Some chemotherapy drugs can affect fertility or lead to permanent infertility in both men and women. However, this is not true for all drugs, and therefore, pregnancy may be possible while chemotherapy is ongoing. Since chemotherapy drugs carry a significant risk of causing severe congenital anomalies in the fetus, effective birth control methods must be used throughout the treatment period. As the suitability of some methods, such as oral contraceptives and intrauterine devices (IUDs), may be debatable, alternative and safe methods recommended by the physician should be preferred. It is of great importance for female patients not to neglect their regular gynecological check-ups during and after chemotherapy. Furthermore, mothers diagnosed with cancer post-delivery and undergoing chemotherapy are advised not to breastfeed their babies due to the risk of drugs passing into breast milk.