In Part 1 of our menopause series, we explore two fundamental questions: Why does menopause exist, and what physiologic changes drive the menopausal transition?

Topics include:

• Definitions of perimenopause, menopause, and postmenopause
• Why humans are unusual among mammals in having a long post-reproductive lifespan
• The Mother and Grandmother hypotheses
• Chimpanzee and whale comparisons
• Oocyte development and follicular depletion
• AMH, inhibin B, FSH, and ovarian aging
• The hypothalamic-pituitary-ovarian axis
• Why menstrual cycles become irregular during perimenopause
• The physiologic foundation for menopausal symptoms

This episode lays the groundwork for future discussions of vasomotor symptoms, mood changes, hormone therapy, and modern menopause management.

References

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8. Faddy MJ, Gosden RG. A model conforming the decline in follicle numbers to the age of menopause in women. Hum Reprod. 1996;11(7):1484-1486. doi:10.1093/oxfordjournals.humrep.a019425 https://doi.org/10.1093/oxfordjournals.humrep.a019425
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