title: Embryo vitrification using a novel semi-automated closed system yields in vitro outcomes equivalent to the manual Cryotop method.
abstract: OBJECTIVE
  Can the equilibration steps prior to embryo vitrification be automated?
  
  
  CONCLUSIONS
  We have developed the 'Gavi' system which automatically performs equilibration steps before closed system vitrification on up to four embryos at a time and gives in vitro outcomes equivalent to the manual Cryotop method.
  
  
  BACKGROUND
  Embryo cryopreservation is an essential component of a successful assisted reproduction clinic, with vitrification providing excellent embryo survival and pregnancy outcomes. However, vitrification is a manual, labour-intensive and highly skilled procedure, and results can vary between embryologists and clinics. A closed system whereby the embryo does not come in direct contact with liquid nitrogen is preferred by many clinics and is a regulatory requirement in some countries.
  
  
  METHODS
  The Gavi system, an automation instrument with a novel closed system device, was used to equilibrate embryos prior to vitrification. Outcomes for embryos automatically processed with the Gavi system were compared with those processed with the manual Cryotop method and with fresh (non-vitrified) controls.
  
  
  METHODS
  The efficacy of the Gavi system (Alpha model) was assessed for mouse (Quackenbush Swiss and F1 C57BL/6J x CBA) zygotes, cleavage stage embryos and blastocysts, and for donated human vitrified-warmed blastocysts. The main outcomes assessed included recovery, survival and in vitro embryo development after vitrification-warming. Cooling and warming rates were measured using a thermocouple probe.
  
  
  RESULTS
  Mouse embryos vitrified after processing with the automated Gavi system achieved equivalent in vitro outcomes to that of Cryotop controls. For example, for mouse blastocysts both the Gavi system (n = 176) and manual Cryotop method (n = 172) gave a 99% recovery rate, of which 54 and 50%, respectively, progressed to fully hatched blastocysts 48 h after warming. The outcomes for human blastocysts processed with the Gavi system (n = 23) were also equivalent to Cryotop controls (n = 13) including 100% recovery for both groups, of which 17 and 15%, respectively, progressed to fully hatched blastocysts 48 h after warming. The cooling and warming rates achieved with the Gavi system were 14 136°C/min and 11 239°C/min, respectively.
  
  
  CONCLUSIONS
  Testing of the Gavi system described here was limited to in vitro development of embryos from two mouse strains and a limited number of human embryos. Validation of Gavi system advanced production models is now required to confirm the success of semi-automated vitrification, including clinical evaluation of pregnancy outcomes from the transfer of Gavi vitrified-warmed human embryos.
  
  
  CONCLUSIONS
  The Gavi system has the potential to revolutionize and standardize vitrification of embryos and oocytes. The success of the Gavi system shows that it is possible to semi-automate complicated labour-intensive ART methods and processes, and opens up the possibility for further improvements in clinical outcomes and efficiencies in the ART clinic.
  
  
  BACKGROUND
  This study was funded by Genea Ltd. S.B., N.M.T., T.T.P., S.J.M., M.C.B. and T.S. are shareholders of Genea Ltd. E.V., C.H., C.L., S.R.L. and S.M.D. are shareholders of Planet Innovation Pty Ltd. The remaining authors are employees of either Genea Ltd. or Planet Innovation Pty Ltd.
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia tammie.roy@geneabiomedx.com.au.
authors.forename: Tammie K
authors.initials: TK
authors.lastname: Roy
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Susanna
authors.initials: S
authors.lastname: Brandi
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Naomi M
authors.initials: NM
authors.lastname: Tappe
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Cara K
authors.initials: CK
authors.lastname: Bradley
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Vom
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Chester
authors.initials: C
authors.lastname: Henderson
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Craig
authors.initials: C
authors.lastname: Lewis
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Kristy
authors.initials: K
authors.lastname: Battista
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Hobbs
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Hobbs
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Syer
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Sam R
authors.initials: SR
authors.lastname: Lanyon
authors.affiliation: Planet Innovation, 81-89 Cotham Road, Kew, VIC 3101, Australia.
authors.forename: Sacha M
authors.initials: SM
authors.lastname: Dopheide
authors.affiliation: Genea Biomedx, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Teija T
authors.initials: TT
authors.lastname: Peura
authors.affiliation: Genea, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: McArthur
authors.affiliation: Genea, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Bowman
authors.affiliation: Genea, 321 Kent Street, Sydney, NSW 2000, Australia.
authors.forename: Tomas
authors.initials: T
authors.lastname: Stojanov
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer / Q000379:methods*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D051379:Mice; D011247:Pregnancy; D058989:Vitrification
keywords: IVF; automation; embryo; standardization; vitrification