Transplantation of frozen–thawed late-gestational-age human fetal ovaries into immunodeficient mice

ObjectiveTo compare the development of human fetal follicles from late-gestational-age fetuses frozen–thawed gradually and slowly with dimethylsulfoxide (DMSO) or 1,2 propanediol (PROH) and sucrose after renal grafting into follicle stimulating hormone-treated immunodeficient mice.DesignControlled histologic study of grafted human fetal ovaries.SettingMajor tertiary care academic center.Patient(s)Eleven women undergoing pregnancy termination at 22 to 33 gestational weeks.Intervention(s)None.Main Outcome Measure(s)Microscopic morphometric analysis and immunohistochemistry for proliferating cell nuclear antigen (PCNA).Result(s)Only follicles from samples frozen–thawed with PROH developed to secondary and antral stages 4 to 6 months after grafting, with PCNA expression in their granulosa cells. However, the number of surviving/developing follicles per section was very low (4–25 per graft), compared with 71 to 406 follicles in pretransplantation samples. Graft recovery was very high, with similar rates for transplants frozen–thawed with PROH and DMSO. Normal ovarian structure after grafting was identified only in the PROH frozen–thawed grafts. In deteriorated grafts, frozen–thawed with either DMSO or PROH, net-like hollows replaced follicles, whereas tubule-like structures were only identified in DMSO frozen–thawed grafts.Conclusion(s)This is the first report of the development of late-pregnancy-stage human fetal follicles in immunodeficient mice. PROH freezing–thawing supported development and survival better than DMSO. However, the low follicular survival points to the urgent need for efficient methods to enhance vascularization rate and prevent ischemia.