Reproductive Aging and Ovarian Reserve: Cellular Mechanisms, Biomarkers and Fertility Preservation

Reproductive aging involves depletion of the follicle pool and age-related changes in oocyte competence, ovarian somatic cells and the tissue microenvironment. These processes are related but are not measured interchangeably by ovarian reserve tests. Evidence was assessed across DNA repair, mitochondrial function, inflammatory signaling, anti-Müllerian hormone, antral follicle count and fertility preservation. Human and experimental findings implicate oxidative stress, impaired quality control and altered immune–stromal interactions, while the contribution of individual pathways varies across models. Anti-Müllerian hormone and antral follicle count are useful for estimating ovarian response but cannot independently determine oocyte quality or an individual's probability of natural conception. Oocyte and ovarian tissue cryopreservation offer established preservation pathways in selected contexts, although success estimates depend strongly on age, treatment setting and the denominator used. Proposed ovarian rejuvenation strategies remain predominantly experimental. Realistic outcome reporting and the distinction between preserving reproductive material, improving treatment response and reversing biological aging.