The most thorough analysis of the available data was released on Monday. Despite Donald Trump’s frequent assertions to the contrary, there is no conclusive evidence linking pregnant women who take the common analgesic paracetamol to autism in their offspring.

The US president infuriated the medical community in September by asserting that acetaminophen, another name for paracetamol, was linked to an increased incidence of autism.

Health researchers warned that Trump’s advice to pregnant women to “tough it out” instead of using paracetamol could scare them away from their safest option for treating pain and run the risk of further stigmatizing persons with autism.

The World Health Organization emphasized that there is no robust evidence connecting autism to paracetamol, the primary component of widely used medicines like Tylenol and Panadol.

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 UK-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.

A “historical and ongoing underinvestment in women’s health research” was noted in the overarching review, which recommended for improved research.

Research from multiple countries including those involving thiomersal or aluminum, has consistently refuted reports of a connection.

The observed association between paracetamol exposure and childhood autism and ADHD risk in both of these studies either vanished or decreased following correction, indicating that these factors account for a large portion of the reported risk, according to the researchers.