There are several reasons for bleeding after transplantation in women: First, it may be due to problems with the coagulation system. The normal human body has a coagulation system and an anticoagulation system, and these two systems are in a dynamic balance in the normal human body. If the coagulation system in the body is low, such as a decrease in the content of coagulation factors or platelets, enzymes, and abnormal structural functions, it can lead to a decrease or loss of coagulation function, resulting in a relatively hyperactive anticoagulation system, which can lead to bleeding after transplantation and is the most important cause of bleeding after transplantation in women. Second, it may be caused by abnormal levels of hormones in the body. When a woman has a transplant, the hormone levels in her body will also change significantly, such as estrogen, sex hormones and progesterone, which play an indirect or direct role in the formation and destruction of red blood cells. If the amount of hormones is abnormal, it can lead to changes in vascular permeability, which may lead to extravasation or outflow of blood, resulting in post-transplant bleeding.