Anovulatory Cycle - Estrogen Breakthrough Bleeding

Estrogen Breakthrough Bleeding

Normal menstrual bleeding in the ovulatory cycle is a result of a decline in progesterone due to the demise of the corpus luteum. It is thus a progesterone withdrawal bleeding. As there is no progesterone in the anovulatory cycle, bleeding is caused by the inability of estrogen - that needs to be present to stimulate the endometrium in the first place - to support a growing endometrium. Anovulatory bleeding is hence termed estrogen breakthrough bleeding.