• Posted November 12, 2025

No Clear Link Between Acetaminophen And Autism Or ADHD, Major Reviews Find

There’s no clear evidence linking acetaminophen use during pregnancy with developmental issues like autism or ADHD, two major evidence reviews have concluded.

Any increased risk observed in dozens of studies tended to cancel out when researchers adjusted for other potential factors, or when they compared between siblings to validate their findings, both evidence reviews found.

“Existing evidence does not show a clear link between in utero exposure to (acetaminophen) and autism and ADHD in offspring,” concluded researchers in The BMJ.

These reviews follow an exhortation by President Donald Trump in September that women avoid using acetaminophen, sold over the counter as Tylenol, during pregnancy due to increased risk of autism.

“Tylenol during pregnancy can be associated with a very increased risk of autism,” Trump claimed, according to The Associated Press.

“I want to say it like it is, don’t take Tylenol,” Trump also said, encouraging women to “just fight like hell not to take it.”

His comments run counter to guidelines from medical societies like the American College of Obstetricians & Gynecologists (ACOG). It says, “Acetaminophen is well studied and proven to be safe for use in pregnancy, and is one of the only medicines available to pregnant women for pain relief and treatment of headaches and fevers."

For an extensive review published Monday in The BMJ, researchers analyzed data from 40 studies included in nine prior reviews looking at acetaminophen and developmental problems. 

Seven of the nine reviews warned against drawing a cause-and-effect link between acetaminophen and autism or ADHD, citing the chance that contributing factors like genetics hadn’t been fully taken into account.

Only one review included studies that appropriately adjusted for the potential effect of genetics or environmental factors. The observed link between acetaminophen and autism or ADHD disappeared when researchers accounted for those effects, the review found.

“Any apparent effect observed after in utero exposure to (acetaminophen) on autism and ADHD in childhood might be driven by familial genetic and environmental factors and unmeasured confounders,” concluded the review team led by Dr. Shakila Thangaratinam, dean of the Institute of Life Course and Medical Sciences at the University of Liverpool in the U.K.

The other review appeared in the Journal of the American Academy of Child & Adolescent Psychiatry, and evaluated results from 16 prior studies involving nearly 3 million children.

Again the results showed that any increased risk of autism or ADHD observed in the studies could be accounted for by other factors like genetics, according to the team led by Anick Bérard, a professor of pharmacy at the University of Montreal in Canada.

This was particularly clear in studies where siblings were compared, which is the considered the most reliable study design for assessing genetic risks, researchers said. Any observed risk disappeared when the studies compared siblings.

Dr. David Coghill, chair of developmental mental health at the University of Melbourne in Australia, reviewed the second study’s findings.

“This is a landmark study that highlights the importance of good science and strong methods,” he said in a news release.

“The findings of no association between acetaminophen use during pregnancy and the risk of autism and ADHD in the child are not unexpected,” Coghill continued. “These new findings support the position of professional organizations and regulatory bodies around the world that women should continue to use acetaminophen during pregnancy and do so without fear.”

The fact, he added, "that they contradict the recent announcements by the U.S. government must be acknowledged and acted on.”

More information

The American College of Obstetricians & Gynecologists has more on acetaminophen in pregnancy.

SOURCES: The BMJ, study and news release, Nov. 10, 2025; American Academy of Child & Adolescent Psychiatry, study and news release, Nov. 6, 2025