The presence of residues in the uterine cavity can repeatedly irritate the uterus, causing vaginal bleeding and prolonged bleeding, which may cause heavy bleeding in severe cases, leading to anemia and shock in women. The repeated irritation of the endometrium by the residue may also cause endometritis, which may also have an effect on the function of the endometrium, leading to a decrease in menstrual flow. In severe cases, uterine adhesions may develop, which may affect later pregnancy. In addition, incomplete abortion combined with infection can easily cause gynecological diseases, such as pelvic inflammatory disease, which can cause pain and fever in the lower abdomen and may lead to adhesions in the fallopian tubes. If the miscarriage is not complete, the patient will need to undergo another operation to clear the uterus.