is commissioning a study to determine if there is a link between vaccines and autism.

In April, Secretary Kennedy announced the effort of HHS to identify environmental causes while calling out the mainstream media for pushing the narrative that the rise in autism is almost fully attributable to improved diagnostic testing and expanded parameters for what is classified as autism.

Kennedy countered those claims once again during the press conference. “That’s one of the canards that has been promoted by the industry for many years, that it’s a change in diagnostic criteria, better recognition, but there’s been study after study that completely debunks that – one of them by the Mind Institute at UC Davis University of California. But also, it’s just common sense because you’re only seeing this in people who are under 50 years of age. If it were better recognition or diagnosis, you’d see it in 70-year-old men. I’ve never seen this happening in people my age. I’ve never seen a case of full-blown autism, and that means profound autism. I want to be very careful. Head banging, stimming, toe walking, nonverbal, non-toilet trained. I’ve never in my life seen a 70-year-old man who looks like that. You’re only seeing it in kids. It’s an epidemic.”

NIH Director Jay Bhattacharya and Secretary Kennedy both refuted the claim that autism is a genetic disorder that is not caused by environmental factors. “For too long, it’s been taboo to ask some questions for fear the scientific work might reveal a politically incorrect answer,” Director Bhattacharya said. “Because of this restricted focus in scientific investigations, the answers for families have been similarly restricted, often pointing families to behavioral therapies that don’t work for every kid or suggest non-modifiable genetic factors as the cause. But genetics alone can’t explain such a sharp rise in autism prevalence over just a few decades.”

Kennedy said the NIH has focused primarily on “fruitless research about the genetic drivers of autism,” stating it would be like studying genetic factors of lung cancer without investigating the role of cigarettes. Kennedy said federal health agencies have spent 10 to 20 times more on studies regarding genetic factors of autism than they have on environmental factors. He called the research into the link of autism and genetic factors a “dead end.”

During yesterday’s press conference, Kennedy also announced Leucovorin will be approved by the FDA as a treatment for autistic individuals and will be covered by Medicaid and CHIP.

“Peer-reviewed literature has documented that up to 60% of folate-deficient children with ASD can have improved verbal communications if given Leucovorin,” Kennedy said. “I have instructed NIH, FDA and CMS to help doctors treat children appropriately.”

Kennedy said all of the health agencies are actively looking into potential connections between vaccines and autism. He said that it will take some time for scientists to honestly evaluate the potential connection, but the administration will be “uncompromising and relentless in our search for answers.”

“Some 40 to 70% of mothers who have children with autism believe that their child was injured by a vaccine,” Secretary Kennedy said. “President Trump believes that we should be listening to these mothers instead of gaslighting and marginalizing them like prior administrations… We will perform the studies that should have been performed 25 years ago. Whatever the answer is, we will tell you what we find.”

President Trump referred to the Amish community as an example of a group that has “virtually no autism.” Kennedy clarified that there are subsets of the Amish community that do not vaccinate, but the Amish community has low rates of chronic disease “across the board,” including the subsets that do vaccinate.

A 2024 JAMA study of over two million children concluded that acetaminophen use during pregnancy is not associated with a higher risk of autism in children. A 2025 Environmental Health study published last month came to the opposite conclusion, stating “Our analyses using the Navigation Guide thus support evidence consistent with an association between acetaminophen exposure during pregnancy and increased incidence of NDDs. Appropriate and immediate steps should be taken to advise pregnant women to limit acetaminophen consumption to protect their offspring’s neurodevelopment.” Both studies were peer-reviewed.

The Environmental Health study critiqued the methodology of the JAMA study, stating that the authors only reported a 7.5% use of acetaminophen during pregnancy, despite 50% being reported globally. The authors said the JAMA study relied on structured interviews with midwives and didn’t specifically inquire about acetaminophen use.

“Sure, you’ll be able to find a study to the contrary. That’s how science works,” Commissioner Makary said. “But to quote the dean of the Harvard School of Public Health, ‘there is a causal relationship between prenatal acetaminophen use and neurodevelopmental disorders of ADHD and autism spectrum disorder.’”

“Sure, you’ll be able to find a study to the contrary. That’s how science works,” Commissioner Makary said. “But to quote the dean of the Harvard School of Public Health, ‘there is a causal relationship between prenatal acetaminophen use and neurodevelopmental disorders of ADHD and autism spectrum disorder.'”