Challenges and strategies in ovarian tissue vitrification for fertility cryopreservation

Female fertility is declining globally, which has become a serious challenge for social development. Currently, the main methods of female fertility cryopreservation include cryopreservation of immature or mature oocytes, embryos, and ovarian tissue. Among them, ovarian tissue vitrification is regarded as a promising method to preserve female fertility, especially for children or adolescent women. Therefore, ovarian tissue vitrification has attracted more and more attention in recent years. Through the efforts of researchers, the technology has evolved from simple animal experiments to applications in humans. There have been cases of revived transplantation of cryopreserved ovarian tissue with successful pregnancies. However, cryo-injury, oxidative stress and other related injuries during vitrification can seriously reduce the quality of ovarian grafts and affect the therapeutic efficacy of transplantation, which are still major challenges for ovarian tissue vitrification. The purpose of this review is to summarize the challenges in the current protocols, propose relevant solutions, and provide guidance for ovarian tissue vitrification to help improve female fertility cryopreservation.