The thickness of the endometrium is between 0.1 and 1.2 cm for women of childbearing age. Women get menstruation because the endometrium will shed and bleed when it reaches a certain thickness, which is also the period of menstruation. If the endometrium is 0.9cm, menstruation will occur in about a week. If the menstruation is delayed, the possibility of pregnancy cannot be ruled out in case of sexual intercourse, and a pregnancy test is recommended because women do not get their period once they are pregnant. If a woman has an endometrium of 0.9 cm and has a history of irregular menstruation or irregular bleeding even after a clean period, it is recommended to go to the hospital for a prompt examination. However, for menopausal women, if the endometrial thickness of 0.9cm is abnormal, it is recommended to go to the hospital promptly for examination and endometrial scraping under the guidance of a doctor to exclude the corresponding pathology.