ABSTRACT
Preimplanation genetic screening (PGS) and diagnosis (PGD) are techniques that provide genetic and chromosomal information about developing embryos through biopsy and analysis of embryonic cellular material. This technology is applicable and helpful to many couples seeking conception through IVF, particularly those with a known risk of transmitting single gene disorders to their offspring or those at risk of generating embryos with structural or numeric chromosomal abnormalities. In couples using PGD, accurate and reliable determination of single gene defects, chromosome structure, and chromosome number in blastomere or polar body biopsies is used to guide embryo selection prior to transfer. For many, this is a far more desirable option than awaiting fetal diagnosis in the first or second trimester of pregnancy via chorionic villus sampling or amniocentesis. While continuing to rapidly expand, PGD has become a routine option for patients to prevent the transmission of known single gene diseases and to enhance the chance of pregnancy and live birth for couples with repeated IVF failure, recurrent pregnancy loss, or advanced maternal age.
