2.4 Embryology Techniques

Vitrification (cryopreservation) and embryo banking:

Vitrification is an innovative flash-freezing technique for oocytes, embryos and ovarian tissue. This fertility preservation procedure, which has a 98% survival rate, allows you to store surplus embryos created in one cycle for later use.

Genetic testing

Numerous diseases and disorders classified as chromosomal disorders, single gene defects and sex-linked disorders can be tested for through a technique called pre-implantation genetic diagnosis (PGD).

PGD involves the removal and biopsy of several cells from the embryo when the embryo has reached the blastocyst stage. At the day 3 stage, when the embryo consists of just six to eight cells, a single cell is removed. Biopsies taken at the day 5 stage, when the embryo has about 100 cells, are more indicative. At the day 5 stage, your doctor will remove three or four cells from the trophectoderm, the part of the blastocyst that will become the placenta.

PGD is performed for all single gene defects where the specific mutation is identifiable. Analysis of the cells occurs by fluorescent in situ hybridization (FISH), a diagnostic method used to show the number and arrangement of chromosomes. PGD is an early screening technique and it does not entirely rule out the chance of a defect being present. For this reason, PGD should be followed up with first-trimester screenings.