White House links Tylenol in pregnancy to autism, prompting scientific debate

President Donald Trump said on Sept. 22 that acetaminophen, the active ingredient in Tylenol, used during pregnancy increases the risk of autism, a claim that runs counter to the guidance of leading obstetrics groups. Speaking at a White House briefing flanked by U.S. Health and Human Services Secretary Robert F. Kennedy Jr. and other federal officials, Trump urged pregnant women to avoid Tylenol unless they have an extremely high fever, arguing that there is no downside to not taking it and that patients should “fight like hell” not to use the drug. The announcement drew immediate pushback from the obstetrics community and highlighted a broader and ongoing debate about whether prenatal acetaminophen is linked to neurodevelopmental outcomes in children.

Medical experts and professional bodies quickly pushed back. The American College of Obstetricians and Gynecologists said there is no clear evidence linking acetaminophen use during pregnancy to autism or other fetal-development risks. ACOG noted that fever itself can pose risks during pregnancy, and that acetaminophen remains the only over-the-counter medication approved to treat fevers in pregnancy. The association cautioned that policy statements should be based on robust data and warned that oversimplified messages about a drug’s risks could affect the health of millions of people.

The scientific landscape surrounding prenatal acetaminophen use and neurodevelopment has been mixed for years. A review published in August in the journal BMC Environmental Health analyzed 46 studies and concluded there was an association between prenatal acetaminophen exposure and the incidence of neurodevelopmental disorders, including autism and attention-deficit/hyperactivity disorder (ADHD). Lead author Dr. Andrea Baccarelli, a senior investigator on the study, told TIME that he discussed the findings with Kennedy and NIH Director Dr. Jay Bhattacharya in recent weeks and that, given the review’s conclusions, caution about heavy or prolonged use of acetaminophen during pregnancy is warranted. The study also noted a potential conflict of interest because Baccarelli has served as an expert witness in a case involving potential links between prenatal acetaminophen use and neurodevelopmental disorders, a point acknowledged in the review.

Supporters of the review say it adds to a growing body of signals that require careful examination, while critics argue that the published literature largely suffers from methodological flaws. Dr. Nathaniel DeNicola, an obstetrician-gynecologist who advises ACOG on environmental health issues, said many of the studies linking acetaminophen to neurodevelopmental outcomes are based on designs that are unreliable. “The studies that have claimed an association were so deeply flawed that you can’t draw any conclusion,” he said. He noted that many investigations relied on mothers recalling acetaminophen use after the fact, sometimes years later, and did not adequately account for genetics—an important factor given the heritability of autism.

Higher-quality work that includes genetic considerations has tended to dim or eliminate the signal of a causal link. A 2024 study in JAMA examined electronic medical records from nearly 2.5 million Swedish children born between 1995 and 2019. In an initial analysis that did not account for genetics, researchers observed a small association between prenatal acetaminophen exposure and autism, ADHD, and intellectual disability. But when siblings were compared—exposing one child to the drug during pregnancy and not exposing another within the same family—the association disappeared. Brian Lee, a Drexel University epidemiology professor who led the study, said the within-family analysis suggests the initial link was likely confounded by genetic factors or related environmental influences. “What this tells us is that the [initial] association was most likely due to genetics,” he told TIME. He added that correlation does not establish causation, and that people with autism also tend to experience higher rates of pain conditions that prompt acetaminophen use.

During the White House briefing, FDA officials acknowledged the ongoing scientific debate and said the agency would issue a notice to physicians about potential risks associated with acetaminophen use during pregnancy. They also indicated the agency would pursue a safety-label change for the drug. Kennedy, meanwhile, framed autism as a “horrible, horrible crisis” that demands federal attention and noted that NIH and other agencies are actively investigating possible causes, including the broader topic of vaccines. Large-scale research over decades has found no link between vaccines and autism, but Kennedy reiterated that autism’s causes are multifactorial, involving genetics and environmental factors such as maternal health and exposure to pollutants.

Kenvue, the parent company of Tylenol’s manufacturer, has said the science does not support a causal link between acetaminophen use during pregnancy and autism. In a prior statement to the Wall Street Journal, the company said it has “continuously evaluated the science” and stands by the position that there is no causal relationship. The stock market reaction to the briefing reflected investor sensitivity to the health-policy implications of the discussion, with shares of Kenvue trading near all-time lows around Sept. 22, according to Barron’s.

Medical experts emphasize that fever during pregnancy itself can pose risks, including miscarriage, fetal malformations, and other complications, underscoring why acetaminophen remains the preferred OTC option for fever and pain in most obstetric guidelines when used at the lowest effective dose and for the shortest possible duration. Dr. Steven Fleischman, president of ACOG, cautioned that while clinicians will continue to review the evidence, the current body of research does not establish a causal link between prenatal acetaminophen exposure and autism and urged patients not to abandon a medication that helps manage fever in pregnancy when it is medically indicated. He also stressed the need for robust, well-designed studies to guide any changes in clinical practice.

In the near term, the FDA’s notice and planned labeling changes aim to improve risk communication for pregnant patients who rely on acetaminophen to manage fever or pain. The agency’s actions, together with ongoing investigations into autism’s multifactorial origins, reflect a broader effort to reconcile public health messaging with evolving science. For expectant families, medical guidance remains clear: consult with a clinician about the lowest effective dose, duration, and alternatives when appropriate, and avoid self-directed changes to medication regimens during pregnancy based on preliminary or nondefinitive findings.