Thickening of the endometrium can affect pregnancy, mainly by affecting the fertilized egg’s implantation. After the sperm and egg combine in normal fertilization, the fertilized egg will bed and develop in the endometrium. When the endometrium is too thick, it will lead to obstruction of blood circulation in the endometrium, affecting the process of bedding and development of the fertilized egg, thus affecting pregnancy. Certain endometrial pathologies such as endometrial hyperplasia and endometrial polyps will thicken the endometrium and affect the fertilization of the egg. Ovarian and endocrine function may lead to abnormal thickening of the endometrium, which is often accompanied by impaired ovulation, thus affecting the fertilization of the egg. If endometrial thickening is diagnosed, early treatment is recommended to minimize the adverse effects of the disease.