There are two types of mediastinum, incomplete mediastinum and complete mediastinum. Incomplete mediastinum has a relatively minor effect on pregnancy, and the patient can feel nothing and experience no abnormalities throughout the pregnancy. If the mediastinum is longer and belongs to complete uterine mediastinum, women who are pregnant often experience miscarriage, preterm labor, breech delivery, premature rupture of membranes, placenta previa, and abnormal postpartum bleeding. Uterine longitudinal septum is the cause of incomplete cavitation during the development of the uterus, the original one uterine cavity has become two uterine cavities, the small space in the uterine cavity is easy to cause infertility, and if the pregnancy is prone to miscarriage and premature birth. This disease can be checked before pregnancy, ultrasound can be found, and hysteroscopy can be a clear diagnosis. Hysteroscopic hysterectomy can treat this disease. Some patients may not be able to detect the disease easily if they are not tested before pregnancy. If the pregnancy is asymptomatic, the patient can continue the pregnancy and strengthen the management of the pregnancy. If the uterine septum has caused the embryo to stop developing or miscarriage, it is recommended that the patient undergoes electrosurgery of the mediastinum prior to the next pregnancy to remove the mediastinum before the pregnancy is carried out, which will give the patient a higher chance of success.