The thickness of the endometrium definitely affects pregnancy; if the endometrium is too thin, there is no way for a fertilized egg to bed, which can clinically lead to infertility. If the lining of the uterus is too thick, it also affects the fertilization of the egg, whether it is thin or thick. The thickness of the endometrium at the time of ovulation is around 9-12mm, which is conducive to the fertilization of the egg, and is clinically normal. If the lining is thin during ovulation, it is best to rule out thinning of the uterine lining due to estrogen deficiency or due to incomplete adhesions in the uterine cavity, and treat accordingly depending on the specific situation. If the endometrium is too thick, we should exclude the possibility of endometrial inflammation or endometrial pathology, and it is better to do diagnostic scraping, and the final pathological diagnosis will be based on the clinical treatment.