Donald Trump has urged pregnant women not to take acetaminophen, also known as Tylenol or paracetamol. He claimed it raises the chances of children being autistic.

But the US president has been condemned by experts from across the world, who fear he is deliberately fostering a narrative of distrust that could be dangerous for women.

Does paracetamol cause autism?

The short answer is: no. Genetics plays a major role in autism, but scientists are also investigating the potential role of environmental factors such as parental age, premature birth and prenatal exposure to drugs, environmental chemicals or infections.

“The idea that something that occurs during pregnancy may influence neurodevelopment isn’t a particularly new or crazy or outlandish idea,” said Renee Gardner, an associate professor of epidemiology at Sweden’s Karolinska Institute. “We know there’s a large heritable or familial influence, but environment interacts with genetic tendencies.”

Paracetamol has been widely used for pain relief since the 1950s and is recommended by the NHS as the first choice of painkiller if you are pregnant. In recent years, a number of studies have suggested that women who take paracetamol during pregnancy are very slightly more likely to have a child who is diagnosed with autism. But this does not prove that the link is causal and agencies such as the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) have stated there is no evidence that taking paracetamol during pregnancy causes autism in children.

The US Food and Drug Administration is changing the label on Tylenol to warn of a “possible association” between autism and taking the drug in pregnancy. It has also alerted physicians nationally. The agency makes clear that a causal relationship between Tylenol and autism has not been established. It also notes that it is the only drug approved to treat fever in pregnancy and high fever can be risky for babies in the womb.

But experts are concerned that Trump’s less measured instruction to “fight like hell not to take it” may be what ends up sticking in the minds of many patients.