What is the Difference Between PGD and PGS?

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Learn About PGD and PGS in NY

Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS) are two different tests that may take place prior to implanting an embryo into the uterus during the IVF process. These two tests are both very important for different reasons, and may or may not be necessary for specific patients. Today we will help you learn a bit more about PGD and PGS, the differences between these two tests, and when it may be important to inquire about these tests when trying to get pregnant.

Preimplantation Genetic Diagnosis

Preimplantation Genetic Diagnosis, or PGD for short, is a genetic test that allows reproductive specialists to pick the best possible embryo for implantation during the IVF cycle. It tests to determine if a specific genetic disease is present in any or all of the embryos in order to select the embryo with the strongest chance of survival.

Do you need a PGD test?

While anyone undergoing IVF is considered for PGD, it is most beneficial to couples who are at a higher risk of having specific genetic diseases passed on to the fetus. For example, if both partners are carriers for a specific genetic disease (even if they don’t actually have the genetic disease) there is an increased risk it will be present in the embryo. PGD would be able to rule that out and increase the likelihood of carrying a healthy pregnancy to term.

Preimplantation Genetic Screening

Preimplantation Genetic Screening, or PGS for short, is also a test of the embryo. This test, however, screens for chromosomal abnormalities. Humans have 23 pairs of chromosomes. When there is less or more than this amount, problems arise and the embryo usually will not survive. In some cases it does survive, such as when there is an extra 21st chromosome, resulting in Down’s Syndrome.

Do you need a PGS test?

PGS tests are highly recommended for anyone going through IVF and women with multiple miscarriages. Detecting chromosomal abnormalities in an embryo prior to implantation can make a huge difference in the success rates of a pregnancy. When testing the cells of multiple embryos, a reproductive specialist will be able to choose one for implantation that has no chromosomal abnormalities and thus the highest chance of resulting in a live birth. Women over the age of 38 who are interested in single embryo transfer should highly consider a PGS test.

It should be noted that PGS does not test for specific genetic disease, and for that a PGD test would be needed.

Weighing Your Options

When it comes down to it, you should listen to the recommendations of your reproductive specialist when determining which preimplantation tests you should have done. The specific tests recommended will depend on your medical history, past miscarriages, number of successful/unsuccessful IVF cycles, genetic markers and more. Many couples choose to do both tests as a precautionary measure and to increase their chances of a successful and healthy pregnancy.

Learn More About PGS and PGD

If you would like to learn more about PGS and PGD testing in New York, then do not hesitate to contact the professionals at NYU Langone Reproductive Specialists of New York today. We have offices in Brooklyn, and Mineola are prepared to help you achieve a healthy and safe pregnancy.