Review of 43 studies finds no link between prenatal acetaminophen and autism

A scientific review of 43 studies found no evidence that acetaminophen use during pregnancy increases the risk of autism or other neurodevelopmental disorders, the report’s lead author said. The review, led by Dr. Asma Khalil of St. George’s Hospital, University of London, was published on Friday in the British medical journal The Lancet.

The authors examined more than three dozen studies and concluded that they found "no clinically important increase in the risk of autism, A.D.H.D. or intellectual disability," Dr. Khalil said at a news briefing. She said acetaminophen, the active ingredient in Tylenol, remains "the first-line treatment that we would recommend if the pregnant women have pain or fever in pregnancy." Previous research has produced conflicting results.

A scientific review published last August by researchers at Harvard and the Icahn School of Medicine at Mount Sinai concluded there was evidence for a link and was cited by Mr. Trump’s health advisers in September, and President Trump later urged pregnant women not to take Tylenol.

The new review excluded studies that did not account for potential confounding factors such as infections and fevers, and it gave more weight to sibling-comparison studies that account for shared genetics and family environment; a large 2024 Swedish study found an initial association that disappeared in a sibling analysis.

Key Topics

Health, Acetaminophen, Autism, Tylenol, Asma Khalil, The Lancet