Under normal circumstances, women only ovulate one egg a month. After the end of menstruation, several follicles gradually develop together, and only 1-2 follicles develop into the dominant follicle. During the further development of the dominant follicle, only one follicle will eventually develop into a mature follicle and ovulate. As the dominant follicle develops into a mature follicle and ovulates, the other small follicles gradually shrink. Individually, two or three dominant follicles can develop and ovulate in 4 weeks, which is one of the reasons for multiple births. When patients have endocrine disorders, such as polycystic ovary syndrome and hyperprolactinemia, they show multiple small follicles without mature follicles developing and ovulating. If a woman has ovarian disorders such as inflammation of the ovaries and chocolate cysts, she can present with luteinization of the follicles without ovulation occurring.