For the last 10 years, the techniques of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) have been used to detect genetic mutations and chromosomal abnormalities in developing embryos. It has been a revolutionary method that has resulted in reductions in the rate of miscarriage and babies with chromosome abnormalities and has accurately identified hundreds of different genetic disorders in the embryos of IVF patients.
As women age, the probability for chromosomal abnormalities increases. PGS involves removing a cell or two from the early stages of a growing embryo and analyzing the number of chromosomes. Normal human embryos contain 23 pairs of chromosomes. Commonly however, embryos will contain too many or too few chromosomes. These abnormalities which are known as aneuploidies, can lead to implantation failure, miscarriage or birth defects such as Down’s syndrome.
PGD involves removing cells from the early embryo to test for genetic mutations which can cause disease.