President Donald Trump insisted on Monday that pregnant women should “tough it out” and avoid Tylenol due to an unproven link to autism, and also urged major changes to the standard vaccines administered to babies.

Medical groups have long cited acetaminophen, or paracetamol—the primary ingredient in Tylenol—as among the safest painkillers to take during pregnancy.

WHO spokesman Tarik Jasarevic acknowledged that some observational studies—which are based purely on observations and do not include control or treatment groups—had “suggested a possible association between prenatal exposure to acetaminophen or paracetamol and autism.”

But, he told reporters in Geneva, “the evidence remains inconsistent” with other studies finding “no such relationship”.

“If the link between acetaminophen and autism were strong, it would likely have been consistently observed across multiple studies,” he said, warning against “drawing casual conclusions about the role of acetaminophen in autism”.

‘No evidence’

European medical regulators, meanwhile, said their recommendations that pregnant women can use paracetamol for pain relief had not changed.

“Patient safety is our top priority. There is no evidence that taking paracetamol during pregnancy causes autism in children,” Alison Cave, safety chief at Britain’s Medicines and Healthcare Products Regulatory Agency, said in a statement.

Steffen Thirstrup, chief medical officer at the European Medicines Agency, agreed.

“Our advice is based on a rigorous assessment of the available scientific data, and we have found no evidence that taking paracetamol during pregnancy causes autism in children,” he said.

Vaccines were also on the rambling agenda of Trump’s press conference on Monday, when he repeated anti-vax movement talking points.

He sowed doubt over standard vaccines, including the MMR shot—which covers measles, mumps, and rubella—and implied he would end the common use of aluminium in vaccines, the safety of which has been widely studied.