Which drug category is contraindicated during pregnancy due to high teratogenicity?

The correct answer is Category X drugs, which are specifically classified as contraindicated during pregnancy due to their high teratogenicity and potential to cause significant harm to the developing fetus. This category includes medications that have been shown to cause fetal abnormalities and adverse outcomes in human studies, making their use in pregnant individuals absolutely contraindicated.

Category X drugs are recognized for their strong evidence linking drug exposure to serious fetal risks, often supported by clinical studies demonstrating such outcomes. This classification serves as a vital warning for healthcare providers, guiding them to avoid prescribing these medications to pregnant patients and to consider alternative treatments that carry less risk.

In contrast, Category A drugs are deemed safe for use in pregnancy based on well-controlled studies in pregnant women demonstrating no risk to the fetus. Category B drugs are generally considered safe as well, although animal studies may show some risks, and there are no adequate studies in pregnant women. Category C drugs may have some potential risks, and while they may be prescribed when no alternatives are available, they are not without concern. In essence, Category X represents the highest level of caution and contraindication for drug use during pregnancy.