why are they saying tylenol causes autism

They are saying that Tylenol (acetaminophen) causes autism mainly because of recent claims and some studies indicating a potential association between prenatal use of acetaminophen and an increased risk of autism and other neurodevelopmental disorders like ADHD. President Donald Trump and his administration have highlighted concerns about acetaminophen use during pregnancy, labeling it a "very big factor" in autism risk, and have issued new health guidance to caution its use by pregnant women. However, the scientific consensus remains unresolved and cautious. Many experts and large studies emphasize that the evidence only shows an association or correlation, not a proven causal relationship. Some studies comparing siblings and adjusting for genetics found no causal link. Medical organizations, including the Autism Science Foundation and the American Academy of Pediatrics, state that current data do not definitively support a causal connection between Tylenol and autism. They recommend careful and limited use of acetaminophen during pregnancy, pending further research. In summary, the claims stem from emerging but inconclusive research suggesting a possible link, amplified by political statements, but there is no definitive scientific proof that Tylenol causes autism.