Vitrification Versus Slow Cooling of Human Cleavage Stage Embryos

Sponsor

UMC Utrecht (Other)

Overall Status

Terminated

CT.gov ID

NCT00886431

Collaborator

Vrije Universiteit Brussel (Other)

146

Enrollment

Locations

Arms

Patients Per Site

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Infertility	Other: embryo vitrification	N/A

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

Study Design

Study Type:

Interventional

Actual Enrollment :

146 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Participant, Care Provider)

Primary Purpose:

Treatment

Official Title:

A Double Blinded, Randomised Controlled Trial Comparing the Effectiveness of Vitrification to Slow Cooling in Cryopreserving Human Preimplantation Embryos

Study Start Date :

May 1, 2009

Actual Primary Completion Date :

May 1, 2012

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Vitrification The embryos of patients allocated to this arm will be cryopreserved by vitrification.	Other: embryo 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. Other Names: vitrification high security vitrification straws
No Intervention: Slow cooling The embryos of patients allocated to this arm will be cryopreserved by the slow cooling method, which is the standard method (=no intervention)

Arm

Intervention/Treatment

Experimental: Vitrification

The embryos of patients allocated to this arm will be cryopreserved by vitrification.

Other: embryo 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.

Other Names:

vitrification

high security vitrification straws

No Intervention: Slow cooling

The embryos of patients allocated to this arm will be cryopreserved by the slow cooling method, which is the standard method (=no intervention)

Outcome Measures

Primary Outcome Measures

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

post-thaw embryo survival rate [1 hour after thawing]
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]
average number of frozen-thawed cycles per patient [is variable]
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]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 35 Years

Sexes Eligible for Study:

All

Accepts 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