For expecting women, a strong link between acetaminophen and autism would be cause for alarm. But despite a recent flurry of alarmist headlines, the evidence for such an association is still lacking.

Pregnant women generally rely on acetaminophen, a painkiller commonly found in Tylenol, rather than potentially-risky ibuprofen to manage fevers and pain. But after a June study in the International Journal of Epidemiology turned up a link between acetaminophen use during pregnancy and the incidence of autism and ADHD in children, the media was quick to exaggerate the findings.

The biggest offender, of course, was the Daily Mail, which declared in its headline that “women who take paracetamol [acetaminophen] during pregnancy ‘risk having a child with autism or ADHD.’” The words in single-quotes do not appear in the study itself.

As the UK’s National Health Service (NHS) was quick to point out in response, the study “provides no evidence of a direct link to either condition.”
Here’s what the study of over 2,500 mother-child pairs in Spain actually found: Male children who had been exposed to the painkiller in utero experienced symptoms of autism and ADHD in a way that seemed “dependent on the frequency of exposure.” For female children, only the link between acetaminophen and attention-related symptoms could be confirmed.
While that may sound concerning, the study is riddled with methodological holes that should cast doubt on strong claims of a causative relationship between acetaminophen use during pregnancy and autism or ADHD.
For one, the authors could not completely rule out the possibility that the underlying medical conditions which prompt pregnant women to use acetaminophen could account for some of the symptoms experienced by their children down the line.

“Since ADHD and ASC [autism spectrum condition] have been associated with maternal infection and inflammation, despite adjustment for reported maternal chronic illness, urinary tract infection and fever, residual confounding by indication could still be a limitation,” the authors noted.

In layman’s terms: illness during pregnancy, not painkiller use, could partially account for their findings.

Read the whole story at The Daily Beast