Trump officials are expected to link the use of pain reliever Tylenol in pregnant women to autism, according to US media reports.
At an Oval Office event on Monday, the US president will reportedly advise pregnant women in the US to only take Tylenol, known as paracetamol elsewhere, to relieve high fevers.
At the Charlie Kirk memorial service on Sunday, Trump said he had an "amazing" announcement coming on autism, saying it was "out of control" but they might now have a reason why.
Some studies have shown a link between pregnant women taking Tylenol and autism, but these findings are inconsistent and do not prove the drug causes autism.
