Women have approximately 400-500 eggs during their lifetime, which are developed and ovulated by mature follicles, the initiating follicles of women are present from the embryonic period. From the time of embryonic formation, the follicles start to develop and atretize on their own, a process that is not dependent on gonadotropins, that is, on the FSH follicle-stimulating hormone secreted by the pituitary gland. After puberty, the follicles develop autonomously and advance to maturity, depending on gonadotropin stimulation, which means that from puberty onwards, follicle development becomes dependent on FSH follicle stimulating hormone secreted by the pituitary gland. During the reproductive period a batch of 3-11 follicles develops each month, and after recruitment and selection, generally only one dominant follicle can reach full maturity and expel an egg. The rest of the follicles develop to a certain level and degenerate on their own through apoptosis mechanism, which is called follicular atresia. The final stage of follicular growth, which normally takes about 15 days, is the follicular phase of the menstrual cycle.