The average menstruation is 4-6 days, for example, if the menstruation is 28 days, the fourth day of clean is about the 8th-10th day of the menstrual cycle, and the normal thickness is about 2-5㎜, and at this time, the endometrium is in the middle or late stage of proliferation.
At this time, the endometrium is in the middle or late stage of proliferation. After the end of menstruation, the thickness of endometrium is only about 1~2㎜, and then slowly under the action of hypothalamus-pituitary-adrenal axis, the follicles in the ovaries gradually develop and synthesize estrogen, which makes the epithelial cells on the surface of the endometrium appear as columns, the glands increase, the mesenchyme is slightly watery, and the blood vessels are more proliferative, and then gradually become thicker, and the normal thickness of the fourth day of a clean menstrual cycle is about 2~5㎜.
If ovarian dysfunction and insufficient estrogen secretion result in poor endometrial proliferation, the endometrium may be relatively thinner on the fourth day after menstruation, which may lead to ovulatory disorders such as abnormal uterine bleeding, etc. The diagnosis can be clarified by combining ultrasound, hormone examination and scraping, and the treatment can be carried out through the method of estrogen and progesterone sequencing.