Genetics – PGT
What is an Preimplantation examination?
When using assisted reproduction methods, it is possible to carry out genetic testing and selection of embryos before their introduction into the uterus.
The pre-implantation examination focuses on a genetic diseases that are already present in the family, or on random genetic changes caused by the external environment, most often due to the old age of the parents.
PGT (Preimplantation Genetic Testing)
Preimplantation genetic testing (PGT) is a method that enables genetic testing of the developing embryo before implantation in the woman’s uterus. Using PGT, embryos with genetic disorders are excluded, which can be at the level of chromosomal anomalies (translocation, aneuploidy, other structural rearrangements of chromosomes) or it is a disorder of one gene, i.e. a monogenic disease.
The aim of this testing is to select a genetically healthy embryo for transfer to the uterus and thereby increase the chances of successful implantation. This method can help us eliminate the cause of possible IVF failure.
Basic types of pre-implantation examinations:
PGT-M
It is a preimplantation genetic examination of monogenic diseases with a risk of transmission from parents to the embryo. A specific variant of the gene is investigated based on previous genetic examinations of couples or the occurrence of the given disease in the family anamnesis.
PGT-A
It is a genetic examination to rule out newly emerging chromosomal defects (aneuploidy) of the embryo. It is a lack or excess of certain chromosomes or their parts.
PGT-SR
It is an examination of embryos with a risk of transmission of chromosomal structural rearrangements, most often translocations of inherited or newly formed ones.
Uses of PGT
- PGT-SR is recommended for infertile couples where the woman is over 35 (leading to a higher risk of giving birth to a child with an abnormal number of chromosomes – such as Down syndrome)
- In women who have previously miscarried or given birth to a fetus with a chromosomal defect
- In women who have experienced repeated failures during IVF cycles
- If the repeated results of the semen analysis are at the limit values
- Sperm were obtained by MESA or TESE methods
- If there is a genetic problem in the family
