President Trump and Secretary of Health and Human Services Robert F. Kennedy Jr. they held a press conference and strongly advised against the use of Tylenol (acetaminophen) during pregnancy.
They associated its use with the development of autism and other neurological developmental disorders of childhood. Trump released the script, declaring that “we found the cause of autism,” repeatedly advising against the use of Tylenol during pregnancy, saying, “just tough.” He went on to state that babies should also not receive Tylenol and then ventured to question current childhood vaccination schedules.
The press conference was chaotic and reckless, resulting in misinformation and confusion. Trump’s conclusion that Tylenol use during pregnancy was “very high risk” and “strongly associated with autism” goes beyond what the scientific evidence supports. Studies have found an inconsistent association, and no study supports a causative relationship.
Association is not causation. It is impossible to conduct prospective placebo-controlled studies (the “gold standard” for demonstrating causation) for the use of Tylenol during pregnancy for obvious ethical reasons. All studies are retrospective and observational.
Observational studies are loaded with confounding variables that can make an association appear causative. For example, the senior author of an April 2024 study in the Journal of the American Medical Association, widely considered the definitive research on the use of Tylenol during pregnancy, offers this scenario: Eating ice cream in the summer is statistically associated with the risk of drowning. In fact it is warm weather that increases both ice cream consumption and swimming (which increases the likelihood of drowning).
Packages of Tylenol are seen at a pharmacy in Houston, Texas, on September 23, 2025. US President Donald Trump on September 22, 2025 urged pregnant people not to take Tylenol over an unproven link to autism, and urged major changes in the standard vaccines given to babies.
Likewise, conditions that trigger the use of Tylenol, such as fever and infection during pregnancy, have been linked to autism and other neurodevelopmental conditions if left untreated. These could plausibly be the actual causative factors.
Observational studies can indicate causation, but only when there is an enormous amount of irrefutable evidence over time. Smoking causing lung cancer is an example. The use of Tylenol during pregnancy is very far from this level of evidence. A recent review in Environmental Health of 46 studies showed conflicting results regarding an association. Some studies that found an association have been criticized for a lack of scientific rigor and study design.
The aforementioned JAMA article was a Swedish study of 2.4 million children over 24 years. The study actually showed an association between the use of Tylenol and autism, but that association disappeared when they applied controls of siblings who were not exposed to Tylenol during pregnancy. Sibling controls accounted for genetic and other environmental factors. Furthermore, no increasing dose response results were found, as would be expected with a causative agent. A Japanese study of more than 200,000 children with sibling controls also yielded the same conclusions.
Federal health officials selectively cite and misinterpret studies to support Kennedy’s agenda. It is worth noting that the American Psychiatric Association, the American College of Obstetricians and Gynecologists, the Society for Maternal-Fetal Medicine, the American Academy of Pediatrics, and others consider the judicious use of Tylenol safe during pregnancy.
Despite the rhetoric of the press conference and a safety warning that should be added to the label of Tylenol, the recommendation of the Federal Food and Drug Administration is that the lowest effective dose is used for the shortest possible duration. Good advice for most medicines used during pregnancy. Nothing new here.
Under pressure, Kennedy has since admitted that he doesn’t have enough evidence to support a causative link — yet.
Women should feel safe using Tylenol during pregnancy. It is one of the few options available to treat pain and fever. Consult your doctor for advice and cast a critical eye on anything Kennedy or Trump might give medical advice.
A former resident of South Bend, Dr. Richard Feldman is an Indianapolis family physician and is a past Indiana state health commissioner. Email him at richarddfeldman@gmail.com.
This article originally appeared on the South Bend Tribune: Getting beyond the confusion, misinformation about Tylenol | Opinion