Preimplantation genetic diagnosis.

Preimplantion genetic diagnosis (PGD) is now used for identification of gene and chromosomal defects in embryos. In this article we describe its use primarily for identification of chromosomal defects in women with recurrent abortions, repeated in vitro fertilization (IVF) failure, and advanced maternal age. In all these situations there is increase in chromosomal defects. The identification of normal embryos and the elimination of abnormal embryos are argued to be helpful in increasing implantation and pregnancy rates in these women.