What are PGS and PGD?
Preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD) are different ways to test embryos for genetically normal characteristics. Dr. Parikh finds them helping in increasing the potential for a pregnancy and baby for couples undergoing IVF.
These tests determine the genetic makeup of a small sampling of cells from your embryo. While both of these tests offer a picture of the genetic makeup of an embryo, they differ slightly in the information they glean.
Preimplantation genetic screening checks for the presence of the correct number of chromosomes — the building blocks of the genetic code. While an abnormal number of chromosomes may signal some conditions, this test cannot identify specific genetic disorders.
Preimplantation genetic diagnosis screens for specific genetic disorders, such as cystic fibrosis. This test incorporates genetic data from both parents to help identify abnormalities of the embryo’s DNA that point to a genetic disorder.
Using this information, the unaffected embryos are chosen for implantation.
Who should have PGS and PGD?
Dr. Parikh consults with each of her patients to determine if PGS and PGD are important tests for them.
Patients who may also benefit from this type of genetic testing are women over the age of 35 or others who may have:
- A family history of genetic disorders
- Multiple miscarriages
- Unexplained infertility
- Unsuccessful IVF cycles
- Male factor infertility
Using PGS and PGD decreases the risk of passing down known genetic disorders and helps identify healthy embryos for implantation.
How do PGS and PGD work?
In the case of both tests, a small sampling of cells is taken from an embryo. This testing is done at the blastocyst stages of an embryo’s development.
At Advantage Women’s Care, PGS and PGD testing are done using trophectoderm biopsy, when the embryo is made up of around 200-300 cells. This is about 5-6 days after fertilization. Testing at this stage decreases the risk of damage to the embryo and increases the chances of an accurate diagnosis.
PGS results can take a few days, and up to a few weeks for PGD. Your embryos are frozen while results are pending, and implantation occurs later. Dr. Parikh discusses the results with you and your partner in her office, and he offers compassionate support all along the way.
To discuss PGD and PGS testing with Dr. Parikh, call or book your appointment online today.