What characterizes Category X pregnancy drugs?

Category X pregnancy drugs are characterized by possessing a high risk and should never be used by pregnant women. This classification indicates that studies in animals or humans have demonstrated fetal abnormalities, and the risks involved in using the drug in pregnant individuals clearly outweigh any potential benefits. The designation emphasizes the severity of the risks that the drug poses, making it crucial for healthcare providers to avoid prescribing these medications when a woman is pregnant or may become pregnant. This designation is pivotal in guiding clinical decision-making to ensure the safety of both the mother and the developing fetus.

In contrast, the other options do not represent the characteristics of Category X drugs accurately. For instance, medications classified as harmless would fall into a different category, reflecting a lack of risk to pregnant women. Similarly, drugs that can be approved only under special circumstances would not be outrightly prohibited like Category X medications, and those that discourage use based on animal studies do not necessarily meet the high-risk criteria specified for this category.