Comparison of the cryopreservation method for day 3 embryos using slow freezing or vitrification

ISRCTN ISRCTN16672665
DOI https://doi.org/10.1186/ISRCTN16672665
Secondary identifying numbers N/A
Submission date
19/11/2008
Registration date
30/01/2009
Last edited
30/01/2009
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Pregnancy and Childbirth
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Mrs Lisbet Van Landuyt
Scientific

UZBrussel
Centre for Reproductive Medicine
Laarbeeklaan 101
Brussels
1090
Belgium

Phone +32 (0)2 477 6698
Email lisbet.vanlanduyt@uzbrussel.be

Study information

Study designDouble-blinded prospectively randomised trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typeTreatment
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleRandomised controlled trial comparing the implantation potential of a frozen-thawed cleavage-stage embryo cryopreserved using vitrification or slow freezing
Study objectivesTo 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(s)Medical Ethics Committee UZ Brussel-VUB gave approval on the 6th November 2008 (ref: B.U.N B14320084732)
Health condition(s) or problem(s) studiedIn vitro fertilisation
InterventionIVF patients will receive a frozen-thawed embryo that was frozen using the vitrification method or the standard slow freezing method.
Intervention typeOther
Primary outcome measureLive birth rate per frozen-thawed embryo
Secondary outcome measures1. 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 study start date01/12/2008
Completion date01/12/2010

Eligibility

Participant type(s)Patient
Age groupAdult
SexFemale
Target number of participants306
Key inclusion criteria1. 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
Key exclusion criteriaPatients with preimplantation genetic diagnosis treatment
Date of first enrolment01/12/2008
Date of final enrolment01/12/2010

Locations

Countries of recruitment

  • Belgium

Study participating centre

UZBrussel
Brussels
1090
Belgium

Sponsor information

Research Foundation Flanders (Belgium)
Research organisation

Egmontstraat 5
Brussels
B-1000
Belgium

Website http://www.fwo.be
ROR logo "ROR" https://ror.org/03qtxy027

Funders

Funder type

Hospital/treatment centre

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

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan