Emergency contraception is a contraceptive remedy used by women to prevent the occurrence of unwanted pregnancy within the effective time after sexual intercourse without contraceptive measures (unprotected) or contraceptive failure (broken or slipped condom, missed pill, etc.), including oral emergency contraceptive pills or intrauterine device placement, in order to prevent unwanted pregnancy or reduce the occurrence of abortion, so emergency contraception is also called aftercare contraception. It is also called emergency contraception. For: 1. Contraceptive failure, including penile condom rupture, slippage; failure to achieve in vitro ejaculation; incorrect calculation of the safety period; omission of short-acting contraceptive pills; IUD detachment. 2, sexual life did not use any contraceptive measures. Methods: 1. IUD Put in within 5 days (120 hours) after unprotected sex, the efficiency is more than 95%. 2.Emergency contraceptive pill (1) Yutin (levonorgestrel tablets) is a more commonly used emergency contraceptive pill to avoid pregnancy by inhibiting follicle development, inhibiting or delaying ovulation, affecting endometrial development, and interfering with different aspects of implantation. It is used by taking the first tablet (0,75mg) within 72 hours after intercourse, and the second tablet (0,75mg) 12 hours later, for a total of two tablets. This product is an emergency contraceptive and cannot be taken as a regular contraceptive. (2) Mifepristone Mifepristone 10mg or 25mg can be taken within 5 days after unprotected sexual intercourse.