Thyroid cancer can affect pregnancy because the thyroid gland is an endocrine organ and thyroid cancer can affect the level of many hormones in the body, which can affect the normal development of the fetus. In addition, thyroid cancer patients can be treated with surgery, iodine 131, chemotherapy, targeted therapy, immunotherapy, radiotherapy, all of which have side effects on the human body and will affect the normal development of the fetus. To sum up, thyroid cancer can affect pregnancy. However, if it is an early stage of thyroid cancer and hormone levels return to the normal range after radical surgery, pregnancy can be considered.