(NEW YORK) — Taking acetaminophen, also known by the brand name Tylenol, during pregnancy had no effect on children developing autism, according to a study of over 1.5 million children in Denmark published this week.
The study was published in JAMA Pediatrics.
Researchers analyzed 1.5 million children born between 1997 and 2022. About 1.8% of those who were exposed to Tylenol during pregnancy developed autism compared to 3.0% of those who were not exposed to Tylenol.
A prior study out of Sweden looked at siblings, finding no causal link between autism and Tylenol exposure during pregnancy. There are genetic associations and environmental triggers that are likely involved, but neither Tylenol nor vaccines has been shown to be the cause of autism.
The new study out this week comes after President Donald Trump and his administration had previously urged pregnant mothers to avoid Tylenol, without substantive evidence for the claims.
“With Tylenol, don’t take it. Don’t take it,” Trump said during a press event at the White House in September. “If you can’t live, if your fever is so bad, you have to take one, because there’s no alternative to that.”
The FDA then initiated a process to update the safety label on acetaminophen to suggest that its use during pregnancy and autism were linked.
At the time, Kenvue, the maker of Tylenol, wrote in part of a statement, “We believe independent, sound science clearly shows that taking acetaminophen does not cause autism. We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers.”
At the time, medical organizations, like the American College of Obstetrician & Gynecologists, immediately pushed back, noting that Tylenol was one of the few options for pregnant women to treat pain and fever, which can be harmful when left untreated.
It is generally not recommended for pregnant women to take ibuprofen, Advil, during pregnancy due to the risk of complications.
Nevertheless, the claims made by the administration have led to confusion. A prior study found that Tylenol use in emergency departments dipped 16% immediately following the announcement by the administration.
ABC News reached out to Kenvue, the maker of Tylenol, for a statement but did not immediately hear back.
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