Condition category
Pregnancy and Childbirth
Date applied
19/11/2008
Date assigned
30/01/2009
Last edited
30/01/2009
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information

Type

Scientific

Primary contact

Mrs Lisbet Van Landuyt

ORCID ID

Contact details

UZBrussel
Centre for Reproductive Medicine
Laarbeeklaan 101
Brussels
1090
Belgium
+32 (0)2 477 6698
lisbet.vanlanduyt@uzbrussel.be

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

Randomised controlled trial comparing the implantation potential of a frozen-thawed cleavage-stage embryo cryopreserved using vitrification or slow freezing

Acronym

Study hypothesis

To avoid multiple pregnancies, the proportion of elective single embryo transfers (SET) has increased substantially in our centre. Consequently, the impact of the cryopreservation program on the in vitro fertilisation (IVF)/intra-cytoplasmic sperm injection (ICSI) success rate is augmented since more surplus embryos become available. SET requires a cryopreservation program which optimally preserves the vitality of the surplus embryos. The first step to improve the efficiency of a cryopreservation program is to improve the post-thaw embryo survival. Retrospective analysis of our slow-cooling and thawing cryopreservation program showed that about 35% of day 3 cleavage stage embryos are severely damaged after freezing and thawing and are not suitable for transfer and another 15% is moderately damaged.

According to recent findings, vitrification as a new cryopreservation method is assumed to reduce cryo-damage and thus better preserves the embryo viability. During vitrification the formation of intracellular ice formation is prevented by short incubation of the embryos in high concentrations of cryoprotective agents. Successful vitrification of embryos at all preimplantation stages has been reported. Retrospective analyses show higher or similar survival and implantation rates after vitrification compared to the results obtained after traditional slow freezing and thawing. However, these data remain unvalidated in prospectively randomised studies.

The aim of the study is to compare the live birth rate after transfer of one frozen-thawed day 3 embryo using either vitrification or slow freezing as the cryopreservation method.

Ethics approval

Medical Ethics Committee UZ Brussel-VUB gave approval on the 6th November 2008 (ref: B.U.N B14320084732)

Study design

Double-blinded prospectively randomised trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet

Condition

In vitro fertilisation

Intervention

IVF patients will receive a frozen-thawed embryo that was frozen using the vitrification method or the standard slow freezing method.

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

Live birth rate per frozen-thawed embryo

Secondary outcome measures

1. Post-thaw survival of thawed embryos (the percentage of intact blastomeres on the total number of blastomeres present before freezing)
2. Post-thaw development of embryos after overnight culture
3. Implantation rate per transferred embryo
4. Ongoing pregnancy rate per thawing cycle
5. Live birth rate per transferred embryo

Overall trial start date

01/12/2008

Overall trial end date

01/12/2010

Reason abandoned

Eligibility

Participant inclusion criteria

1. Female aged less than 38 years
2. Patients with day 3 single or double embryo transfer and surplus embryos frozen
3. Cryopreservation criteria:
3.1. 6 - 7 cell embryos on day 3 with less than or equal to 20% fragmentation
3.2. Greater than or equal to 8 cell embryos on day 3 with less than or equal to 50% fragmentation
3.3. No multi-nucleated embryos

Participant type

Patient

Age group

Adult

Gender

Female

Target number of participants

306

Participant exclusion criteria

Patients with preimplantation genetic diagnosis treatment

Recruitment start date

01/12/2008

Recruitment end date

01/12/2010

Locations

Countries of recruitment

Belgium

Trial participating centre

UZBrussel
Brussels
1090
Belgium

Sponsor information

Organisation

Research Foundation Flanders (Belgium)

Sponsor details

Egmontstraat 5
Brussels
B-1000
Belgium

Sponsor type

Research organisation

Website

http://www.fwo.be

Funders

Funder type

Hospital/treatment centre

Funder name

University Hospital Brussels (Universitair Ziekenhuis Brussel [UZ Brussel]) (Belgium) - covering incidental costs

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes