Vitrification Versus Slow Cooling of Human Cleavage Stage Embryos
- Conditions
- Infertility
- Interventions
- Other: embryo vitrification
- Registration Number
- NCT00886431
- Lead Sponsor
- UMC Utrecht
- Brief Summary
Human embryos can be preserved for later transfers by freezing. Traditionally the slow cooling method has been used. About 70% of the embryos remain fully intact after thawing. However, the remaining 30% of the embryos become (partially) damaged, and this freezing damage reduces their chance to implant. Recently an ultra rapid freezing method, called vitrification has been developed. During vitrification no damaging ice crystals are formed and the embryo freezes in a glass like state.
It appears that the freezing damage is reduced when embryos are vitrified. Observational studies in humans indicate that embryos are successfully preserved by vitrification, as indicated by promising pregnancy rates following thawing. However, the effectiveness of vitrification in relation to slow cooling with respect to pregnancy rates has so far not been evaluated by a randomised, controlled trial. The aim of this study is to investigate whether vitrification significantly improves embryo survival and ongoing pregnancy rates when compared to embryos frozen by slow cooling.
- Detailed Description
time of allocation: following embryo selection
type of embryos: cleavage stage -, morula stage or early blastocyst stage embryo (day3 - day4 after oocyte collection)
cryoprotectants: sucrose, dimethylsulfoxide, ethyleneglycol
vitrification storage device: high security vitrification straws
Recruitment & Eligibility
- Status
- TERMINATED
- Sex
- All
- Target Recruitment
- 146
- female patient age 35 years or less
- embryos are obtained by in vitro fertilization (IVF) or intra cytoplasmatic spermatozoon injection (ICSI)
- single embryo transfer
- 1rst IVF/ICSI treatment with an embryo transfer
- availability of cryopreservable embryos
- female patient age is 36 years or older
- participants of oocyte donation program
- participants of percutaneous spermatozoon aspiration (PESA) program
- couples with a finite source of spermatozoa
- absence of cryopreservable embryos
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Vitrification embryo vitrification The embryos of patients allocated to this arm will be cryopreserved by vitrification.
- Primary Outcome Measures
Name Time Method The percent change of the ongoing pregnancy rate per patient/couple who use their thawed embryos (following a fesh embryo transfer which did not result in an ongoing pregnancy) from baseline (slow cooling) to end point (vitrification). ongoing pregnancy is established 10 weeks following the transfer of a frozen embryo
- Secondary Outcome Measures
Name Time Method post-thaw embryo survival rate 1 hour after thawing implantation rate per thawed embryo 10 weeks after transfer of thawed embryo cumulative implantation rate per cryopreservation 10 weeks after thawed embryo transfer ongoing pregnancy rate per patient using their thawed embryos (independent of whether they became pregnant following a fresh embryo transfer or not 10 weeks following transfer of frozen thawed embryo implantation rate per transferred thawed embryo 10 weeks after transfer of thawed embryo ongoing pregnancy rate per frozen-thaw cycle 10 weeks following thawed embryo transfer average number of frozen-thawed cycles per patient is variable average number of thawed embryos to ongoing implantation variable, up to 3 years post thaw development (categorial) per thawed embryo 24 hours following thawing Life birth rate 9 month after pregnancy test average number of cryo-thaw cycles to ongoing pregnancy variable, up to 3 years
Trial Locations
- Locations (2)
Academic Hospital of Brussels
🇧🇪Brussels, Belgium
University Medical Center of Utrecht
🇳🇱Utrecht, Netherlands