How many follicles usually mature during the reproductive years?

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Detailed cross-sectional illustration of a human ovary showing the stages of follicle development, ovulation, and corpus luteum formation, with labeled structures including primordial, primary, secondary, and mature follicles, a ruptured follicle releasing an ovum, and corpus luteum and albicans. An inset at the bottom shows the ovary's location in the female reproductive system. — ovary The steps of ovulation, beginning with a dormant primordial follicle that grows and matures and is eventually released from the ovary into the fallopian tube.

During a woman's active reproductive years, which typically span from age 13 to 50, only 300 to 400 follicles undergo maturation.1

While thousands of immature follicles are present at the start of reproductive life, this number steadily declines over time. At the beginning of each menstrual cycle, several follicles begin to enlarge during the follicular phase, but typically only one or occasionally more are selected to reach full maturity as Graafian follicles before ovulation.1