The ovaries are the female gonads, located in the pelvis on both sides of the uterus, one on each side, responsible for the production of eggs and female hormones. Evaluation of ovarian function is an important examination for women of childbearing age before pregnancy assistance. Ovarian function is evaluated in three aspects: 1. Menstrual cycle: the normal menstrual cycle is about 28 days. As we age, ovarian function gradually decreases and begins to manifest as a shortened menstrual cycle with a period of 20-25 days, and gradually menstrual disorders and finally amenorrhea. If the menstruation has been irregular, 40 days or even once every six months or more, or if you do not take medication without menstruation, you need to pay attention to the presence of polycystic ovary syndrome. 2. Endocrine examination: 2-4 days after menstruation, blood sampling for endocrine FSH 5-10IU/L, and FSH>LH, which is normal FSH≥10IU/L, suggesting declining ovarian function FSH>25IU/L, close to ovarian function decline LH>FSH, consider polycystic ovary syndrome. 3. Ultrasound examination: 2-4 days after menstruation, transvaginal ultrasound examination of each side of the ovarian sinus follicles (2-9mm). If the number of sinus follicles (2-9mm) on each side is less than 3-5, the ovarian function is declining, and the lower the number, the more obvious the decline.