Advances in indications of preimplantation genetic diagnosis/screening

Abstract

Controversies in indications of preimplantation genetic diagnosis (PGD)/preimplantation genetic screening (PGS) are developing with the rapid improvement of the technology for years. PGD is clearly indicated for monogenetic diseases, chromosome abnormalities and HLA typing, while PGS is ambiguous in indications, with the purpose to improve fertility rate and take-home baby rate for patients suffered from recurrent spontaneous abortion (RSA), recurrent implantation failure and advanced maternal age. However, the first generation PGS technology [PGS#1, biopsy of blastomere plus fluorescent in situ hybridization (FISH)-PGS] has failed to provide promising clinical effect, and to the contrary decreased the fertility and take-home baby rate. The second generation PGS technology (PGS2.0), which is focused on biopsy of blastocyst plus comprehensive chromosome screening (CCS) and adds severe male infertility factor as an indicator, has shown promising clinical effect of decreased abortion rate and increased fertility and take-home baby rate. PGS2.0 has dramatically changed features of assisted reproductive technology, and may probably become a routine item for all patients in reproductive centers in the future. Multicenter prospective random case control study is still needed for revaluate effect of PGS. Key words: Preimplantation genetic diagnosis (PGD); Preimplantation genetic screening (PGS); Assisted reproductive technology (ART); Fluorescent in situ hybridization (FISH); Comprehensive chromosome screening (CCS)