The PPOS program, also known as the Program for Promotion of Ovulation in a High Progesterone State (PPOS), refers to the luteal phase ovulation promotion. The specific steps are using drugs after ovulation, and taking drugs during luteal phase. 1. Use of drugs after ovulation: Some patients can use drugs to promote ovulation after ovulation, such as oral drugs combined with injectable drugs or injectable drugs can be used alone. Generally, oral progesterone is used to form an artificial luteal phase during the menstrual period, such as the use of dextroprogesterone, amphetamine progesterone and other drugs. The use of oral progestins is accompanied by the option of subcutaneous or intramuscular injections of ovulation-promoting drugs such as human chorionic gonadotropin and urogesterone. When the follicle and estrogen levels are eligible, the trigger will take the eggs. 2. Luteal phase taking drugs: in the artificial luteal phase taking ovulation drugs and ovulation, in vitro ovulation, trigger, at this time there may be follicles in the early follicular stage, continue to inject ovulation drugs, such as human chorionic gonadotropin, urotropin, etc., to wait for the follicle to develop and mature and then trigger, for the real luteal phase of the promotion of ovulation. Therefore, the artificial made luteal phase or the true luteal phase, basically the ovulation promotion program and steps are the same. The above ovulation promotion and trigger steps are called PPOS program. Ovulation induction treatment should be carried out under the guidance of a medical professional.