Overview

• At a Thursday cabinet meeting, Robert F. Kennedy Jr. claimed newborn circumcision is followed by roughly double the rate of later autism diagnoses and attributed this to post‑procedure acetaminophen.
• President Donald Trump echoed the message, urging pregnant women and parents not to use Tylenol for themselves or newborns.
• Kennedy pointed to two observational papers from 2013 and 2015, including a Danish study in the Journal of the Royal Society of Medicine that did not identify a cause for the reported association.
• Autism researchers, including Helen Tager-Flusberg, criticized the studies’ methods and noted they contain no data on medications given, preventing any test of the proposed Tylenol mechanism.
• Scientists cite recent evidence against the claim, including a 2024 JAMA study from Sweden finding no link between prenatal acetaminophen use and autism, and warn such assertions risk confusing families.