The role of night shots is to make multiple eggs develop and mature and control the time of ovulation, to facilitate the success of egg retrieval, night shots are mainly for women using IVF to get more than one egg, the use of a treatment. The chorionic gonadotropin, chorionic gonadotropin’s role is to promote the development and maturation of follicles, to prevent the eggs from being discharged prematurely, about 36 hours after the night shot can be artificially retrieved, in the retrieval of eggs will be obtained from a number of eggs, select high-quality eggs and sperm combined with the cystic treatment for transplantation to the uterus, which is conducive to improving the success rate of IVF. Women are injected when the menstrual cycle is 14-15 days before the night injection, and the dose and time of the drug need to be strictly controlled, otherwise it will cause severe ovarian hyperstimulation syndrome, and there will be ascites, abdominal distension and other gastrointestinal discomforts occurring.