Vitrification Versus Slow Cooling of Human Cleavage Stage Embryos

UMC Utrecht

Status: Terminated

Conditions: Infertility

Treatments: Other: embryo vitrification

Study type: Interventional

Funder types: Other

Identifiers

NCT00886431

Vitrification study

CCMO NL23499.000.08

METC 08/183

Details and patient eligibility

About

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.

Full 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

Enrollment: 146 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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146 participants in 2 patient groups

Vitrification

Experimental group

Description:

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

Treatment:

Other: embryo vitrification

Slow cooling

No Intervention group

Description:

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