Pre-implantation genetic diagnosis is an exciting new development which allows genetic evaluation of the embryo to be performed. Cells can be taken from the developing embryo on the 3rd day after fertilization and analysed to assess the karyotype or chromosome number.
The main reason this is done is to check the embryo has no chromosome abnormalities prior to replacement back into the uterus. The chromosomes that cause the most common abnormalities allowing the embryo to survive eg, Down’s Syndrome are checked. This allows us to choose better embryos for embryo transfer and is particularly useful in older women or couples who have had repeated failed IVF cycles previously. In addition the sex of the embryo can be checked and sex determination can be performed with accuracy.
PGD can also be used to detect specific gene abnormalities which is useful in patients with inherited genetic diseases.
ASSISTED HATCHING
(AH) is a procedure performed prior to transfer in selected cases. An embryo needs to escape or "hatch" from it's protein shell, called the Zona Pellucida, before it can implant in the uterus. In AH, a chemical or a laser can be used to dissolve part of the zona, to facilitate the hatching process later. This technique is often used with prior failed IVF cycles, female age over 38, and with abnormally thick zonae.
