An observational study in Aneuploidy and Chromosome Abnormality, sponsored by Igenomix. Completed at 3 sites in Italy. Open to female participants aged 18 Years to 44 Years. Per ClinicalTrials.gov, last updated 2020-10-19.
Mosaicism within an embryo is defined as the presence of two or more cell populations with different genotypes. Blastocysts classified as mosaic by Preimplamtation Genetic Testing for Aneuploidy (PGT-A) have been reported to implant less and miscarry more frequently than embryos classified as euploid. Because of the unknown impact of mosaicism on embryo development, these embryos are given low priority and are discarded for transfer. However, recent papers on the transfer of human embryos classified by PGT-A as mosaic suggest that embryos with a low fraction of abnormal cells resulting in viable, chromosomally normal ongoing pregnancies, and high-level mosaics resulting in fewer viable pregnancies, but so far none producing mosaic babies.
The apparent presence of mosaicism in an embryo is used as a selection criteria for embryo transfer (ET), introducing a strong bias in terms of patient prognosis and embryo quality. Additionally, it is also possible that some embryos are incorrectly classified as "mosaic" due to technical variability derived from the processing of a uniform aneuploid embryo.
The aims of this study is to provide evidences about the clinical significance of chromosomal mosaicism in PGT-A cycles by a prospective non-selection based methodology.
One of the most common reasons why in vitro fertilization (IVF) is unsuccessful, or why miscarriages occur, is because of chromosomal abnormalities in the embryo. Embryos with less than 20% aneuploidy are considered as euploid, while those between 20-80% are reported as mosaic, and those over 80% as aneuploid. Embryos with the correct number of chromosomes (euploid) have a higher chance of leading to a successful pregnancy than those with the incorrect number of chromosomes (aneuploid) or mosaics.
Mosaicism within an embryo is defined as the presence of two or more cell populations with different genotypes. Preliminary data suggested that embryos identified as mosaic by Preimplamtation Genetic Testing for Aneuploidy (PGT-A) may have a reduced chance of implantation compared with euploid and may play a significant role in pregnancy loss.
Because of the unknown impact of mosaicism on embryo development, these embryos are given low priority and are discarded for transfer. They are transferred mostly in poor prognosis patients, explaining the reported lower clinical performances. However, other recent data regarding the transfer of embryos diagnosed as mosaic has shown that embryos with a low fraction of abnormal cells may result in viable, chromosomally normal ongoing pregnancies.
The apparent presence of mosaicism in an embryo is used as a selection criteria for embryo transfer (ET), introducing a strong bias in terms of patient prognosis and embryo quality. Additionally, it is also possible that some embryos are incorrectly classified as mosaic due to technical variability derived from the processing of a uniform aneuploid embryo. Thus, there is an urgent need to understand how to appropriately select and counsel patients regarding such embryos.
This study aims to provide evidences about the clinical significance of chromosomal mosaicism in PGT-A cycles by a prospective non-selection based methodology.
The objectives are to investigate the clinical predictive value for intermediate copy number results consistent with the presence of low mosaicism in TE biopsies, and to validate the thresholds for the classification of embryos in relation with their reproductive potential, providing comprehensive data for clinicians and patients. To demonstrate these objectives, a total of 878 participants are expected to be recruited in 18 months. As the datapoints required for comparison concern embryo transfers rather than participants, this number could be lower depending on the number of embryo transfers received by each participant.
73 studies on the registry are indexed under Aneuploidy; 10 are open to participants now.
This study's enrollment of 783 is above the median of 325 across 38 observational studies indexed under Aneuploidy.
Browse Aneuploidy studies →Igenomix is the lead sponsor of 31 studies on the registry; 3 are open to participants now.
First submitted before Igenomix became part of Vitrolife.
Counted across the registry records on this site, refreshed daily.
Embryos from In Vitro Fertilization (IVF) patients up to 44 years old (also included) with medical indication of PGT-A and own oocytes.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Embryos with a normal chromosome copy number. This embryos will be transferred to the uterus.
Diagnostic Test: PGT-A
Embryos with a lower aneuploidy percentage (\<50%). This embryos will be considered for transfer to the uterus.
Diagnostic Test: PGT-A
Embryos with a high aneuploidy percentage (50-70%). This embryos will be discarded for transfer.
Diagnostic Test: PGT-A
Embryos with an abnormal number of chromosomes. This embryos will be discarded for transfer.
Diagnostic Test: PGT-A
PGT-A will be carried out following the usual clinical practice: Trophectoderm biopsy samples from blastocysts are analyzed by NGS to screen for numerical chromosomal abnormalities.
Sustained implantation rate
Presence of a viable pregnancy after 20 weeks of gestation measured by ultrasound scan
Time frame: 20 weeks after the embryo transfer
Miscarriage rate
The spontaneous loss of an intra-uterine pregnancy prior to 20 completed weeks of gestational age.
Time frame: 20 weeks after the embryo transfer
Plan to share: No
This study is completed, as verified in Oct 2020. You cannot join it, but the record below documents what was studied.
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