PARIS, France (AFP) — There is no clear link between pregnant women taking the common painkiller paracetamol and autism in their children, despite repeated claims otherwise by Donald Trump, according to the most comprehensive review of the existing evidence published Monday.

In September, the United States (US)  president sparked outrage among the medical community by claiming that paracetamol — also known as acetaminophen — was associated with higher rates of autism.

Trump urged pregnant women to “tough it out” rather than take paracetamol, comments which health researchers warned could scare women off their safest option to treat pain — and risked further stigmatising autistic people.

The World Health Organisation has emphasised that there is no robust evidence showing that paracetamol — which is the main ingredient in massively popular painkillers such as Tylenol and Panadol — causes autism.

On Monday, an “umbrella” review of all the scientific research yet conducted on the subject was published in the British medical journal BMJ.

“Existing evidence does not show a clear link between in utero exposure to paracetamol and autism and ADHD in offspring,” the United Kingdom-lead team of researchers wrote in the review.

There have been several previous studies which suggested a possible link between paracetamol and autism or attention deficit hyperactivity disorder (ADHD).

However the quality of those studies was “low to critically low”, the review said, partly because they did not take adequate steps to rule out potentially misleading factors such as whether autism runs in the family.

These controversial previous studies also could not establish exactly how paracetamol might cause autism.

The umbrella review called for better research, pointing out that there has been a “historical and ongoing underinvestment in women’s health research”.

– Confirmation –

Several researchers praised the new study.

Dimitrios Siassakos, professor in obstetrics and gynaecology at University College London, said the review “confirms what experts around the globe have been saying”.

“Autistic and neurodivergent people are more likely to experience chronic pain, and they are also much more likely to have neurodivergent children — but paracetamol doesn’t cause neurodivergence,” said Steven Kapp of the University of Portsmouth.

“As a researcher and autistic person with ADHD, I think we should not be trying to prevent neurodivergence anyway, but make life better for neurodivergent people,” he added.

Beyond paracetamol, Trump and his vaccine-sceptic Health Secretary Robert F. Kennedy Jr have repeatedly made unfounded claims about autism, including that there is an “epidemic” of cases.

However experts maintain that the recent increase in autism rates is due to improved, broadened diagnosis methods along with growing awareness.