Comparison of a Semi-automated Closed Vitrification System (Gavi®) With a Manual Open Vitrification Sytem (Cryotop®)

The GAVI® closed vitrification system is a CE labelled device licensed for use in human IVF. It has been developed to standardize the process of vitrification and to increase the safety of the procedure. It has been demonstrated that the novel semiautomated, closed vitrification system providing standardized equilibration prior to cryopreservation can produce similar results in terms of recovery rate and Embryo development up to the blastocyst stage as compared to the commonly used Manual Cryotop® open vitrifcation system when applied in a mouse model. Furthermore, its application has resulted in first pregnancies after transfer of vitrifiedwarmed biopsied human blastocyts. Due to limitations of the preliminary studies (application in mouse model; absence of a larger clinical Trial assessing pregnancy and live birth rates in human model etc.) it is of paramount importance to compare the GAVI® vitrification method to the routinely used Cryotop® method in a human IVF setting employing randomization and a-priori sample size definitions. The primary objective of this study is to demonstrate non-inferiority of vitrification using the semi-automated GAVI® closed system over the so-far routinely used manual Cryotop® open system in terms of post-thawing survival rate of 2PN oocytes. The secondary objective of this trial is to study differences in embryo development, clinical pregnancy rate, ongoing pregnancy rate and live birth rate. Furthermore, differences in procedure duration and convenience will be evaluated.