Vitrification Versus Slow Cooling of Human Cleavage Stage Embryos

Infertility Clinical Trial

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

Status Terminated

Clinical Trial 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.

Clinical Trial 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

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Infertility

• NCT number: NCT00886431
• Study type: Interventional
• Source: UMC Utrecht
• Status: Terminated
• Phase: N/A
• Start date: May 2009