Which agents require caution in pregnancy due to fetal harm?

• A. Most cytotoxic agents; methotrexate is particularly teratogenic; strict contraception and pregnancy testing are necessary.
• B. None require caution.
• C. Only targeted therapies require caution.
• D. Pregnancy is safe during chemotherapy.

Answer: (A)

The important idea is that many cancer drugs used in chemotherapy can harm a developing fetus, so pregnancy planning and monitoring are essential for anyone of reproductive potential receiving these medicines. Most cytotoxic agents are teratogenic, meaning they can cause birth defects or fetal harm if exposure occurs during pregnancy. Methotrexate is a standout example of a highly teratogenic agent, linked to neural tube defects and other malformations, so it demands especially strict contraception and pregnancy testing before and during treatment. Because of these risks, pregnancy during chemotherapy is not considered safe, and if pregnancy occurs, management requires careful coordination between oncology and obstetrics.

The other statements are not accurate: assuming no risk at all is incorrect, since cytotoxic drugs can seriously affect a fetus; restricting caution only to targeted therapies ignores the well-documented teratogenic risk of many cytotoxic agents; and claiming pregnancy is safe during chemotherapy contradicts established safety guidelines.