Preimplantation Genetic Screening (PGS)


Salus wants to provide every patient with a successful pregnancy and a healthy baby. Preimplantation Genetic Screening (PGS) can provide peace of mind for women who have experienced repeat pregnancy loss (miscarriage), are of advanced age, or are concerned about their proposed In-Vitro Fertilization (IVF) success rate. PGS helps doctors identify chromosomally normal embryos prior to transfer into the uterus.

What is PGS?

PGS screens for a number of common embryonic chromosomal disorders, including a condition called aneuploidy – where embryos have too few or too many chromosomes. The technique can help identify abnormalities that can cause implantation failure during IVF, as well as uncover conditions like Down syndrome (which is caused by an extra chromosome).

Studies show that the overall rate of chromosomal abnormalities in embryos is about 50 percent. As women age, the risk of chromosomal abnormalities increases and so does the risk of miscarriage from these abnormalities. PGS can help improve the likelihood of a successful pregnancy by identifying the healthiest embryos prior to embryo transfer.

How does PGS work?

To perform the test, doctors remove one or more cells from the embryo using a high-powered microscope. The biopsy process does not harm the embryo and can be done in one of two ways:

  • A cell biopsy on Day 3 multicell embryos (typically one cell is removed from each embryo)

  • A cell biopsy on Day 5/6 blastocysts (a few cells are removed from each embryo)
    Our embryology team then screens the chromosomes to check for abnormalities, extra copies of chromosomes, or missing chromosomes. Only the healthy embryos showing normal chromosome pairs are transferred into the uterus.

Who is a good candidate for PGS?

PGS is commonly offered to couples who are experiencing repeat pregnancy loss or when the woman is of advanced maternal age. We offer different levels of PGS testing based on individual risk factors and physician recommendations. The following two types of PGS analyses are used in our clinic:

  • Fluorescence In Situ Hybridization (FISH) – used for aneuploidy screening; FISH screening analyzes some (not all) of the chromosomes.
  • Microarray Comparative Genomic Hybridization (Array CGH) – used for aneuploidy screening; Array CGH analyzes all chromosomes.