Alarm as Trump peddles unproven causes of autism

Medical groups have reacted with dismay as President Trump has linked childhood vaccinations and use of the painkiller acetaminophen in pregnancy to autism.

A long list of expert organisations – including the American College of Obstetricians and Gynaecologists (ACOG), the Society for Maternal-Foetal Medicine (SMFM), the Autism Science Foundation (ASF), and patient advocacy group Autism Speaks – have all said there is no strong evidence for the claims made by the Trump administration.

That also includes a suggestion that folate drug leucovorin could be a treatment for speech-related deficits associated with autism, despite scant evidence from a handful of studies.

Among the measures planned by the White House and Department of Health and Human Services (HHS) led by Robert F Kennedy Jr is an update to the label of leucovorin to make it "the first FDA-recognised therapeutic for children with cerebral folate deficiency and autistic symptoms."

GSK has said it will file for approval of its Wellcovorin brand of the drug in this indication, saying it is "collaborating with the FDA to request a label update for this medicine as quickly as possible."

The FDA, meanwhile, is also updating the label for acetaminophen (also known as paracetamol) products, including the well-known Tylenol brand made by Kenvue, "to reflect evidence suggesting that the use of acetaminophen by pregnant women may be associated with an increased risk of neurological conditions such as autism and ADHD in children."

In a press conference at the White House to announce the initiatives, Trump repeatedly told women not to use acetaminophen in pregnancy or give it to young children, also claiming that childhood vaccines should not be taken closely together or early in childhood – a theme that was apparent at the recent CDC vaccines advisory committee meeting.

In reference to vaccines, he said: "Don't let them pump your baby up with the largest pile of stuff you've ever seen in your life." He also made the startling claim that Cuba "has virtually no autism" because they "don’t have Tylenol."

Kennedy said, meanwhile, that the FDA is "responding to clinical and laboratory studies that suggest a potential association between acetaminophen used during pregnancy and adverse neurodevelopmental outcomes."

Experts said the studies cited by Kennedy were selective, not scientifically rigorous, and do not support the claim either that acetaminophen can cause autism or that leucovorin is a treatment.

"Suggestions that acetaminophen use in pregnancy causes autism are not only highly concerning to clinicians, but also irresponsible when considering the harmful and confusing message they send to pregnant patients, including those who may need to rely on this beneficial medicine during pregnancy,” said Steven Fleischman, president of the ACOG.

The SMFM chimed in by saying that it "stands behind our recommendation that acetaminophen use during pregnancy has not been shown to cause or increase the risk of autism or other neurobehavioural problems in children" and is "an appropriate medication to treat pain and fever during pregnancy."

That view was echoed by Prof Claire Anderson, president of the Royal Pharmaceutical Society (RPS) in the UK, who said: "A large study conducted in 2024 found no evidence of a link between paracetamol use in pregnancy and an increased risk of autism in children. This research, which followed over 2.4 million children, provides reassurance for expectant parents that paracetamol remains a safe option for managing pain or fever during pregnancy when used as recommended."

On the vaccines side, the Partnership to Fight Infectious Disease (PFID) called the assertions made by the Trump administration "harmful and inaccurate," adding: "The science is clear: vaccines do not cause autism. Decades of rigorous, peer-reviewed research involving millions of children around the world have found no link between vaccination and autism spectrum disorder. Suggesting otherwise only spreads confusion, wastes resources, and undermines trust in tools that keep Americans healthy."

The ASF succinctly addressed the elephant in the room in all of this – a lack of any evidence for introducing the changes.

"We are unsure why this announcement came today and how the conclusions were drawn,” said Alison Singer, the organisation's president. “No new data or scientific studies were presented or shared. No new studies have been published in the literature. No new presentations on this topic were made at scientific or medical conferences. Instead, President Trump talked about what he thinks and feels without offering scientific evidence."