PGD testing may be appropriate for couples with: Advanced maternal age (>36) Experience of repeated miscarriage Experienced repeated IVF failure Previously pregnancy with a chromosomal abnormality Risk of passing a genetic disorder on to their children Risk of having children with a particular X-linked disorder A partner who carries a balanced chromosomal translocation There are three basic types of genetic analysis performed at IRMS Chromosomal aneuploidy Chromosomal aneuploidy refers to an abnormality of chromosome number within the cells of the embryos. Normal embryos should inherit one copy of each chromosome from each parent and therefore have two copies of each chromosome. Occasionally, chromosomal irregularities arise due to errors that occur during cell division. These types of errors occur more frequently in older patients. Aneuploid embryos are unlikely to lead to a successful pregnancy, and couples at risk of producing aneuploid embryos may experience infertility. Aneuploidy