But the study’s authors cautioned that the finding did not mean that acetaminophen was causing autism: The women who took acetaminophen during pregnancy may also have differed in important ways from the women who did not.

“We cannot answer the question about causation — that is very important to clarify,” said Dr. Diddier Prada, an epidemiologist at Mt. Sinai who conducted the study.

Debate Flares Over an Unproven Link Between Tylenol and Autism (New York Times)