In assisted reproduction, it is possible to perform genetic testing and selection of embryos created in the process before implantation.
Preimplantation testing should focus either on genetic diseases that are already present in the family or on random genetic changes caused by external environment – which one of the most important is the age of parents.
We distinguish two types of preimplantation examination:
PGD (preimplantation genetic diagnosis) – examination of embryos to exclude hereditary disease in the family.
PGS (preimplantation genetic screening) – examination of embryos to exclude new emerging chromosomal defects which could occur in couples without genetic disorders.
PGD (Pre-implantation diagnostics)
Pre-implantation genetic diagnostics (PGD) is a method which enables genetic screening of the developing embryo before it is inserted into a woman’s uterus. PGD is used to eliminate embryos with genetic disorders, which could be on the level of chromosomal anomalies (translocation, aneuploidy, other structural chromosome reconfiguration) or this may concern a single gene disorder, e.g., a monogenic disorder.
PGS (Pre-implantation genetic screening)
Pre-implantation genetic screening (PGS) is used to eliminate newly originating chromosomal abnormalities. The aim of this method is to choose a genetically healthy embryo for the transfer and thus increase the chance of successful implantation. This method can help us determine the cause of IVF failures.