Preimplantation genetic screening (PGS) is a technique in which one or more cells are taken from an egg or embryo (fertilized egg) for testing to provide information about the genetic make-up of the rest of the cells in that embryo. In order to utilize PGS, couples must undergo in vitro fertilization (IVF), where the eggs (oocytes) are removed from a woman’s body and mixed with her partner’s sperm in a laboratory. The embryos which are created can be tested on Day #5-7 after egg harvest. At IVF Phoenix, these embryos will be frozen after the cells are removed for testing and implanted in a subsequent frozen embryo transfer cycle attempts.
Patients with many inherited familial diseases can have their embryos tested with preimplantation genetic diagnosis (PGD) to determine if a specific gene is present or absent. Specifically, this would include patients with a history of single-gene disorders (such as cystic fibrosis or sickle cell anemia) and patients with a history of sex-linked disorders (such as Duchenne muscular dystrophy and Fragile X syndrome). In addition, even families in search of a bone marrow donor may be able to use PGD to bring a child into the world that can provide matching stem cells for an affected sibling.
Other patients may also decide to use genetic screening called PGS. For some patients with recurrent pregnancy loss, severe male factor infertility, advanced reproductive age or recurrent IVF treatment failures, genetic screening may be used. Genetic screening is different than other types of genetic testing because the testing is looking for any gross chromosomal abnormality instead of a specific disease, and as a result is associated with higher rates of false results. The literature has shown the highest rates of ongoing pregnancy rates for all age groups when transferring a chromosomally normal or euploid embryo with frozen embryo transfer.
If you are uncertain about genetic testing for you, speak with Dr. Couvaras about whether preimplantation genetic testing is right for you.