Preimplantation genetic testing (PGT) of the embryo

In specific clinical situations clearly defined by the Reproductive Medicine Act (FMedG), it is allowed and possible to genetically analyze a small number of embryonic cells.

In order to undergo preimplantation genetic testing (PGT), the couple must go through a complete IVF/ICSI cycle.

The costs of a PGT are never covered by the Austrian IVF Fund, but the costs of the IVF/ICSI cycle, which is the main part of a PGT, can be co-financed by the IVF Fund if the appropriate requirements for registration with the IVF Fund are met.

Medical indications for PGT treatment include:

• Three or more past IVF/ICSI treatment cycles in which implantation failed
• Three or more miscarriages (spontaneous miscarriages) documented by ultrasound
• A known chromosomal abnormality and/or a known gene mutation in at least one parent that may lead to a genetic disease in the child (Note: only strictly defined mutations can be legally tested; the list of these diseases is constantly updated)

The first 6 steps of a PGT treatment are essentially the same as the course of IVF/ICSI treatment (3rd IVF/ICSI). Instead of embryo transfer of a blastocyst, which takes place on the fifth day after egg retrieval in IVF/ICSI treatment, our biologists perform an additional step : a biopsy of the trophectoderm, i.e. the outer layer of the embryo from which the placenta will form. The biopsied embryo itself is then vitrified, i.e. frozen.

Note: the part of the embryo from which the fetus will later develop is never biopsied. Only a few trophectoderm cells are extracted, which are specially prepared and then sent to a specialized genetic laboratory for further analysis.

Please note: Since the biopsied embryo must be frozen during the biopsy of the trophectoderm cells, a fresh embryo transfer is never possible during a PGT treatment cycle.

In a further step , the cells of each biopsied embryos in a specialized genetic laboratory (not in our clinic!). Please note: The more embryos biopsied and genetically analyzed, the greater the probability that at least one of them is completely healthy, i.e. without chromosomal abnormality and/or targeted gene mutation that was the reason for the PGT.

Normally, the analysis is completed within a week. If healthy embryos are found, treatment is continued with the next step.

Please note: There is a possibility that the genetic analysis of some (or, rarely, all) embryos cannot be carried out or is inconclusive for technical reasons. There is also a chance that all biopsied and tested embryos are not healthy. In this case, embryo transfer is not possible.

If at least one embryo is found without chromosomal abnormality and/or targeted gene mutation (which was the reason for the PGT), the next step is a simple embryo transfer of the selected, unaffected embryo. This and all other steps are now the same as for standard IVF/ICSI treatment (3rd IVF/ICSI).