Preimplantation genetic testing (PGT) is a screening test performed on embryos obtained through in vitro fertilization (IVF) to perform genetic analysis of the embryos before they are transferred to the mother's body.

One of the most common reasons for pregnancy failure after embryo transfer is abnormal genetics of the embryo. With the help of PGT, one with the right number of chromosomes can be selected, the so-called Euploid embryo, thus reducing the chance of failed IVF cycle and miscarriage.

women older than 37 years (due to reproductive aging, the risk of abnormal embryo genetics increases); Couples who are at risk of having a child with an inherited genetic disease; Couples with a history of repeated miscarriages due to chromosomal abnormalities.

After the eggs are retrieved and fertilized in the laboratory, the embryologist biopsies a few cells from the embryo and sends it to the laboratory for genetic analysis.

Preimplantation genetic testing for aneuploidy (PGT-A), formerly known as preimplantation genetic screening (PGS), is a method of examining the embryo to determine the number of chromosomes in the cells.

Genetic testing is performed in a laboratory before the embryo is transferred into the mother's body. A healthy person has 46 (23 pairs) chromosomes. Embryos with a complete set of chromosomes are called euploid, while embryos with an abnormal number of chromosomes are called aneuploid. Most embryonic aneuploidies are incompatible with life. After implantation in the uterus, they fail to develop and cause spontaneous abortion. There is a small fraction of aneuploidies compatible with life, such as for example

Autosomal chromosomal aneuploidies:

• Trisomy 21 - Down's syndrome
• Trisomy 18- Edwards syndrome
• Trisomy 13 - Patau syndrome

Aneuploidy of the sex chromosome:

• 47 XXY-Kleinfelter syndrome in men
• 45 XO – Turner syndrome
• 47 XXX- triple X syndrome
• 47 XYY- Jacobs syndrome.

With increasing age, the risk of aneuploidy in women increases dramatically.

Preimplantation genetic testing for aneuploidy (PGT-A) is used to calculate the number of chromosomes in each embryo and identify euploid (healthy) embryos. In addition, this test allows to protect women from emotional stress and complications related to spontaneous abortion.

PGT-A consists of the following stages: When the patient begins in vitro fertilization (IVF), the development of the embryo to a certain stage takes place outside the body, in the IVF laboratory. It is at this time that the embryo biopsy is performed. On the fifth or sixth day, when the embryo reaches the blastocyst stage, a trophectoderm biopsy is performed (a trophectoderm sample usually includes 3-5 cells, but the margins are variable and may be 3-10 cells or more). The trophectoderm is a component of the blastocyst, which later becomes the placenta; The cells from which the fetus is formed are not damaged during the procedure. Biopsy material is sent to our laboratory for genetic testing.

After the procedure, the embryos are cryopreserved and the results of the genetic test show that when thawed, the embryos recover and develop normally.