The radiation emitted during chemotherapy would fall into which category of teratogen?

• A. Category D
• B. Category A
• C. Category B
• D. Category X

Answer: (A)

Teratogens are classified from A to X based on evidence of fetal risk. Category X means there is clear fetal harm and no benefit to justify exposure, so it is contraindicated during pregnancy. Radiation from cancer treatment is a well-established fetal hazard, with dose- and timing-dependent risks like birth defects or growth issues. Therefore, it belongs in Category X, not in Category A. Category A would imply no demonstrated risk, which isn’t true for radiation exposure in pregnancy.