Preimplantation Genetic Testing
PGT-A : Preimplantation Genetic Testing for chromosomal Aneuploidies
PGT-M : Preimplantation Genetic Testing for Monogenic defects
PGT-S : Preimplantation Genetic Testing for Structural rearrangements
We offer our patients the opportunity to genetically test their embryos created during an IVF treatment. This is only indicated in specific cases:
- High risk cases for chromosomal abnormalities (mostly age-related)
- Couples who are both carriers of monogenic defects and want to avoid the occurrence of the disease in their offspring
- Patients with structural translocations who wish to avoid chromosomal abnormalities in their offspring
Young women undergoing IVF treatment, who have no known genetic problems, do not require genetic testing of the embryos, as it is unlikely that their embryos will have any genetic problems.
The genetic testing of embryos
The genetic testing of embryos is performed in our center through a laboratory procedure known as “embryo biopsy”. This procedure involves creating embryos through the normal IVF process, culturing them to the blastocysts stage on Day 5/6, and using microtools to remove a small number of cells from the outer part of the embryo in order to send those cells to the genetic laboratory that will perform the testing.
Receiving the genetic results
Biopsied embryos are cryopreserved through the vitrification method and stored in our freezing facility until we receive the genetic results. Patients receive counseling from the embryologist and their doctor regarding the results and their options for further action. Embryos that have been found to be genetically healthy are transferred upon request of the patient during a frozen embryo transfer (FET) cycle.
Types of genetic testing
Pedieos IVF Center offers 3 different types of genetic testing of embryos. All genetic analyses are performed by collaborating genetic laboratories using state-of-the-art technologies such as Next Generation Sequencing (NGS).
1. PGT-A
This is a new preimplantation genetic testing for chromosomal aneuploidies (PGT-A). PGT-A is recommended for:
- Patients who wish to transfer only embryos which have been found to be genetically euploid (normal) and have the best chance of developing to a healthy pregnancy. Women of advanced maternal age (more than 38) fall into this category.
- Patients who wish to avoid the invasive procedure of prenatal testing during their pregnancy, thus transferring only genetically healthy embryos in an IVF cycle.
- Patients who have had repeated miscarriages, repeated implantation failures or given birth to a child with a genetic, chromosomally-related abnormality.
2. PGT-M
For patients who are carriers of a certain genetic disorder, specifically a monogenic or single gene defect and do not wish to pass this on to their offspring. Some examples of these defects are β-Thalassaemia and Cystic Fibrosis.
3. PGT-S
For patients who are carriers of a structural rearrangement, such as reciprocal or Robertsonian translocations and wish to avoid transferring unbalanced chromosomes to their offspring. This test is named PGT-S (preimplantation genetic testing for structural rearrangements).
Additional information
Please note that patients requiring PGT-A can proceed with treatment and genetic testing as soon as they are ready. However, for couples that a PGT-M testing of a rare monogenic disorder is required, a preparation period may be needed by the genetic lab before the patients can start treatment.
We have to provide various details needed in order for the genetic lab to develop the correct testing kit for each case. This waiting time will depend on the rarity of the genetic disease.