The severe menstrual pain on the ninth day after transplantation is considered to be related to the stimulation of the uterus after the fertilized egg transplantation and the failure of the transplantation. 1. Uterine stimulation after transplantation: Transplantation is to transplant the fertilized egg directly into the uterine cavity of a woman, and the uterine cavity will have a slight rejection reaction in the early stage, which may cause abdominal pain. Moreover, the uterus may be stimulated to contract after transplantation, which may also cause abdominal pain. 2. Transplantation failure: If the abdominal pain persists without relief, we should also be alert to the possibility of transplantation failure, in order to discharge the pregnancy tissue in the uterine cavity, the uterus will strongly contraction of abdominal pain and vaginal bleeding and other clinical manifestations. For women with severe menstrual cramps on the ninth day after transplantation, it is recommended that they go to the reproductive department of a regular hospital for a clear cause of the disease and then actively treated under the guidance of the doctor.