How do declining ovarian follicles affect fertility near menopause?

As a woman approaches menopause, the number of ovarian follicles gradually diminishes, leading to a significant decline in fertility. This process, which accelerates during the transitional phase known as perimenopause, affects fertility in several key ways:12

• Failure to Ovulate: During late perimenopause, follicles increasingly fail to rupture and release their ova. This lack of ovulation results in irregular or absent menstrual cycles, making conception difficult.2
• Reduced Ovarian Reserve: The depletion of the pool of immature follicles—which are present at birth and decline throughout a woman's life—directly limits the number of eggs available for maturation and fertilization.13
• Egg Quality: Beyond the reduction in quantity, the aging process is associated with a decrease in egg quality. This contributes to a higher risk of chromosomal abnormalities in the fetus and an increased incidence of miscarriage, as embryos may have a reduced capacity for normal implantation.3

These physiological changes reflect the natural end of a woman's reproductive life, characterized by the eventual exhaustion of functional follicles.12