Glossary · Conditions

Ovulation

Definition: Ovulation is the release of a mature egg from the ovary, typically occurring around day 14 of a 28-day menstrual cycle. The mid-cycle LH surge triggers ovulation. Anovulatory cycles become more common in late perimenopause as ovarian reserve declines.

Detailed definition

Ovulation is the rupture of a dominant ovarian follicle and release of the mature oocyte into the fallopian tube. It typically occurs 24–36 hours after the LH surge, around the middle of a regular menstrual cycle. Following ovulation, the residual follicle becomes the corpus luteum, which produces progesterone for the luteal phase. Anovulatory cycles — cycles in which no egg is released — become increasingly common in late perimenopause as ovarian reserve declines, contributing to the cycle irregularity that defines this stage. Anovulation is also a feature of PCOS and various other endocrine conditions.

Why it matters in menopause

In late perimenopause, irregular periods reflect a mix of ovulatory and anovulatory cycles. Anovulatory cycles produce unopposed estrogen exposure (no luteal-phase progesterone), which is one mechanism behind the heavy or irregular bleeding many women experience. The 52-mg LNG-IUD or cyclic progesterone can manage this.

Sources

External references: Wikipedia.

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