Despite breast cancer diagnosis and treatment, women of childbearing age often desire a pregnancy. Since the average age of women giving birth for the first time is increasing, many young patients diagnosed with breast cancer have not started or completed their family planning. Thus, gynecologists and oncologists are confronted more often with the question of childbearing after breast cancer. Current data from retrospective trials do not suggest an increased risk of a recurrence or progress of the disease associated with pregnancy after stage-adjusted treatment. Also, the risk of fetal malformations and damage to the fetus after chemotherapy and/or hormone therapy seems similar to that in the general population. Women who receive chemotherapy are advised to wait at least 6 months before they attempt to conceive. The question whether to become pregnant must be discussed individually with the patient, based on tumor characteristics, stage of the disease and patient's wishes.