Three years of routine vitrification of human zygotes: is it still fair to advocate slow-rate freezing?
- 31 December 2007
- journal article
- Published by Elsevier BV in Reproductive BioMedicine Online
- Vol. 14 (3), 288-293
- https://doi.org/10.1016/s1472-6483(10)60869-3
Abstract
Cryopreservation of human oocytes and embryos is a necessary tool in assisted reproduction treatment that leads to an increased cumulative outcome while decreasing costs. Vitrification is a cryopreservation technique that leads to a glass-like solidification, with rapid cooling of cells or tissues. Nowadays vitrification is claimed to be the future of cryopreservation of human embryos due to improved survival rates and clinical outcomes. This study was conducted at a university clinic to assess the safety and efficiency of vitrification of human zygotes as a routine procedure. A total of 849 pronuclear-stage (PN) zygotes were vitrified between March 2004 and July 2006. During this period, 103 cycles of cryopreserved embryo transfer were completed. In total, 339 PN zygotes were thawed resulting in an 89% survival rate (302 PN zygotes). The mean number of embryos per transfer was 2.2. The pregnancy rate obtained was three times higher (36.9%) than that obtained with the slow-rate freezing method (10.2%) used previously in the same centre. In conclusion, vitrification of human zygotes at the pronuclear stage seems to be a successful and reliable method with favourable outcomes and can be recommended as a routine technique for cryopreservation of human embryos.Keywords
This publication has 41 references indexed in Scilit:
- Human oocyte cryopreservation: past, present and futureReproductive BioMedicine Online, 2006
- Successful pregnancy following blastocyst cryopreservation using super-cooling ultra-rapid vitrificationHuman Reproduction, 2005
- High survival rate of vitrified human oocytes results in clinical pregnancyFertility and Sterility, 2003
- The births of five Spanish babies from cryopreserved donated oocytesHuman Reproduction, 2003
- Human oocyte cryopreservation as an adjunct to IVF-embryo transfer cyclesHuman Reproduction, 2003
- Successful pregnancies and deliveries after a simple vitrification protocol for day 3 human embryosFertility and Sterility, 2001
- Human oocyte cryopreservation: new perspectives regarding oocyte survival.Human Reproduction, 2001
- Viral Contamination of Embryos Cryopreserved in Liquid NitrogenCryobiology, 2000
- Mini-swim-up: A new technique of sperm preparation for intracytoplasmic sperm injectionJournal of Assisted Reproduction and Genetics, 1995
- Incidence of chromosome anomalies in first‐cleavage mouse embryos obtained from frozen‐thawed oocytes fertilized in vitroGamete Research, 1987