Infertility
Conditions
Keywords
IVF, embryo cryopreservation, vitrification, slow cooling, slow freezing, surplus embryos, Human Reproduction
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
Interventions
OTHERembryo vitrification
Ultra rapid cooling of embryos by immersion in liquid nitrogen. The formation of potentially damaging ice crystals is prevented by briefly incubating the embryos in high concentrations of a mix of cryoprotectants.
Sponsors
Vrije Universiteit Brussel
UMC Utrecht
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* 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
Exclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 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
| Measure | Time frame |
|---|---|
| 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 thawed embryo | 10 weeks after transfer of thawed embryo |
| implantation rate per transferred thawed embryo | 10 weeks after transfer of thawed embryo |
| cumulative implantation rate per cryopreservation | 10 weeks after thawed embryo transfer |
| ongoing pregnancy rate per frozen-thaw cycle | 10 weeks following thawed embryo transfer |
| post-thaw embryo survival rate | 1 hour after thawing |
| post thaw development (categorial) per thawed embryo | 24 hours following thawing |
| average number of cryo-thaw cycles to ongoing pregnancy | variable, up to 3 years |
| average number of thawed embryos to ongoing implantation | variable, up to 3 years |
| Life birth rate | 9 month after pregnancy test |
| average number of frozen-thawed cycles per patient | is variable |
Countries
Belgium, Netherlands
Outcome results
None listed