A nurse is caring for a female client who has rheumatoid arthritis and a new prescription for methotrexate. The client tells the nurse she is planning a pregnancy. Which of the following instructions should the nurse give the client?

Choice A rationale Methotrexate is a potent teratogen (Pregnancy Category X), meaning it has demonstrated a definite risk of severe congenital anomalies and fetal death. It inhibits DNA synthesis. Therefore, it must be discontinued, typically 3 to 6 months prior to conception to allow for complete drug clearance. Choice B rationale Methotrexate is excreted into breast milk and can cause serious adverse reactions in a nursing infant, including immune suppression and potential growth delays due to its cytotoxic nature. Therefore, breastfeeding is generally contraindicated while taking this medication. Choice C rationale Due to its teratogenic effects, methotrexate is contraindicated and must be stopped completely prior to and throughout pregnancy, not merely reduced. Dosage reduction would still expose the fetus to a significant and unacceptable risk of birth defects. Choice D rationale There are no specific dietary modifications proven to mitigate the teratogenic risk of methotrexate during pregnancy; the only safe measure is complete cessation of the drug well in advance of conception. The primary concern is the drug's effect on rapidly dividing fetal cells.