Principle of PGD

Preimplantation Genetic Diagnosis (PGD) Principle of PGD Advantages and disadvantages of PGD Laboratory methods of PGD

Before the couple may undergo the preimplantation genetic examination, they are sent for an interview with a clinical genetic expert. This doctor will perform the appropriate genetic examination (especially the examination of caryotype from peripheral blood), which makes it possible to determine the risk rate of a genetic burden of the couple and recommends the optimal procedure. If the appropriateness of the PGD is concluded, the couple will undergo the IVF cycle. On the third day after the fertilisation, when the embryos achieve a stage of eight cells, the embryologist carefully collects 1 – 2 cells from every embryo. These cells undergo further steps of the genetic examination. Within this developmental stage the embryo rapidly replaces the collected cells without any damage and continues further in its development.

The result of the genetic examination is the determination of which of the embryos are, in terms of the selected genetic analysis, the healthy ones. Only these embryos are introduced into the patient’s uterus on the fourth to fifth day. The total period, which is spent by the examined embryo under in vitro conditions is the same as in the case of non-examined embryos.