Age-Associated Primordial Follicle Density in Human Ovarian Cortical Tissue from Post-Pubertal Females Undergoing Ovarian Tissue Cryopreservation and Transplantation: A Descriptive Analysis.

OBJECTIVE

To describe the age-associated distribution of primordial follicle density (PFD) in human ovarian cortical tissue from post-pubertal individuals undergoing ovarian tissue cryopreservation, with observations concentrated in the 20-34-year range.

DESIGN

Descriptive translational research study using log-transformed quantile regression to characterize conditional percentiles of PFD, with bootstrap resampling to assess uncertainty.

SUBJECTS: Ovarian cortical tissue from 33 post-pubertal individuals aged 16-43 years obtained from organ donors and patients undergoing ovarian tissue cryopreservation, without prior exposure to intensive alkylating agent-based chemotherapy.

EXPOSURE: Age at ovarian tissue harvesting.

MAIN OUTCOME MEASURES: Age-specific distribution of PFD (follicles/mm2), modeled across the 10th, 25th, 50th, 75th, and 90th percentiles; estimates outside the 20-34-year range are exploratory owing to sparse representation.

RESULTS

Primordial follicle density declined nonlinearly with age, with wide interindividual variability. Within the well-represented 20-34-year range (21 of 33 individuals), the estimated median PFD decreased from 1.18 follicles/mm2 at age 20 to 0.49 follicles/mm2 at age 34. Estimates at younger (16-19 years, n=2) and older (35-43 years, n=10) ages showed substantially wider bootstrap uncertainty and should be considered exploratory. An exploratory descriptive analysis of PFD and graft duration among eight ovarian transplant recipients was also performed.

CONCLUSION

This study provides a descriptive characterization of the age-associated distribution of PFD in ovarian cortical tissue prepared under contemporary fertility-preservation conditions. These findings are concentrated in the 20-34-year range and are hypothesis-generating. Larger multicenter studies linking PFD to graft function and longevity are needed before age-specific percentiles can inform individualized ovarian tissue transplantation.