The main purpose of ligation is to ligate both fallopian tubes, which are the tubes connecting the uterus and the ovaries and are the pathway for the sperm and egg to meet and for the fertilized egg to enter the woman’s uterine cavity and be laid. If the fallopian tubes are ligated and cut off, there is no way for the sperm and egg to meet, so the effect of contraception is achieved. Under normal circumstances, sperm enter the uterine cavity through the vagina and cervix of the woman after male ejaculation, and under the action of peristalsis of the uterine muscles, sperm wander into the fallopian tubes of the patient. At the same time, the umbilical end of the fallopian tube picks up the egg into the fallopian tube of the patient, so that the sperm and egg can meet to form a fertilized egg. After fertilization, the egg slowly enters the uterine cavity and implants itself under the peristaltic movement of the fallopian tube and cilia, thus completing the process of pregnancy. Therefore, if the fallopian tubes are severed, it is impossible for the patient to get pregnant again.