On September 22, 2025, the U.S. Food and Drug Administration (FDA) announced it is initiating a label change for acetaminophen, commonly known as Tylenol, to reflect evidence suggesting a potential association between its use during pregnancy and increased risks of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in offspring.
The decision follows a review of studies, including a recent BMC Environmental Health analysis of 46 studies, which found a correlation but no established causation. The FDA emphasized that while some observational studies, such as the Nurses’ Health Study II and Boston Birth Cohort, indicate a possible link, others, including a 2024 Journal of the American Medical Association study, found no association in sibling-controlled analyses, suggesting confounding factors may explain earlier findings.
The agency is advising physicians to minimize acetaminophen use for low-grade fevers during pregnancy, citing the precautionary principle, while noting that it remains the safest over-the-counter option for treating fever and pain in pregnant women, as untreated fevers may pose risks like miscarriage or birth defects. FDA Commissioner Marty Makary clarified that the choice remains with parents and doctors, but the agency aims to raise awareness of potential risks.
This announcement has drawn criticism from major medical organizations, including the American College of Obstetricians and Gynecologists, which called the move “not backed by the full body of scientific evidence” and potentially harmful due to the lack of clear causal data. The World Health Organization and European Medicines Agency have also urged caution, noting inconsistent evidence and the absence of a proven link. The debate underscores the complexity of autism’s causes and the need for further research to clarify acetaminophen’s role, if any, in neurodevelopmental outcomes.
