1. Polar Body Analysis2. Blastomere Biopsy on day 3 embryos3. Trophectoderm - Biopsy on Blastocysts
Pre-Implantation Diagnostics (PID) or Pre-Implantation Genetic Diagnosis (PGD) as it is known in Anglo American countries has originally been developed as an alternative to prenatal diagnosis which is only possible when a pregnancy is established, whereas PID/PGD can be performed on the embryo prior to the achievement of a pregnancy.
The PID/PGD is performed by examining a single cell with regard to aneuploidy
mal-distribution) and genetic diseases (overview, genetic diseases
in detail, example: retinoblastoma
). This can either be done by using the Polymerase Chain Reaction
(PCR) or the Fluorescence In Situ Hybridization
The PID/PGD also permits HLA-genotyping in embryos. HLA-genotyping is a valuable approach if there is a medical indication, e.g. a child suffering from a severe disease and whose life may be saved through the use of stem cells harvested from the umbilical cord blood
of an HLA-identical sibling (such as e.g. Fanconi-Anemia, leukemia, auto-immune diseases…).
If, due to a malignant disease, a child’s bone marrow cells have been destroyed as part of the chemotherapy or radiotherapy treatment, the sick child’s only chance of survival is either a matching bone marrow donation from a sibling or another suitable donor or the transplantation of stem cells from a cord blood donor to rebuild the hematopoietic system.
1. Polar Body Analysis
Polar body testing allows conclusions to be drawn regarding the mother’s genetic contribution (oocyte) to the embryo. In this way it is possible to confirm or rule out the mal-distribution of chromosomes and the genetic predisposition towards certain diseases with a high degree of probability.
This technique can be used to reduce the risk of miscarriage especially in patients of advanced maternal age and it may lead to slightly increased pregnancy rates. We are pleased to provide you with further details on this technique during a personal consultation.
2. Blastomere Biopsy on day 3 embryos
The biopsy is performed by removing a single cell or a maximum of two cells (blastomere
) from the embryo, usually on the 3rd day after fertilization at the 6 - 8 cell stage.
This diagnostics is used mainly in cases of a specific genetic condition
running in a family and is specifically designed to diagnose whether an embryo is also a carrier of the genetic condition of concern. Only the embryos that are predicted to be free of the genetic condition are used for embryo transfer.
In certain cases, this diagnostics can be suitable for investigating chromosomal disorders (aneuploidies) (e.g. reciprocal translocations
To date, Polar Body Testing still is the “Gold Standard” in aneuploidy-screening. We were able to show this together with the late Yury Verlinsky
.Reference 1Reference 2
We offer blastomere analysis for PGD/PID at our IVF-Center in Pilsen
in the Czech Republic.
3. Trophectoderm Biopsy on Blastocysts
The analysis of cells removed from the blastocyst on day 5 of embryonic development (trophectoderm biopsy
) is a technique that we are still in the process of further developing together with Alan Handyside
(pioneer in the field of PGD). This technique is not yet routinely on offer at our centers.
For the future we hope that, due to this technique, we will be in a position to detect chromosomal disorders (aneuploidy
) as well as genetic diseases (overview, genetic diseases
in detail) using a single diagnostic method (whereas to date, it is necessary to combine the methods of polar body testing
and blastomere biopsy on day 3 embryos).
Analyzing blastocysts requires optimum freezing methods
, since this procedure mostly exceeds the maximum period for which embryos can be kept in culture. We are proud to count among our longtime staff members, Dr. Pierre Vanderzwalmen
, who is a pioneer in the field of cryopreservation.References