When is PGD indicated?
The carriers of chromosome reorganizations, the carriers of sex chromosome alterations, carriers of mosaicisms, couples who are carriers or affected by monogenic diseases are all candidates for PDG. Sometimes a woman who has had 2 or more consecutive miscarriages and women who have failed to conceive after repeated IVF cycles are recommended to undergo PGD.
What is a PGD cycle like?
PGD consists of the following steps. First of all the couple undergoes an IVF cycle: ovarian stimulation, egg retrieval, fertilization of the eggs in the lab and embryos are formed. When the embryo has 8 cells, at more or less 2 days after fertilization, one cell is taken from the embryo. The biopsied embryo is then put back in the incubator where it develops.
The cell is extracted and examined to see if the embryo is genetically normal, DNA is extracted from the cell and for example the gene that has the mutation is amplified to determine if the embryo is a carrier of the gene mutation. This way, only healthy embryos are replaced.
