Assessment of the New Automated Vitrification System "GAVI" for Early Cleaved Embryos Cryopreservation

The meta-analysis comparing the cryopreservation of human embryos by vitrification or slow-freezing suggested that more well design studies as randomized trials are necessary to identify the most successful method for cryopreservation. The efficacy of the vitrification with the GAVI system will be compared with the conventional slow freezing method through a randomized control trial. Couples in IVF attempt will be randomized at the day of embryo cryopreservation by the biologist. Supernumerary frozen embryos will be thawed and transferred in utero in case of failure of the "fresh" embryo transfer. The outcomes of the thawing and frozen/thawed embryo transfer will be assessed. In the two groups, the patients will benefit of the standard IVF procedures applied in the Assisted Reproductive Technologies (ART) center of Toulouse.