Long protocol: The most commonly used ovulation promotion protocol. Generally, from the 20th day of menstruation, the mid-luteal phase after ovulation is determined according to ultrasound and hormone measurement. When the mid-luteal phase is determined, descending drugs are injected first, and gonadotropin is added 14 days later for follicle development, which takes about 10-15 days. Short regimen: Starting on day 2 of the menstrual cycle with descending drugs, followed by gonadotropin injections 2 days later, taking about 8-12 days, mainly for older patients with reduced ovarian reserve function or those who do not respond well to the long regimen. Microstimulation regimen: oral administration of drugs such as clomiphene or letrozole starting on day 2 or 3 of menstruation, followed by gonadotropin 3-5 days later, mainly for older patients with poor ovarian reserve function or poor response to both long and short regimens. Regardless of the follicle development regimen used, ultrasound and hormone results should be used to determine ovarian responsiveness to the drugs and adjust the dose of gonadotropins sequentially until HCG is injected.