Patients who are ready for IVF should have a physical examination after the menstruation of the previous menstrual cycle and prepare three certificates (marriage certificate, ID card and fertility certificate). On the 2nd or 3rd day of the current menstrual cycle, the woman will undergo ultrasound and sex hormone examination, and then the corresponding ovulation protocol will be formulated according to the examination results. It is one of the most commonly used regimens for ovulation promotion. The gonadotropin-releasing hormone (GnRHa) is injected from the luteal phase before the treatment cycle or on the second day of the treatment cycle, and the gonadotropin preparation HMG or FSH is added for ovulation promotion from the 14th to the 21st day after the CnRHa administration, until the HCG injection. 2. Short regimen: The short regimen requires a shorter period of time, about 10-15 days before and after. It starts with CnRHa on the 2nd or 3rd day of the menstrual cycle, while gonadotropin HMG or FSH is given until HCG is injected. 3.Antagonist regimen: It takes about 10-15 days and starts with gonadotropin HMG or FSH on day 2 or 3 of the menstrual cycle and starts with gonadotropin-releasing hormone inhibitor (CnRH-A) when the follicle grows to about 14 mm until HCG is injected. 4.Low stimulation regimen: the time required takes about 10-15 days, starting with clomiphene or letrozole orally on day 2 or 3 of the menstrual cycle, and 5 days later giving concurrent gonadotropin HMG or FSH until HCG injection. 5. Natural cycle: It refers to a form of pregnancy assistance without the use of any ovulation-promoting drugs, where the follicles are removed when they grow to maturity, fertilized with sperm in vitro to form embryos and placed back into the uterine cavity. In the above protocols, the growth of follicles is monitored by ultrasound from the 5th day of gonadotropin use, and blood is drawn to determine the hormone level. 10,000 IU of HCG will be injected on the same day (usually at 9-10 pm) to promote egg maturation; 34-36 hours after HCG injection (morning of the 3rd day of HCG injection), the eggs will be retrieved.