caa a22 4500 445817089 CHVBK 20180317145232.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s10815-011-9674-x doi (NATIONALLICENCE)springer-10.1007/s10815-011-9674-x Maturation outcomes are improved following Cryoleaf vitrification of immature human oocytes when compared to choline-based slow-freezing [Elektronische Daten] [Catherine Combelles, S. Ceyhan, Haiyan Wang, Catherine Racowsky] Purpose: The cryopreservation of immature oocytes permits oocyte banking for patients at risk of losing their fertility. However, the optimum protocol for such fertility preservation remains uncertain. Methods: The present study investigated the survival, maturation, cytoskeletal and chromosome organization of sibling immature oocytes leftover from controlled ovarian stimulation cycles, that were either slow-frozen (with choline-substitution) or vitrified. A comparison group included oocytes that were never cryopreserved. Results: Among the three groups, comparable rates were observed for both survival (67-70%) and polar body extrusion (59-79%). Significantly more oocytes underwent spontaneous activation after IVM following slow-freezing compared with either vitrification or no cryopreservation. Likewise, the incidence of spindle abnormalities was greatest in the slow-frozen group, with no differences in spindle morphometrics or chromosome organization. Conclusions: While the overall incidence of mature oocytes with normal bipolar spindles from warmed immature oocytes was low, the yield using Cryoleaf vitrification was slightly superior to choline-based slow-freezing. Springer Science+Business Media, LLC, 2011 Immature oocyte nationallicence Choline-based slow-freezing nationallicence Cryoleaf vitrification nationallicence Spindle nationallicence Chromosomes nationallicence Combelles Catherine Biology Department, Middlebury College, 05753, Middlebury, VT, USA aut Ceyhan S. Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut Wang Haiyan Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut Racowsky Catherine Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut Journal of Assisted Reproduction and Genetics Springer US; http://www.springer-ny.com 28/12(2011-12-01), 1183-1192 1058-0468 28:12<1183 2011 28 10815 https://doi.org/10.1007/s10815-011-9674-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10815-011-9674-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Combelles Catherine Biology Department, Middlebury College, 05753, Middlebury, VT, USA aut NATIONALLICENCE 700 1- Ceyhan S. Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut NATIONALLICENCE 700 1- Wang Haiyan Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut NATIONALLICENCE 700 1- Racowsky Catherine Department of Obstetrics, Gynecology, and Reproductive Biology Brigham and Women's Hospital, Harvard Medical School, 02115, Boston, MA, USA aut NATIONALLICENCE 773 0- Journal of Assisted Reproduction and Genetics Springer US; http://www.springer-ny.com 28/12(2011-12-01), 1183-1192 1058-0468 28:12<1183 2011 28 10815 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer