Pregnancy after surgery for incomplete mediastinum uterus will not result in fetal arrest if it is not affected by infections, restricted space for fetal growth, etc. If it is affected again by factors affecting fetal development, fetal arrest will still occur. Incomplete mediastinum uterus affects the development of embryo mainly because of the lack of space in the uterus, the growth of the fetus does not have sufficient place, but we can not rule out infectious factors, fetal chromosomal abnormality, and other factors lead to the case of fetal arrest. If the space of the uterus is enlarged after the surgery, the factor of space limitation is lifted, and there is no stimulation from other unfavorable factors, fetal arrest will not occur. If after the surgery, the uterus is still affected by infection and other conditions, fetal arrest may still occur. It is recommended that women with incomplete mediastinum uterus who become pregnant after the surgery should pay attention to regular pregnancy checkups and seek timely medical advice on what to pay attention to during pregnancy to promote healthy development of the fetus.