Mechanism of action of sex hormones in perimenopausal abnormal uterine bleeding

Abnormal uterine bleeding in perimenopausal women is mainly associated with uterine and uterine cavity abnormalities,impaired coagulation function and disturbances of the hypothalamus-pituitary-ovary axis.Sex hormones play different roles in all causes.Disturbances of their level,action duration,and proportion may lead to functional AUB,AUB caused by endometrial hyperplasia,AUB caused by sex hormone drugs.The bleeding patterns mainly include estrogen withdrawal bleeding,estrogen breakthrough bleeding,and progesterone breakthrough bleeding.