In September of 2025, President Donald Trump and Health Secretary Robert F. Kennedy Jr. declared that women should avoid Tylenol during pregnancy due to a link between the drug and autism. At the time, the connection was not supplemented with scientific evidence. Now, researchers have followed up with a very thorough analysis stating otherwise.
A review, published on January 16, 2026, in the medical journal The Lancet Obstetrics, Gynaecology, & Women’s Health, found no link between pregnant women taking acetaminophen (the active ingredient in Tylenol) and their children having autism, ADHD, or intellectual disability.
“After this declaration, there were a lot of mothers who actually were scared to take [Tylenol] paracetamol,” said Dr. Francesco D’Antonio, one of the paper’s authors and a professor of fetal medicine at the University of Chieti in Italy. “The day after this declaration, actually, we had a massive increase in phone calls and emails from women.”
The main finding in the report is that acetaminophen is safe during pregnancy and remains the first line of treatment for women with a fever or pain. The Lancet referred to the paper as the “gold-standard evidence review,” a description that echoes language used by Kennedy when he said the National Institute of Health would deliver “unbiased, depoliticized, gold standard scientific research and academic freedom” in its investigation of autism causes.
Researchers who were not involved in the new paper are showing tremendous support for the findings.
“I don’t think there’s a better way to analyze the data than this Lancet paper does,” said David Mandell, a psychiatry professor at the University of Pennsylvania.
A team of seven researchers from the U.K., Italy, and Sweden reviewed existing research to determine whether using Tylenol (acetaminophen) during pregnancy is linked to neurodevelopmental disorders. They first narrowed thousands of studies down to 43 by excluding those that lacked proper comparison groups, relied on self-reported data, or did not account for mothers’ health histories and medication use. Only studies based on medical records or clinician-reviewed questionnaires were included.
The researchers then evaluated the quality of these studies, removing those with weak designs or unclear outcomes. Finally, they closely examined the two strongest studies, which compared siblings exposed to Tylenol in the womb with unexposed siblings, effectively controlling for genetic and environmental factors.
All three analytical approaches reached the same conclusion: There is no evidence that Tylenol use during pregnancy is associated with autism, ADHD, or intellectual disability.
Some people are not as impressed by the findings. Health and Human Services (HHS) officials criticized the new analysis, saying it does not settle the question of whether Tylenol use during pregnancy is linked to autism. An HHS spokesperson argued that the researchers biased their results by excluding certain evidence and designing the study in a way that favored finding no association. The department pointed to concerns raised by some experts, including Dr. Andrea Baccarelli of Harvard, whose 2023 review reported an association between prenatal Tylenol use and autism and was cited by the Trump administration as evidence of risk.
However, researchers involved in the new analysis pushed back, saying Baccarelli’s review and similar smaller studies likely failed to adequately control for confounding factors. They also noted that Baccarelli’s review examined far fewer studies than the new analysis, with one expert calling the earlier search process “sloppy.”
Autism researchers say the issue is settled. Alycia Halladay of the Autism Science Foundation stated that there has never been a link between acetaminophen and autism and that continuing to debate it only misleads families and unfairly places blame on mothers, diverting attention from researching the real causes of autism.
