Genetic Testing

Fertility Treatment Options
 
Key Points

  • PGS/PGT-A checks for the correct number of chromosomes
  • PGT/PGT-M checks for specific genetic conditions.
  • Genetically normal embryos have higher implantation potential.

Types of Embryo Genetic Testing

  • Preimplantation Genetic Screening (PGS) or preimplantation genetic testing for aneuploidies (PGT-A)
  • Preimplantation Genetic Diagnosis (PGD) or preimplantation genetic testing for monogenic diseases (PGT-M)

What Do These Tests Involve?

In a normal IVF Cycle, after fertilization in the lab, the embryos develop up to day 5 (blastocyst), when they have around 150 cells. A biopsy containing a few cells (5-10) is removed from each embryo for testing.

It takes about 7-10 days for test results to arrive. Genetically normal embryos have higher implantation potential.

PGS or PGT-A

Embryos should have 46 chromosomes. PGS (pre implantation genetic screening) is also known as PGT-A (pre implantation genetic testing for aneuploidies) involves checking the number of chromosomes of embryos created by IVF. A small number of cells are removed from the embryo (biopsy) and these are tested to see if there are chromosomal abnormalities. If you have several embryos available, it may help you identify which embryos have normal chromosomes, and can be transferred.

Who can benefit from PGS?
  • Women over 37, who are more likely to have chromosomal abnormalities
  • History of chromosome problems
  • If sperm is at risk of carrying abnormal chromosomes
  • In cases of repeated miscarriages or failed IVF attempts without explanation
NGS stands for Next Generation Sequencing – is a new method of PGS/PGT-A. This method allows embryologists to screen for defects on the chromosomal level with higher accuracy and more detail. NGS results are comprehensive and a higher resolution than any other genetic testing method because it detects more translocations.

PGD or PGT-M

PGD (pre implantation genetic diagnosis), also known as preimplantation genetic testing for monogenic diseases (PGT-M), is a treatment which involves checking the genes or chromosomes of your embryos for a specific genetic condition. A small number of cells are removed from the embryo (biopsy) and these are tested for specific genetic conditions prior to embryo transfer. Breast cancer genes (BRCA1/BRCA2), Cystic Fibrosis, Sickle Cell Anaemia and Spinal Muscular Atrophy are commonly screened conditions

Who can benefit from PGD?
  • When previous pregnancies ended because of a serious genetic condition
  • When the couple already has a child with a serious genetic condition and want to avoid this happening again
  • When there is a family history of a serious genetic condition
  • When there is a family history of chromosome problems.
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