What is the pregnancy category of Nitroglycerin?

The pregnancy category of Nitroglycerin is actually Category C. This classification indicates that while animal reproduction studies have shown an adverse effect on the fetus, there are no adequate and well-controlled studies in pregnant women. Nitroglycerin can cross the placenta and has been associated with potential risks; however, it may still be used in pregnancy if the potential benefit justifies the potential risk to the fetus.

The other categories do not apply in this case. Category A is for drugs that have been shown to have no risk to the fetus in the first trimester, and existing data in later trimesters does not indicate risk. Category B indicates that animal studies have not demonstrated a risk to the fetus, but there are no well-controlled studies in pregnant women. The category "None" does not pertain to the classification system used for assessing the teratogenic risk of drugs during pregnancy.

Thus, Nitroglycerin is classified as Category C due to its potential effects and the consideration of its risks versus benefits in pregnant patients.