**2.8 Preimplantation genetic diagnosis (PGD)**

Preimplantation genetic diagnosis (PGD) is useful in patients with a family history of genetic disorders. It may be recommended in couples with repeated miscarriages or failure in IVF or in elder patients say 35 years old or above [14].

Aneuploidy is a term used to describe an abnormality in chromosome number (fewer or more of a specific chromosome). Aneuploidy screening is performed in cases of advanced maternal age, repeated IVF failure, recurrent miscarriage and previous aneuploidy pregnancy [15].
