What is hCG and what does it do?

human chorionic gonadotropin (hCG) is a hormone which is closely associated with the early stages of pregnancy. It is produced by the blastocyst once it has implanted into the endometrium of the uterus. hCG works by maintaining the corpus luteum, which secretes several hormones from the ovary. The key one in this case is progesterone, which maintains the endometrial lining of the uterus which is the site of implantation and supports blastocyst development.If the corpus luteum was not maintained by hCG, it would degenerate and stop producing progesterone and other hormones which, would trigger menstruation. The production of hCG therefore prevents menstruation, assuring that the endometrial lining and the blastocyst are not discarded. hCG continues this role until around two months into pregnancy, where the placenta takes over the production of progesterone.