What the Research Shows About Tylenol (Acetaminophen) and Pregnancy

Debate has grown about whether taking acetaminophen (often called Tylenol) during pregnancy affects a child's development. Research over recent years has given mixed results, and scientists have used different methods that make comparison hard. Although some studies have found an association, none has proved a direct cause and effect.

A large sibling study in Sweden that included more than two million births used sibling comparisons and found no increased risk when siblings were compared. A separate review examined 46 studies and reported that many showed a possible link, while others did not. These differences are likely due to confounding factors such as infections, fever, or family background that are hard to fully measure.

Medical groups continue to recommend acetaminophen as the first-line treatment for pain and fever during pregnancy, but they advise using the lowest effective dose and seeking medical advice if you are unsure. Researchers call for more high-quality studies to clarify the issue. While the evidence is unsettled, clinicians must weigh the harms of untreated maternal fever as well as the possible medication risks.