Oxidative Stress–Telomere Axis in IVF: Molecular Mechanisms, Biomarkers, and Clinical Translation

The reduction in oocyte competence and ovarian reserve coincides with reproductive ageing; nevertheless, the molecular mechanisms underlying this phenomenon remain poorly understood. Our testable mechanistic hypothesis is that the oxidative stress-telomere axis is a crucial regulatory mechanism controlling meiotic stability, mitochondrial resilience, and granulosa cell integrity. This notion posits that granulosa and cumulus cells have accelerated telomere attrition and impaired DNA-damage responses due to elevated amounts of reactive oxygen species, which also induce oxidative guanine lesions, inhibit telomerase function, and generate telomeric replication stress. This telomere-dependent vulnerability is anticipated to compromise developmental competence, disrupt meiotic spindle integrity, and diminish metabolic support to the oocyte, prior to observable declines in AMH or follicle count. Data from human IVF cohorts supports the model: Conditions such as PCOS, endometriosis, and POI have unique oxidative-telomeric profiles, whereas diminished telomere length in granulosa cells, reduced telomerase activity, and worse fertilisation, blastulation, and pregnancy outcomes are associated with increased follicular oxidative DNA damage. The findings suggest that oxidative DNA damage (8-OHdG), telomerase activity, and the structure of granulosa-cell telomeres may serve as preliminary indicators of preclinical ovarian ageing. This theory may be directly evaluated in forthcoming longitudinal studies and specific treatments related to telomerase regulation, mitochondrial medicines, or redox modulation. Consequently, the oxidative stress-telomere axis may represent a vital physiologic factor affecting reproductive lifespan and a prospective target for personalised ART techniques.