Progesterone
Progesterone is a steroid hormone released in the ovary. In women, it plays important roles in regulating the menstrual cycle and reproduction, by helping to prepare the body for pregnancy, and maintain the early stages of pregnancy. In men, progesterone is involved in the development of sperm, and is produced at a much lower level than in women. It can help diagnose a failing pregnancy, determine the cause of infertility, or diagnose the cause of abnormal uterine bleeding, as well as adrenal diseases such as congenital adrenal hyperplasia.