What is Preimplantation Genetic Testing (PGT)?

Preimplantation genetic testing is a preventive diagnostic technique that allows for the detection of chromosomal abnormalities (PGT-A and PGT-SR) and/or genetic analysis of a specific condition (PGT-M) in the embryo before it is transferred to the uterus.
It is a complementary technique to assisted reproduction treatments that helps select the best embryo for transfer and increases the chances of having a healthy baby.

How does the PGT work?

How is PGT performed?

1. Ovarian Stimulation and In Vitro Fertilization: To perform PGT, an IVF process is necessary, where oocytes are fertilized through ICSI and cultured until the blastocyst stage (day 5, day 6).

2. Assisted Hatching: On day 4 of development, assisted hatching is performed on the embryos to facilitate the embryo biopsy.

3. Embryo Biopsy: The embryo biopsy takes place on day 5 or day 6 at the blastocyst stage. It is essential for embryos to reach the blastocyst stage to carry out the biopsy because this stage allows for the differentiation of two structures within the embryo: the inner cell mass (which will form the baby) and the trophoblast (which will form the placenta). A laser is used to extract some cells from the trophoblast part of the blastocyst (embryo biopsy), and these cells are genetically analyzed.

4. Embryo Vitrification: The embryos are vitrified on the same day.

5. Cryotransfer: Once the PGT results are obtained, euploid embryos or those free from the studied genetic condition are transferred (CT).