Reproductive endocrinology: Edited by David L. OliveCurrent status of human oocyte and embryo cryopreservationHerrero, Leyre; Martínez, Mónica; Garcia-Velasco, Juan A.Author Information IVI-Madrid, Rey Juan Carlos University, Madrid, Spain Correspondence to Juan A. Garcia-Velasco, MD, IVI Madrid, Avenida del Talgo 68, 28023 Madrid, SpainTel: +34 91 180 29 00; e-mail: [email protected] Current Opinion in Obstetrics and Gynecology: August 2011 - Volume 23 - Issue 4 - p 245-250 doi: 10.1097/GCO.0b013e32834874e2 Buy Metrics Abstract Purpose of review To summarize recent advances in oocyte and embryo cryopreservation techniques and outcomes. Recent findings Vitrification is gradually replacing slow freezing due to a better survival rate after thawing. Most units use vitrification for both oocyte and blastocyst cryopreservation, as these two biological structures did not perform very well with slow freezing technique. Basic experiments show that cellular damage seems lower after vitrification. Taken all together, this is helping vitirification to be expanding rapidly, and new clinical indications are being incorporated as well (i.e., fertility preservation). Summary Cryopreservation has been used as a complement to IVF, and recent publications indicate that pregnancy rates achieved with frozen oocytes and embryos are comparable with those achieved in fresh cycles. Multiple publications studying oocyte and embryo physiology during cryopreservation have been published recently; however, larger studies are needed to verify the efficacy of new cryopreservation techniques. Vitrification is a simple and robust technique that is being incorporated into the majority of IVF units, mainly for oocyte and blastocyst cryopreservation. © 2011 Lippincott Williams & Wilkins, Inc.