Trump says he’s found the cause of autism. Here’s what the research shows

Health Minister Mark Butler has asked Australian authorities for quick advice on the link between paracetamol use in pregnancy and autism, after the Trump administration moved to start changing safety labels for the commonly used pain relief drug.

US President Donald Trump said on Tuesday (Monday, US time) that the Food and Drug Administration would notify doctors that paracetamol “can be associated” with an increased risk of autism a day after he declared “I think we found an answer to autism.”

Trump said his administration was urging pregnant women to largely avoid paracetamol – one of the most commonly used medicines in the world, sold under brand names including Tylenol in the US and Panadol in Australia.

“So taking Tylenol is not good — I’ll say it — it’s not good. For this reason, they are strongly recommending that women limit Tylenol use during pregnancy unless medically necessary,” Trump said at a White House event alongside Robert F. Kennedy Jr, his health secretary.

Butler, the day before Trump’s announcement, said he had asked Australian authorities for “some very quick advice on this”. But the health minister urged pregnant women to seek medical advice if they were concerned about using paracetamol.

“Paracetamol is not just a pain killing medication, it’s an important treatment for fever which can also be dangerous as well if untreated while you’re pregnant. We would caution anyone, any pregnant woman, [against] taking action in response to media reports like this without taking some medical advice first,” Butler said at a press conference in Canberra on Monday.

“Obviously, this is a very recent report. We’ve only read it in the last couple of hours. This is a very widely used drug, as everyone knows, and we want to make sure that we look very closely at any announcement from the US.

“Our [Therapeutic Goods Administration] works very closely with the [Food and Drug Administration]… and I want to make sure that we have advice for pregnant women, in particular, very quickly.”

Women are typically told to take paracetamol rather than ibuprofen, which can be harmful to the baby, during pregnancy. The current Tylenol label recommends pregnant or breastfeeding women to speak with a health professional before use.

Evidence is not conclusive: Australian scientists

Trump earlier this year tasked officials, including Kennedy Jr, with investigating rising autism rates. There has been an uptick in autism diagnoses across the world over the past decade, including in Australia. In April, Kennedy said: “By September, we will know what has caused the autism epidemic and we’ll be able to eliminate those exposures.”

This week’s announcement was the latest example of how Kennedy and Trump have sought to upend health guidance and practices in their administration. While there have been numerous studies into the cause of autism – including potential links to paracetamol use in pregnancy – decades of scientific research have yet to identify just one cause for the condition.

The Washington Post this week reported that US officials had looked at research including an August report from medical network Mount Sinai and Harvard University. That reviewed 46 previous studies, and found that prenatal exposure to paracetamol may increase the risk of neurodevelopmental disorders, but didn’t find that it directly caused them.

Australian researchers emphasised that no causal relationship between paracetamol use in pregnancy and autism had been established. They said any decisions must also be weighed against the risk of untreated fever in pregnancy.

“Evidence is mixed,” said Associate Professor Kevin Yap, from La Trobe University.

“A recent review in the US has reported associations between prenatal paracetamol use and slightly higher rates of autism, but a large Swedish study using sibling comparisons had found no effect when family factors were controlled... The results of this study have to be taken with caution.”

Dr Hannah Kirk, a senior lecturer in the Turner institute for Brain and Mental Health at Monash University, said the reports had “understandably raised concern among expectant parents”.

“However, no study has shown that [paracetamol] causes autism. Some studies have reported an association between [paracetamol] use and autism, while others have not. Importantly, association does not mean causation,” she said.

Professor Andrew Whitehouse, who leads autism research at The Kids Research Institute Australia, agreed. “Autism is a complex condition influenced by many genetic and environmental factors,” he said.

“Any small associations in this area need to be weighed against the risk of untreated high fever in pregnancy for the woman and the developing baby.”

Dr Gideon Meyerowitz-Katz, a senior research fellow from the University of Wollongong, said there had only been a handful of large scientific studies into the effect of paracetamol in pregnancy.

“None of them are sufficient for us to make any firm conclusions about the risk that paracetamol may or may not have. The largest study, from Sweden, in my opinion quite strongly demonstrates the risk is not that much of a concern,” he said.

“This [latest] furore is based on a specific study, a systematic review, where the authors argued overall that the data was consistent with paracetamol being associated with autism… Certainly, there’s no strong evidence that in utero exposure to [paracetamol] causes autism.”

The Swedish study, published in 2024, analysed the records of 2.48 million births from 1995 through 2019. The researchers, who compared siblings to control for genetic and environmental factors, found no increased risk of autism when their mothers took paracetamol while pregnant.

With Bloomberg

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