Preimplantation genetic testing (PGS & PGD)
Pre-implantation genetic screening (PGS)
PGD is used to screen embryos for chromosomal abnormalities. These types of abnormalities increase as women get older, but they can occur at any age. They can cause failure to achieve pregnancies, miscarriages, or severe abnormalities in children such as Down’s syndrome.
Pre-implantation genetic diagnosis (PGD)
PGD allows couples undergoing in vitro fertilization (IVF) for infertility to screen their embryos for a specific genetic disease that runs in their family, such as sickle cell anemia.
How is PGD/PGS performed?
PGD/PGS is performed after a woman’s oocytes (eggs) have been retrieved and before the embryos are transferred into the uterus. Intracytoplasmic sperm injection (ICSI) must be used to fertilize the eggs that will undergo PGS/PGD. ICSI uses a single sperm for fertilization to avoid contamination from other sperm. Next, 3 to 4 cells are extracted (biopsied) from day 5 blastocyst stage embryos (that contain 60 to 80 cells), while retaining the integrity of the embryo for future development and growth.
The embryo biopsy and PGS are both performed in the CReATe PGS laboratory by our embryologists and PGS laboratory technicians. Because we uniquely have our own PGS Laboratory at CReATe, we do not have to ship biopsies to a separate genetics laboratory, minimizing costs and avoiding shipping costs and risk of loss. Once the biopsy is completed, the cells are analyzed over the next 5 to 10 days.
PGD testing is performed at an outside laboratory, except for a specific genetic abnormality called a translocation (which is performed at CReATe). Both PGS and PGD can be performed on the same embryo.
The results of the genetic analysis will be reviewed by your physician. In most cases of PGS/PGD, the embryos must be frozen for future frozen embryo thaw cycle(s).
PGD/PGS and Pregnancy
The biopsy procedure is very safe and more accurate when performed at the blastocyst stage (day 5) of development. Therefore, it poses only a very small risk of damage or cell death to the developing embryo.
Transferring an embryo that is determined to be normal by PGD/PGS genetic screening does not guarantee that it will result in a pregnancy and a healthy baby, but it significantly increases the odds. Not all genetic or other types of abnormalities can be, or will be, detected by PGD/PGS screening. In addition, while the tests are very accurate, they are not a guarantee. No test can rule out the presence of any genetic disease with 100% certainty. Therefore, PGD/PGS testing does not eliminate the need for considering subsequent routine genetic screening during a pregnancy. This should be discussed with your obstetrician or midwife.
PGS is not a routine part of IVF. To have PGS done, couples will need to pay an extra fee for the biopsy procedure and the PGS testing procedure performed in CReATe’s PGS laboratory (see CReATe’s IVF fee information form).
If PGD is indicated for a specific disease in your family, CReATe will contact an outside PGD testing facility at the beginning of your cycle to initiate the preparation process for PGD testing. The facility will contact you directly for billing purposes once they receive the information from us. In some cases, both PGD and PGS will be recommended by your doctor & both of these will be performed together at an outside PGD testing facility. The biopsy prior to PGD testing will be performed at CReATe & billed by CReATe separately. The outside testing facility will provide you with a separate consent for PGD.
If your doctor, in consultation with you, determines that PGS at CReATe will be cancelled for any reason, you will not be charged for the biopsy or testing.
If you have any further questions please do not hesitate to discuss them with your physician.