Preimplantation genetic screening (PGS)

Human karyotype

In cases of repeated failed IVF attempts, especially for women of advanced age, in couples with normal karyotype and severe male infertility, or in cases of repeated early pregnancy loss, the embryos may undergo preimplantation genetic screening (PGS). Embryos are biopsied and isolated blastomeres are tested for the presence of structural or numerical chromosome abnormalities using special cytogenetic methods (FISH). However, this method can only identify up to 9 chromosomes, and therefore is associated with a high degree of misleading results.