Transplantation of cryopreserved ovarian tissue in a series of 285 women: a review of five leading European centers.

The feasibility of freezing and thawing ovarian tissue is nowadays widely documented. However, ovarian tissue transplantation (OTT) is happening at a much slower pace, and clinical experience is somewhat limited. In this review, five European centers present their collective experience of transplanting ovarian tissue in 285 women. The focus is on surgical techniques and OTT outcomes, reproductive outcomes, the impact of chemotherapy before ovarian tissue cryopreservation (OTC), the risk of relapse, and endocrine resumption and longevity of transplanted tissue. The risk of relapse due to reimplantation of ovarian tissue appears to be very low according to current data. Recovery of endocrine function is seen in almost all women undergoing transplantation of ovarian tissue, and about one in four gives birth to a healthy child. The efficacy of in vitro fertilization in these patients is not very high, however, and needs to be substantially improved. Radiation to the pelvis, especially with relatively high doses, appears to considerably decrease the likelihood of a successful pregnancy and may be contraindicated. Our results demonstrate that chemotherapy before OTC does not impair the chances of success, depending, of course, on the total dose and type of chemotherapy administered. At this early stage of development of OTT for restoration of fertility, the results are encouraging and demonstrate clear potential. However, the method is far from being fully developed and requires continued research efforts to optimize our approach.