What is the pathogenesis of anovulatory functional uterine bleeding?

Xiaolan is about to graduate from high school this year and will soon face the college entrance examination. This is a major event in life, but for some reason, perhaps due to excessive tension and fatigue, Xiaolan's menstruation has begun to become abnormal in recent months. The frequency of menstruation has become more and more frequent, and the amount of bleeding has also increased. This is like adding insult to injury for Xiaolan, who is already anxious and nervous. Finally, one day she suddenly fainted in class. The next day, her mother rushed to the hospital for examination, and the result was a diagnosis of anovulatory functional uterine bleeding. The doctor told her parents to take good treatment for Xiaolan to avoid infertility and affect her future marriage life.

Anovulatory dysfunctional uterine bleeding mainly occurs in women during adolescence and menopause. The pathogenesis of the two is not exactly the same, and the main manifestations are:

(1) During puberty, the regulatory functions of the hypothalamus and pituitary gland are not mature, and stable cyclical regulation has not been established between them and the ovaries. In particular, there is a defect in the positive feedback effect of estrogen. During this period, the pituitary gland secretes FSH at a continuously low level, and there is no LH peak. Therefore, although there are batches of follicles growing, there is no ovulation. When the follicles develop to a certain extent, they undergo degeneration and form atretic follicles.

(2) During the menopausal transition period, due to the decline of ovarian function, the follicles are almost exhausted, especially the remaining follicles are less responsive to pituitary gonadotropins, estrogen secretion decreases sharply, and the negative feedback to the pituitary becomes weak. As a result, the gonadotropin level increases, but the ovulation peak cannot be formed, eventually leading to anovulatory functional uterine bleeding.