Freezing immature oocytes

The establishment of a long-term preservation system for mammalian oocytes is important for the development of both biological and medical sciences. A number of efforts have been made to develop this system. In human reproduc tive medicine, the development of an oocyte cryopreservation system can imp rove the efficacy of the current assisted reproductive technology (ART) for infertile patients with severe reproductive disorders. In this article, th e technical development of cryopreservation programs for human oocytes and its biological background were reviewed. Clinical outcome after the use of this technology was further introduced. (C) 2000 Published by Elsevier Scie nce Ireland Ltd. All rights reserved.