Top Universities and FDA Address Tylenol’s Autism Link in Pregnancy

Concerns regarding the potential link between acetaminophen, commonly known as Tylenol, and autism have prompted responses from leading universities and the Food and Drug Administration (FDA). The debate intensified following comments made by U.S. President Donald Trump and Robert F. Kennedy Jr., Secretary of Health and Human Services, who issued a warning to clinicians in mid-September 2025, advising against recommending the use of acetaminophen for pregnant women due to alleged associations with autism.

Dr. Zeyan Liew, an Associate Professor at the Yale School of Public Health, has dedicated years to researching neurodevelopmental disorders. He emphasized that there is “no proven causal relationship between acetaminophen use and autism.” While several large observational studies have suggested a correlation between frequent or prolonged use of acetaminophen during pregnancy and increased rates of neurodevelopmental disorders in children, experts caution that these findings are not definitive. Other factors, including genetic predisposition and underlying health conditions, may also contribute to the development of autism.

Research Highlights and Recommendations

A recent study published in the journal BMC Environmental Health by researchers from Harvard University, led by Dean Andrea Baccarelli, analyzed data from 46 previous studies worldwide. The research suggested that while it may be prudent to limit acetaminophen use, the medication is vital for managing pain and fever during pregnancy, conditions that can also pose risks to the developing fetus. The study noted that high fever can increase the likelihood of neural tube defects and preterm birth, leading the authors to recommend judicious use of acetaminophen. They advised expecting mothers to use the lowest effective dose for the shortest duration, ideally under medical supervision.

In late September, the FDA announced plans to send a letter to clinicians urging caution regarding acetaminophen use during pregnancy. Baccarelli discussed his findings with Secretary Kennedy before the announcement, highlighting evidence of a potential association between prenatal acetaminophen exposure and neurodevelopmental disorders. He noted that the association is strongest when acetaminophen is used for four weeks or longer.

FDA Commissioner Marty Makary stated, “The FDA is taking action to make parents and doctors aware of a considerable body of evidence about potential risks associated with acetaminophen.” He acknowledged that, despite this evidence, the ultimate decision rests with parents. He emphasized the importance of a precautionary approach, suggesting that many may choose to avoid acetaminophen during pregnancy, particularly for low-grade fevers that may not necessitate treatment.

Evidence from cohort studies, including the Nurses’ Health Study II and the Boston Birth Cohort, also points to a correlation between acetaminophen use during pregnancy and diagnoses of conditions like autism and ADHD. Some studies indicate that the risk could be more pronounced with chronic use throughout the pregnancy.

Industry Response and Expert Opinions

In response to the growing concerns, Kenvue, the manufacturer of Tylenol, stated, “Science clearly shows that taking acetaminophen does not cause autism.” Dr. Evan Schrader, an OB/GYN in Florida, expressed frustration over the dissemination of misinformation by influential figures. He emphasized that such claims could harm patients and undermine the efforts of dedicated medical professionals.

Dr. Schrader reaffirmed, “Tylenol has not ever been shown to have a causative effect on autism, and pregnant women and children should continue using this very safe medication when it’s indicated.” He urged individuals to consult their healthcare providers for personalized medical advice.

As the discourse surrounding acetaminophen continues, experts agree that more definitive research is necessary to clarify the potential risks involved. For now, both the FDA and the Centers for Disease Control and Prevention (CDC) maintain that acetaminophen remains the safest over-the-counter pain reliever for pregnant women.