Argyro Sfakianaki, BSc, MSc, Head of Midwifery Team, Assisted Reproduction Midwife
Preimplantation Genetic Testing (PGT) is a modern diagnostic procedure performed on fertilized oocytes before their transfer into the uterus during in vitro fertilization (IVF). Its primary goal is to identify genetic abnormalities or diseases that could be transmitted from the parents to the child, thereby allowing the selection of healthy embryos and reducing potential risks. Prior to undergoing PGT, patients receive comprehensive information and specialized counseling regarding the procedure and their available options.
PGT encompasses three main forms:
- Preimplantation Genetic Testing for Monogenic Disorders (PGT-M): This test screens for diseases caused by a single gene, such as hemophilia, cystic fibrosis, β-thalassemia, sickle cell anemia, Tay-Sachs disease, or Huntington’s disease.
- Preimplantation Genetic Testing for Structural Chromosomal Rearrangements (PGT-SR): This test detects structural chromosomal changes that may result in congenital anomalies, pregnancy loss, or severe cognitive and physical dysfunctions.
- Preimplantation Genetic Testing for Aneuploidies (PGT-A): This test screens for numerical chromosomal abnormalities, which are associated with miscarriages, impaired embryonic development, or IVF cycle failure.
Additionally, PGT-HLA can be performed in families with an existing child suffering from a serious disease who requires a stem cell or bone marrow donor. In such cases, the new child can be healthy and simultaneously suitable as a donor for their sibling.
Indications for PGT include:
- Carriers of genetic disorders: Couples who carry genetic conditions and face a significant risk of having a child affected by a genetic disease (PGT-M / PGT-SR).
- Recurrent pregnancy loss: Couples with two or more first-trimester losses of unknown cause, including biochemical pregnancies (PGT-A).
- Maternal age: Women aged 38 years and older using their own oocytes (PGT-A).
- IVF cycle failure: Couples with three or more failed IVF cycles, where a cycle is considered failed if β-hCG levels are <20 mIU/L at least 14 days after embryo transfer (PGT-A).
- Chromosomal abnormalities: One partner exhibits structural (PGT-SR) or numerical (PGT-A) sex chromosome anomalies on karyotype, such as Turner or Klinefelter syndrome.
The implementation of PGT requires authorization from the National Authority for Medically Assisted Reproduction, ensuring that its application complies with scientific and ethical standards. The application for authorization is primarily submitted by the IVF Unit, following the written consent of the couple or the assisted woman.
