Preimplantation Genetic Diagnosis (PGD) is applied in the context of in vitro fertilization and allows us to check the genetic material of eggs or embryos before they are transferred to the uterus.
Its purpose is to identify chromosomal or hereditary abnormalities, in order to select for implantation the embryos with the best chances of leading to a healthy pregnancy.

At what stage is the biopsy performed?

PGD ​​can be performed at three different stages of embryonic development, depending on the case:

1. Blastomere biopsy (3rd day of development)
   When the embryo has reached the 6–8 cell stage, 1–2 cells (blastomere) are removed for genetic testing.

2. Polar body biopsy (before fertilization)
   By removing the first or second polar body, we can check the genetic composition of the egg before it unites with the sperm.
   This is an indirect test, as it concerns exclusively the maternal genetic information.

3. Βιοψία πολικών σωματίων (πριν τη γονιμοποίηση)
   Με την αφαίρεση του πρώτου ή του δεύτερου πολικού σωματίου μπορούμε να ελέγξουμε τη γενετική σύσταση του ωαρίου πριν ενωθεί με το σπερματοζωάριο.
   Πρόκειται για έμμεσο έλεγχο, καθώς αφορά αποκλειστικά τη μητρική γενετική πληροφορία.

What information does PGD offer us?

• polar body biopsy allows us to check only the genetic material that comes from the mother.

• Embryo biopsy (blastomere or trophoblast), on the other hand, makes it possible to detect genetic abnormalities that may come from both the mother and the father.

The material obtained is sent for specialized genetic testing to identify possible mutations or chromosomal abnormalities.

Technique selection

The biopsy method and type of genetic testing are chosen based on:

• family and medical history,

• the existence of known genetic diseases,

• the woman's age,

• and the characteristics of sperm and embryos.

The doctor explains in detail which method is most appropriate for each case, with the aim of increasing the chances of a safe and healthy pregnancy.