Minimize your chances of miscarriage and maximize your chances for a healthy pregnancy with Preimplantation Genetic Diagnosis or Preimplantation Genetic Screening. Dr. John Park clearly explains how embryo biopsy can detect single gene defects (like cystic fibrosis or spinal muscular atrophy), chromosomal rearrangement (like balanced translocation), and aneuploidy (the presence of an abnormal number of chromosomes), all BEFORE an embryo is transferred back into the uterus.