Genetic Testing Basics
Preimplantation genetic testing (PGT) is a valuable tool for fertility specialists to make decisions that improve fertility outcomes. This test allows the fertility team to assess the genetic makeup of embryos used during in vitro fertilization (IVF) or other forms of assisted reproduction. Using only a sample of cells from developing embryos, a genetic technician can use unique technology to assess the chromosomes or genetic markers. PGT-A tests for aneuploidy, which are missing or abnormal chromosomes. PGT-M searches for monogenic/single-gene defects. This is an extensive list of potentially inherited conditions, including sickle cell anemia and Down’s syndrome. PGT is not mandatory for IVF’s success, so ask the doctor these 3 questions before proceeding.
1. Why would I need genetic testing?
The greatest benefit is for couples who are over 35 and have experienced recurrent pregnancy loss. There may be an underlying issue on the genetic level that conventional tests cannot uncover. Genetic abnormalities are higher with advanced maternal age, so testing helps to identify embryos with these issues. Couples with known genetic disorders within the family should consider genetic testing to reduce the chances of passing an inherited disease onto the child. Genetic testing is a valuable tool to reduce miscarriages and improve live birth rates.
2. How would the results affect my future treatment?
PGT needs additional time to be completed, but the results will guide the fertility team for the next cycle. The team can identify which embryos are healthier and more likely to result in a successful pregnancy. Using the results and past data, the fertility team can change hormone protocols around implantation or suggest other treatments to improve success rates. Couples must also navigate the additional costs of PGT, including testing and additional embryo cryopreservation.
3. What if PGT reveals all embryos are abnormal?
Testing may reveal an unavoidable genetic condition. If there are chromosomal abnormalities, the team will conclude that the embryos are not suitable for implantation. Some embryos may be mosaic, having a mixture of normal and abnormal chromosomes. While classified as abnormal, these embryos can result in a healthy pregnancy, but the risk of failure is much higher. The couple and team will then decide if to perform another PGT test or proceed with the IVF cycle. Some couples may opt to restart the egg and sperm retrieval process to create new embryos. These tests are an opportunity to discuss other options like donors or adoption.
Make an informed decision
PGT is an innovative method for determining if failed IVF cycles are due to an underlying genetic abnormality. By using advanced testing techniques on an embryo biopsy, fertility clinicians reveal new information that can guide the fertility process. Testing for chromosomal abnormalities helps couples decide on donors or start over the IVF cycle with new embryos. Identifying genetic conditions can help avoid potential diseases. PGT is effective but not 100% accurate. There are variances in data, and PGT cannot identify some conditions. The medical team will discuss the potential for false positives or negatives. Almost all cases provide fantastic accuracy that successfully guides treatment. Use PGT to make an informed decision and raise the bar on IVF success.
