RESUMEN
Objective To compare the effect of different cryoprotectants and different concentrations on controlled?rate freezing of human ovarian tissues. Methods Ovarian tissues were sampled from 15 patients undergoing benign ovarian tumor surgery. Cortical slices were frozen by controlled?rate freezing using three cryoprotectants,propanediol,ethanediol,and dimethylsulphoxide,and the concentration of each cryoprotectant was 1.5 mol/L or 2.0 mol/L. Cortical slices obtained from each patient were processed with each cryopreservation procedure simultaneously. Morphology of fol?licles was studied by light and electron microscopy and the normal rate was compared with that of the fresh tissues from the patient. Results There were no significant differences in distribution of follicles of different developmental stages between each group(P0.05). However,the difference was statistically significant for 1.5 mol/L PROH,2.0 mol/L PROH, 1.5 mol/L DMSO and 2.0 mol/L DMSO groups(P0.05). Conclusion Controlled?rate freezing using 1.5 mol/L EG as the cryoprotectant can better save oocytes and granulosa cells. It is a preferable freezing procedure for ovarian tissues.