“Human reproduction is quite error-prone, so many embryos—even from individuals not experiencing infertility—are not viable because they don’t have the correct number of chromosomes,” explains Piraye Yurttas Beim, Ph.D., founder and CEO of Celmatix, a fertility technology company. “This can result in miscarriage, fetal death, and serious health conditions.”
According to Dr. Yurttas Beim, most individuals, regardless of where they are in the fertility treatment or evaluation process, are now offered what’s known as carrier screening. If, during that process, you find that both you and your partner are carriers of a genetic disorder, you may choose to undergo IVF so that you can test the health of your embryos before transferring them to your uterus. Freezing your eggs for potential use later? These tests may be of interest to you, too.
What’s known as preimplantation genetic testing (PGT) is split into two types of testing: PGT-A (preimplantation genetic testing for aneuploidy, also known as PGS) and PGT-M (preimplantation genetic testing for monogenic diseases, also known as PGD).
PGT-A tests embryos generated during IVF for an abnormal number of chromosomes. Chromosomal abnormalities reduce the likelihood of a successful pregnancy and can increase the risk of miscarriage or genetic disease. This test is not looking for a specific disease diagnosis, but rather screens the embryo for the normal number of chromosomes. It allows the doctor to select and transfer an embryo that is more likely to result in a successful pregnancy. PGT-A testing is typically recommended for older women or women who have had multiple miscarriages.
PGT-M looks for the presence of an abnormal gene that could lead to a health condition in the child, like cystic fibrosis, for example, before transferring the embryo to the uterus. This test is regularly used by couples who are known to be carriers of a genetic disorder.
People often find it helpful to reach out to a genetic counselor—who can help explain the potential benefits and limitations of a particular test—before or after they receive the results of any genetic test, Dr. Yurttas Beim adds.
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Editors’ note: We use the terms “woman” and “female” in this article to refer to people with internal reproductive organs; however we understand that not everyone with internal reproductive organs identifies as a woman or a female. We use the terms “man” and “male” to refer to people with external reproductive organs; however we understand that not everyone with external reproductive organs identifies as a man or a male.