Not necessarily. In women with normal ovarian function, during the natural cycle, a group of sinus follicles (about 3-11) in the ovary will enter the growth and development track together under the action of follicle-stimulating hormone (FSH) in the late luteal phase of the previous menstrual cycle and the early follicular phase of the current menstrual cycle, a process called recruitment. The growth of the recruited follicles is mainly dependent on gonadotropins, especially follicle-stimulating hormone (FSH), and the follicles can only continue to grow if the FSH level reaches or exceeds a certain threshold. The follicle with the lowest FSH threshold, i.e., the follicle that is the most sensitive to FSH, will be prioritized to develop into the dominant follicle, whereas the other follicles will gradually become atretic. There can be more than one follicle recruited in a cycle, but usually only one dominant follicle eventually develops and ovulates. What is needed in an IVF cycle, however, is controlled superovulation with exogenous ovulation stimulating drugs, mostly exogenous FSH, so that follicles other than the dominant follicle can continue to develop in order to achieve the goal of obtaining multiple mature eggs without being limited by the natural cycle. However, the number of sinus follicles seen under ultrasound in the luteal phase or early follicular phase is not necessarily the number of eggs that can eventually be retrieved. There are several reasons: 1, ultrasound error: the diameter of the sinus follicle is only 2~5mm, different machines, different sections and different doctors may see different numbers of sinus follicles. Sinus follicles with smaller diameters may not be seen, and small blood vessels and cysts within the ovary may be mistaken for sinus follicles. 2. Each follicle has a different sensitivity to FSH, and each patient has a different responsiveness to ovulation stimulating drugs. The starting dose of ovulation drugs is calculated by the doctor according to the patient’s age, BMI, basic reproductive hormone levels, the number of sinus follicles, etc. It is only an empirical medication, and each patient’s response is different, so it is not necessarily that each follicle can synchronize the development of the same time to mature. 3, the loss of egg retrieval: generally 34~36h after the night injection to retrieve eggs, but some patients, especially patients with reduced ovarian function, there may be early ovulation or empty follicle phenomenon, resulting in the number of eggs retrieved less than the number of follicles monitored by the previous ultrasound. Other patients may be obese or have poorly positioned ovaries, which may interfere with the egg retrieval procedure and result in the loss of eggs. In order to retrieve the most suitable follicles, you must follow the doctor’s instructions to regularly monitor blood hormone levels and ultrasound, and take ovulation stimulation injections and night injections on time.