Restoration of reproductive potential after autotransplantation of frozen ovaries in mice pretreated with cyclophosphamide

Purpose: Infertility due to ovarian failure that is caused by antineoplastic chemotherapeutic agents is one of the primary problems of female cancer patients who are in their reproductive years. It has become important to preserve the reproductive potential of female cancer patients. This study was conducted to determine whether autotransplantation of frozen ovaries can restore reproductive potential. Methods: This study included 30 female mice that had normal reproductive potential. The mice were divided into 4 groups: the positive control, the negative control, the comparison group, and the experimental group. The positive control group received right total oophorectomy, and the negative control group received bilateral total oophorectomy. Greater than or equal to 90% of the left ovary was removed in the mice of the comparison group, and then cyclophosphamide was administered. In the experimental group, the right ovary taken out by right total oophorectomy, and this was crypreserved using the vitrification method. And then cyclophosphamide was administered. The cryopreserved ovary was autotransplanted to the left gonadal fat pad after greater than or equal to 90% of the left ovary was removed. The reproductive performance in each group was analyzed according to the pregnancy rate after mating. Results: In the positive control group, all five mice became pregnant, and the number of fetuses was 4 to 5 (mean=4.60±0.55). In the comparison group, the pregnancy rate was 50%, and the mean number of fetuses was 1.40±0.55. In the experimental group, 7 of 10 (70%) mice became pregnant, and the mean number of fetuses was 4.71±2.56. There was no significant difference in the number of fetuses between the positive control and the experimental group (p=0.093), but there was a significant difference in the number of fetuses between the comparison group and the experimental group (p=0.019). Conclusion: The results of this study suggest that auto-transplantation of frozen ovaries using the vitrification method may restore the impaired ovarian function induced by antineoplastic chemotherapeutic agents.