Breast cancer diagnosed during pregnancy is a challenging situation for the patient and her medical team. As women are delaying childbirth, the incidence is expected to increase. Most of the data surrounding the diagnosis and treatment of cancer during pregnancy is in case reports and small cohort studies. However, the data continues to expand regarding the safety of systemic treatments during the second and third trimesters for both the mother and the fetus. In this article, the use of diagnostic imaging, procedures, surgery and chemotherapy are reviewed as well as prognosis and future pregnancies after the treatment for breast cancer.