Preimplantation genetic diagnosis (PGD) can be considered the earliest form of prenatal testing. It was first used in humans over 26 years ago. At its inception, PGD could only be performed for a limited number of genetic disorders. Technological advances in molecular biology and cytogenomics have been utilized in the field of PGD to greatly expand the spectrum of genetic disorders that can now be detected in early human embryos.
Keywords: Biopsy; Blastomere; Mosaicism; PGD; PGT; PGT-A; PGT-HLA; PGT-M; PGT-SR; Preimplantation genetic diagnosis; Single gene disorder; Trophectoderm.