OPINION Array comparative genomic hybridization: its role in preimplantation genetic diagnosis

Recent findings Data from comprehensive aneuploidy screening of embryos showed that aneuploidies may occur in any of the 24 chromosomes, indicating that aneuploidy screening of all chromosomes is necessary to determine whether an embryo is chromosomally normal. Initial studies on clinical application of this technology have documented improved pregnancy outcomes following transfer of screened embryos. The optimal stage of preimplantation development at which preimplantation genetic screening (PGS) should be performed still remains to be determined.