Pregnancy during chemotherapy for breast cancer usually requires termination of the pregnancy. Chemotherapy is short for chemical drug treatment, which kills cancer cells through the use of chemotherapeutic drugs to achieve the therapeutic purpose. Chemotherapy is one of the most effective means of cancer treatment, and it is one of the three major means of cancer treatment together with surgery and radiotherapy. Because chemotherapy requires a lot of medicines, the patient’s body is weakened during chemotherapy, the bone marrow hematopoietic function is inhibited, and the chemotherapy drugs are toxic and have greater side effects. The chemotherapy drugs are toxic and have big side effects. Pregnancy will lead to deformities and other physiological defects of the child, and usually it is necessary to give up the pregnancy in this situation, or it is recommended to actively treat the disease first. During chemotherapy for breast cancer, patients should pay attention to rest, increase nutrition, maintain a good state of mind, and actively cooperate with the doctor’s treatment.