Using Tylenol to reduce fever during pregnancy is recommended because fever exposure carries significant risks to a developing fetus.

“Let's not forget Tylenol is also used to reduce fever. And for this purpose, current evidence would suggest that the scales clearly tip uh in favor of using Tylenol since exposure to fever itself carries a number of known risk factors to a developing fetus. So for for example, children born to mothers who experience fevers during pregnancy, especially during the first trimester, are at a significantly higher risk of certain birth defects than children um who weren't exposed to fever in in uterro. For example, various analyses have reported anywhere from 25 to 200% higher risk for cleft pallet or neural tube defects.”