Multiple studies have found no link between prenatal use of Tylenol, also known as acetaminophen, and the risk of autism or ADHD in children. The research, which includes a 20-year sibling-matched study, suggests that taking Tylenol during pregnancy does not increase the risk of these conditions. The findings are consistent across several studies, providing evidence that prenatal Tylenol use is not associated with a higher risk of autism or ADHD.