A thick endometrium may affect pregnancy. Typically, from the end of menstruation, the endometrium will gradually grow and thicken from 0.5 millimeters to about 5 millimeters in response to hormones. If ovulation does not result in conception, the endometrium will continue to thicken, reaching about 10 millimeters by the time of premenstrual period. Then as the luteal function fails, hormone levels drop and the endometrium is triggered to shed, creating menstruation. If the lining of the uterus is too thick, it means that there is hyperplasia of the uterine lining, which may make it difficult for an already fertilized fertilized egg to latch on and develop, and therefore may affect pregnancy. If the examination finds that the endometrium is too thick, such as the endometrium before menstruation > 2cm, or even > 2.5cm, it means that the endometrium may have polyps or lesions, which may affect pregnancy at this time. If the endometrium is found to be too thick, it should be diagnosed under the guidance of a doctor and treated in a standardized way to avoid delaying the condition.