ABSTRACT
In the mid-1980s and during the successive decade, the cryopreservation of human mature oocytes was believed to be unfeasible in consideration of the existing knowledge and technology. In effect, the fi rst reports on the use of frozen oocytes in the clinical setting were in many respects rather disappointing and overall unable to prove the applicability of this form of fertility preservation (1,2). In the last few years, however, studies of fundamental cryobiology (3), empirical observations (4) and more systematic clinical experiences (5-10) have generated a renewed interest in this subject. More rational and theoretical approaches could provide the key to the development of methods able to guarantee greater success (11,12). Currently, several clinics offer oocyte cryopreservation as a form of treatment worldwide. Italy provides an extreme example where, as an effect of the introduction of a very restrictive legislation, oocyte cryopreservation has been adopted rather diffusely as an alternative to embryo freezing, and treatment cycles can be counted in their thousands. Oocyte cryopreservation is attracting additional interest as a tool for better management of oocyte donation cycles (see chap. 23). Future studies will need to address the issue of the actual effi ciency of oocyte cryopreservation, in order to provide IVF specialists with criteria to enable them to measure performance and, in the fi nal analysis, guide patients in their choices among different treatment options.
