Preimplantation Genetic Screening and Diagnosis (PGS/PGD)

What is PGS and PGD?

Preimplantation Genetic Screening or Preimplantion Genetic Diagnosis (PGD/PGS) is a technique that can be used in conjunction with In-Vitro Fertilization (IVF) to test embryos for genetic disorders prior to their transfer to the uterus. PGS can be considered for couples experiencing repeat pregnancy loss due to chromosomal disorders. PGD makes it possible for couples with serious inherited disorders to decrease the risk of having an affected child and for couples that already have one child with a genetic disorder and are at high risk of having another.

PGS/PGD is performed using a high-powered microscope. A few cells are removed from the blastocyst embryo and tested for either a normal number of chromosomes or the genetic trait of interest. The unaffected embryos are identified, separated from the affected embryos, and transferred into the uterus. Our embryologists typically perform a cell biopsy on Day 5 or Day 6 blastocysts (a few cells are removed from each embryo). The biopsied cells are processed by our embryology team according to the type of PGS or PGD requested. Depending on the reason the couple is pursuing PGS/PGD, the following types of analyses are used:

  • Single Gene Analysis for specific inherited disorders, such as Cystic Fibrosis, Fragile X, Myotonic Dystrophy, Thalasaemia, Tay Sachs, and others.

  • Microarray Comparative Genomic Hybridization (Array CGH) for aneuploidy screening to identify embryos with a normal number of chromosomes, benefiting couples experiencing repeat pregnancy loss or women of advanced maternal age. Array CGH analyzes all chromosomes.

    PGS/PGD involves many benefits and risks, and our physicians will discuss these topics with you during your consultation.