Prospective randomized comparison of human oocyte cryopreservation with slow-rate freezing or vitrification

• Autor(a) principal: Smith, Gary D.
• Data de Publicação: 2010
• Outros Autores: Serafini, Paulo C., Fioravanti, Joyce, Yadid, Isaac, Coslovsky, Marcio, Hassun, Pericles, Alegretti, Jose Roberto, Motta, Eduardo L. [UNIFESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• dARK ID: ark:/48912/001300000pfw7
• DOI: 10.1016/j.fertnstert.2009.12.065
• Texto Completo: http://dx.doi.org/10.1016/j.fertnstert.2009.12.065; http://repositorio.unifesp.br/handle/11600/33003
• topic: Prospective randomized study; human oocyte cryopreservation; slow-rate freezing; vitrification; pregnancies

Objective: To compare cryopreservation of mature human oocytes with slow-rate freezing and vitrification and determine which is most efficient at establishing a pregnancy.Design: Prospective randomized.Setting: Academically affiliated, private fertility center.Patient(s): Consenting patients with concerns about embryo cryopreservation and more than nine mature oocytes at retrieval were randomized to slow-rate freezing or vitrification of supernumerary (more than nine) oocytes.Intervention(s): Oocytes were frozen or vitrified, and upon request oocytes were thawed or warmed, respectively.Main Outcome Measure(s): Oocyte survival, fertilization, embryo development, and clinical pregnancy.Result(s): Patient use has resulted in 30 thaws and 48 warmings. Women's age at time of cryopreservation was similar. Oocyte survival was significantly higher following vitrification/warming (81%) compared with freezing/thawing (67%). Fertilization was more successful in oocytes vitrified/warmed compared with frozen/thawed. Fertilized oocytes from vitrification/warming had significantly better cleavage rates (84%) compared with freezing/thawing (71%) and resulted in embryos with significantly better morphology. Although similar numbers of embryos were transferred, embryos resulting from vitrified oocytes had significantly enhanced clinical (38%) pregnancy rates compared with embryos resulting from frozen oocyte (13%). Miscarriage and/or spontaneous abortion rates were similar.Conclusion(s): Our results suggest that vitrification/warming is currently the most efficient means of oocyte cryopreservation in relation to subsequent success in establishing pregnancy. (Fertil Steril (R) 2010; 94: 2088-95. (C) 2010 by American Society for Reproductive Medicine.)