Which of the following substances is NOT considered a teratogen?

Ciprofloxacin (Cipro) is not considered a teratogen, particularly in the context of significant risks during pregnancy. Teratogens are substances that can cause malformations or developmental issues in a fetus when exposure occurs during pregnancy. In contrast, Cipro is classified as a category C medication; while animal studies have shown adverse effects on the fetus, there are insufficient well-controlled studies in humans to affirm its teratogenic potential. This classification indicates that it should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

In comparison, alcohol is widely recognized as a teratogen associated with fetal alcohol spectrum disorders, leading to various developmental problems. Cigarettes also pose risks, including low birth weight, preterm birth, and developmental disorders. Accutane, a powerful retinoid used for severe acne, is well-documented for its high risk of causing severe fetal malformations if taken during pregnancy, resulting in stringent regulations regarding its use among women of childbearing age. Therefore, recognizing Cipro's lower risk profile in this context clarifies why it is not categorized as a teratogen.