Embryo Biopsy vs. PGD (Preimplantation Genetic Diagnosis) vs. PGS (Preimplantation Genetic Screening)

Infertility treatment has evolved rapidly over the last couple of years, which means   we have more tools to help our patients have healthy babies.  However, these rapid advances are sometimes difficult to comprehend –  especially when breaking down the cost. Like all IVF clinics, we rely on outside laboratories that specialize in genetic testing, utilizing either blood or cells from a developing embryo. We want to shed some light on the difference between Genetic Carrier Screening (blood tests), ICSI, Embryo Biopsy, PGS (Preimplantation Genetic Screening) and PGD (Preimplantation Genetic Diagnosis).  The following is a discussion of the specifics of what all of this means.

Genetic carrier screening is a simple blood test, drawn in our office, that can help you understand your risk of having a child with a genetic disease

When patients are in the diagnostic phase of treatment, we recommend genetic carrier screening.  Genetic carrier screening is a simple blood test, drawn in our office, that can help you understand your risk of having a child with a genetic disease. Initially, the female partner is screened and if she is not a carrier for any genetic diseases, no further testing is required. If she is a carrier, we will test the male partner. If the male partner is not a carrier, no further testing is required.

If both partners are carriers of the same genetic disease, the recommendation would be IVF/ICSI/PGD because there is a 1 in 4 chance (25%) of having a child with that disease. PGD (Preimplantation Genetic Diagnosis) of an embryo allows us to screen for a specific disease. This initial blood test is typically covered by your insurance.

If PGS or PGD is planned, then ICSI is needed. First, what is ICSI? ICSI is an acronym for intracytoplasmic sperm injection. A fancy way of saying “inject sperm into egg”. When we perform ICSI, the embryologist can isolate and inject a single sperm directly into the oocyte (egg). This ensures that only a single sperm penetrates and thus fertilizes the egg.  Because genetic material from non-fertilizing sperm can alter the nature of PGS/PGD testing, doing ICSI is absolutely necessary. Who knew the sperm who didn’t make it stayed around the egg after fertilization? Unfortunately, even when the insurance company is willing to cover the cost of IVF, individual fees for specialized procedures like ICSI and embryo biopsy may NOT be covered. Our billing team can help you understand exactly what level of coverage you have and any additional costs not covered by insurance.

What exactly is the embryo biopsy? The actual embryo biopsy is the removal of a few cells on the outer layer of the embryo that will eventually become the placenta. This is done by an embryologist in our lab using a specialized technique. The biopsied material is sent to an advanced genetic laboratory for PGS / PGD (this is the actual testing) that specializes in examining the DNA of these cells. Again, even though insurance is covering the IVF cycle, they may NOT cover the costs of performing the actual biopsies on the embryos.

So, what’s the difference between PGS and PGD???

So, what’s the difference between PGS and PGD???  PGS is the screening of the biopsied cells of an embryo to determine if the embryo has the normal number of chromosomes. It is very basic and tells us if the embryo has the normal number of chromosomes – 46,XX or 46,XY. If there are missing or added chromosomes, the embryo may be considered abnormal, and therefore not eligible for transfer back into the uterus. PGD is more specialized and can detect single gene mutations, and can help couples conceive a healthy baby even if both partners are carriers for a specific disease.

Both PGD and PGS are incredible tools that help couples conceive healthy babies. This can be such a confusing language to learn, with so many tests having almost the same initials. Don’t ever hesitate to ask us to slow down, ask us more questions, and/or ask for an explanation that makes sense to YOU! The nurses, doctors and billing team are here to answer questions that come up before, during, and even after a treatment cycle. As always, we wish you nothing but the best in your journey to a healthy baby!


Learn more about Embryo Biopsy.