Читать книгу Zita West’s Guide to Getting Pregnant - Zita WEST, Zita West - Страница 51

Progesterone is the hormone that keeps the endometrium, or lining of the womb, in place. It keeps it thick and ensures a continuing blood supply – just in case a fertilized egg needs to implant. If implantation does occur, the production of progesterone from the ovary continues until around 12 weeks, when the placenta is sufficiently developed to take over production for the rest of the pregnancy. If there is no implantation, the body responds by reducing its levels of progesterone, and a period occurs – when the thick, blood-rich lining of the womb is discarded.