Gestational trophoblastic disease (GTD) is a group of conditions that involve growth of tumors in the uterus. The cells that form these tumors are called trophoblasts, and form from the tissue that usually would become the placenta (the organ that connects the fetus to the mother for oxygen and nutrients) during pregnancy. While a woman with GTD may be initially diagnosed as being pregnant, the cells that would develop into a fetus do not develop normally, and therefore the pregnancy is not viable. GTD is detected early in pregnancy when symptoms include vaginal bleeding, very high levels of a specific hormone, or an abnormal ultrasound which tells the physician that something is wrong with the pregnancy. There are different types of GTD, but all are curable by either surgery, radiation therapy or chemotherapy. A physician will know which treatment option is best depending on the patient.