Preimplantation Genetic Screening (PGS)

PGS (Pre-implantation Genetic Screening)

PGS (Pre-implantation Genetic Screening) is a test that examines the chromosomal material of an embryo before implantation. It gives new hope to women with infertility, recurring pregnancy loss, advanced reproductive age, inherited chromosomal abnormality, or those who had three or more times of in vitro fertilization failure. Using PGS we can select embryos with normal chromosomes which will result in a successful pregnancy that leads to a healthy baby. 

Before PGS, we will incubate the embryo for five days then perform laser assisted hatching.  A small gap in the outer membrane (zona pellucida) of the embryo must be made before it can be implanted in the uterine wall. Several cells of the embryo are then extracted on the fifth or sixth day of development for biopsy and analysis of chromosome. The biopsied embryo can be frozen and stored until the report is back. After the results are received, patients will have the normal embryos transferred into the uterus. 

PGD (Pre-implantation Genetic Diagnosis)

PGD (Pre-implantation Genetic Diagnosis), like PGS is a procedure designed to detect genetic abnormalities in embryos before implantation.  It can identify the presence of chromosomal and robertsonian translocations and single-gene disorders like autosomal recessive and dominant disease, and sex linked disease.  The goal of PGD is to identify abnormal embryos so they will not be transferred and to select ones that will make healthy, disease-free babies. 

Carriers of sex-linked genetic disorders and single gene disorders are good candidates for PGD. It can benefit couples at risk for conceiving a child with a genetic disorder by choosing healthy embryos for in vitro fertilization.  

PGD can test for more than 400 different conditions but only one disease is tested each time. 

Common gene disorders that can be tested by PGD 

  1. Thalassemia
  2. Spinal Muscular Atrophy
  3. Hemophilia
  4. Spinocerebellar Atrophy
  5. Ankylosing Spondylitis
  6. Bulbospinal Muscular Dystrophy aka Kennedy Disease 
  7. Nonketotic hyperglycinemia
  8. X-linked Hypohidrotic Ectodermal Dysplasia  (XLHED)
  9. Familial Amyloidotic Polyneuropathy    
  10. Color Blindness 
  11. Aniridia
  12. Congenital Adrenal Hyperplasia (CAH)
  13. Achondroplasia 
  14. Neurofibromatosis type 1
  15. Mucopolysaccharidosis II ( MPS-II) 
  16. Fabry Disease
  17. Huntington Disease
  18. Autosomal Dominant Polycystic Kidney Disease (ADPKD)