Sen. Cassidy challenges Trump's Tylenol-autism claim, urges HHS to release data
Louisiana Republican says studies do not support the link between acetaminophen in pregnancy and autism and calls for transparency from HHS as Kennedy-era health debates continue.
Sen. Bill Cassidy, a Louisiana Republican and gastroenterologist who chairs the Senate health committee, challenged President Donald Trump’s assertion that acetaminophen use during pregnancy is linked to autism, and he called on the Health and Human Services Department to release any evidence it has on the subject. In remarks Monday, Trump said the Food and Drug Administration would be “strongly recommending that women limit Tylenol use during pregnancy unless medically necessary.”
Cassidy addressed the president’s words on X, writing that the preponderance of evidence shows that this is not the case and that the concern is women will be left with no options to manage pain in pregnancy. He noted that HHS, led by Robert F. Kennedy Jr., should release new data to support the claim. The Louisiana Republican’s comments followed Trump’s blunt instruction that pregnant women avoid Tylenol unless a doctor prescribes it, a stance that aligns with Kennedy’s broader skepticism of vaccines and some modern medical practices.
On a radio appearance Tuesday, Cassidy described what he called the strongest available study on Tylenol use during pregnancy and autism, arguing it does not show an association. He cited a large Swedish study involving about two million people that compared autistic individuals to siblings without autism and found no link between acetaminophen exposure and autism. “There is an article out of Sweden — two million people followed — and they looked at someone who had autism and they compared them to a sibling who did not have autism, and they found no association, effectively, between taking Tylenol or not,” Cassidy said, calling it the “highest quality” and “best controlled” study on the subject. He stressed that an association does not prove causation, a point often echoed by critics of causal claims in observational studies.
Cassidy said he has already heard from concerned patients, including a pregnant woman who told him, “Two men telling me not to take the only thing I can take when my back’s hurting and I’m pregnant.” He said that while many doctors will deem acetaminophen safe for most pregnancies when used as directed, the timing and context of pain relief matters, and experts warn that fever during pregnancy carries risks. The Society for Maternal-Fetal Medicine has said that untreated fevers during pregnancy can increase the risk of miscarriage, premature birth and birth defects, underscoring that there can be downsides to avoiding fever reducers when medically necessary.
Cassidy’s stance on Kennedy’s health policy positions has been nuanced. Earlier this year, he indicated hesitancy about advancing Kennedy’s nomination to a full Senate vote, citing concerns rooted in vaccine policy and the potential implications for public health. He ultimately supported the nomination along with most Republicans in a 14-13 vote. In recent weeks, he also criticized Kennedy for canceling a roughly $500 million investment in vaccine research, saying the cancellation wasted already invested funds.
The exchange highlights how health policy and science are entwined with political signaling in the current Congress. Cassidy’s defense of conventional interpretations of Tylenol safety during pregnancy and his call for transparency from HHS contrast with Trump’s promotional framing of the issue and Kennedy’s public health stance, illustrating a broader debate over how evidence is communicated to the public during pregnancy and how agencies should handle evolving scientific data.
