Abstract
To avoid the risk of contamination by bacteria, virus and prions, we compared the developmental competence of human embryos vitrified using a closed vitrification system (CVS) with that using an open vitrification system (OVS). Prospective randomized human study. This study was approved by a local IRB of IVF Namba Clinic. In experiment 1 and 2, vitrified embryos donated from patients who completed fertility treatment and gave informed consent were used. In experiment 1, 66 embryos at pronuclear stage were divided randomly into 2 groups after warming: CVS (Rapid-I, Vitrolife) and OVS (Cryotop, Kitazato medical) and were re-vitrified using CVS or OVS. After warming, embryos development and blastocysts cell number were assessed. In experiment 2, 60 vitrified-warmed blastocysts were divided randomly into 3 groups (CVS, OVS, and non-revitrified) and were assessed the proportion of dead cell by staining with Hoechst and Propidium iodide. In experiment 3, 27 high grade blastocysts were randomly divided into two groups and were vitrified using CVS (14) and OVS (13). After warming, single blastocyst transfer was performed. There were no differences between CVS and OVS in the survival rates (100% vs. 100%, respectively), the blastulation rates (Day 5: 50% vs. 50%; Day 6: 68% vs. 56%, respectively), the rate of good blastocyst (Day 5: 32% vs. 22%, Day 6: 47% vs. 41%, respectively), and the mean cell numbers (137 vs. 138) in experiment 1. In experiment 2, the proportion of dead cells in re-vitrified blastocysts were similar at 31%, 38% and 32% in the groups CVS, OVS and non-revitrified respectively. In experiment 3, the implantation rate of blastocysts vitrified using CVS (73%) was comparable to that for the OVS group (54%). The closed vitrification system overcomes the concerns associated with direct liquid nitrogen contact in the open system without impairing the developmental competence of human embryos.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
