Understanding preimplantation genetic screening
Preimplantation genetic screening happens during the IVF process. The test is not mandatory but can help tremendously in some instances. For example, if a woman was experiencing miscarriages and failed IVF cycles, PGS rules out any abnormalities. During IVF, the fertility clinic creates embryos by combining extracted egg and sperm samples. Around day 5, an embryologist takes a biopsy of a few cells to send for genetic testing. The lab turn analyzes the DNA to confirm if the embryo has the correct number of chromosomes. The right number of chromosomes means the embryo is healthy and ready to implant.
Does it apply to frozen embryos?
Frozen embryos are those placed on ice for later use using a process called vitrification. Luckily, these same frozen embryos are eligible for genetic screening. The fertility lab must first thaw the embryo, then take the biopsy. Since the clinic is unsure of the integrity of one, multiple embryos are thawed. A sample from each goes to the lab for genetic analysis. The results go back to the lab. If there are many with healthy chromosomes, one (or two) is readied for implantation. Some clinics even allow the patient to choose an embryo. The rest goes back under the ice.
A common myth between embryos and PGS
This is not hyperbole. Embryos are pretty sensitive and can easily damage during the freezing process, thawing process, and yes, even through biopsy. There are a lot of people who therefore believe that PGS is both harmful and unnecessary. Yet, the process is relatively safe for the embryo and baby. Over the years, PGS has improved in efficacy. The method extracts only a few cells. These cells are called trophectoderm, believed to be part of the placenta. That means the inner cells that create the embryo remain unharmed.
Can PGS affect pregnancy success rates?
Initial studies show there seems to be no relationship between the biopsy and failed pregnancies. While there needs to be more concrete research, fertility clinics perform hundreds of screenings per year with high success. One can argue that PGS does the opposite. Women with advanced maternal age, multiple miscarriages, and failed IVF cycles may have find greater advantages of PGS.
PGS makes all the difference
PGS helps clinics to make the right decisions concerning embryo transfers. The test rules out embryos with incorrect chromosomes, increasing safety and success rates. Luckily, clinics can perform tests on frozen embryos as well. More importantly, the tests do not harm the embryo or future baby. If there seems to be no traction with IVF or embryo transfer, consider speaking with a doctor about PGS.