There are three ways to prevent a woman from getting pregnant: first, by blocking the sperm from entering the woman’s body, either through in vitro ejaculation or the use of condoms, so that the sperm cannot enter the woman’s vagina and she cannot get pregnant. Second, to prevent the sperm from meeting the egg, the patient can use drugs that inhibit ovulation, such as birth control pills, or she can choose to use a female tubal ligation to block the passage for the sperm to meet the egg to achieve the effect of contraception. Third, contraception can be achieved by disrupting the fertilization of the egg. The IUD is placed in the uterine cavity to disrupt the implantation of the fertilized egg in the uterine cavity, so it can also achieve the effect of contraception.