Preimplantation genetic testing for aneuploidy: PGT-A and PGT-A+
Advancements in genetic testing now make it possible for our Las Vegas fertility doctors to select the “most likely to succeed” embryo during an IVF cycle, with a high level of accuracy. For people who need IVF to conceive, choosing preimplantation genetic testing for aneuploidy can increase the chances of a successful embryo transfer and a healthy baby. We offer two state-of-the-art options: PGT-A and PGT-A+.
Both types of tests identify which embryos created through IVF are chromosomally normal, and can also determine the sex of each embryo. Deciding whether this type of genetic testing is right for you, and which type of test to choose, is an important step when planning your IVF cycle.
How does preimplantation genetic testing for aneuploidy work?
As the first step in the genetic testing process, embryologists in our Ovation® Fertility IVF lab will remove a few cells from each embryo once they reach the blastocyst stage, around Day 5 or Day 6 post-fertilization. Taking this biopsy of cells doesn’t harm the embryo, as the sample is taken from the outer layer of the embryo, or trophectoderm, which would become the placenta. The inner cell mass that would become a baby is left untouched.
The biopsied cells are then sent to a highly specialized genetics laboratory, where their chromosomal makeup is analyzed. The embryos are cryopreserved and kept safe in our lab until the results are returned to our Las Vegas fertility doctors.
A chromosomally normal embryo has 46 chromosomes – 23 from each parent. If an embryo has the correct number of chromosomes, it is called “euploid.” An embryo that has too many or too few chromosomes is “aneuploid,” or abnormal, and would be unlikely develop normally. Transferring an aneuploid embryo could end in miscarriage, or could result in a baby with a chromosome-related disability.
What’s the difference between PGT-A and PGT-A+?
Both PGT-A and PGT-A+ can identify whether an embryo has the normal number of chromosomes. Both can also tell you the sex of each embryo, if you would like to know. Both tests can tell our physicians which embryos are the best candidates for transfer. But PGT-A+ takes preimplantation genetic testing a step further by providing additional information about the source of any chromosomal abnormalities.
In embryos that are found to have chromosomal defects, PGT-A+ can provide additional information about whether the abnormality comes from the egg, the sperm or a random error of cell division. This is especially valuable information for people who have unexplained infertility, recurrent miscarriage or a child born with a chromosome-related disability.
If you choose PGT-A+, each parent, or the egg or sperm donor, will need to provide a saliva sample. This allows the genetics lab to use each contributor’s DNA for comparison, so they can trace specific contributions to any chromosome defects found in embryos.
Who should consider adding PGT-A to their IVF cycle?
Aneuploid embryos can lead to IVF cycle failure, miscarriage and, in rare cases, birth defects. In fact, roughly half of early miscarriages are caused by chromosomal abnormalities in embryos. Some studies suggest preimplantation genetic testing for aneuploidy can achieve higher implantation rates, fewer pregnancy losses and fewer birth defects.
As a result, several groups of patients can benefit from PGT-A or PGT-A+.
- Women 35 and older who are using their own eggs
- Women who have had repeated miscarriages
- Patients who have had multiple failed IVF cycles
- People who have undergone fertility testing that didn’t identify a specific cause of infertility, known as “unexplained infertility”
- People who wish to choose the sex of their baby for family balancing or other reasons
Preimplantation genetic testing for aneuploidy can be an excellent addition to your IVF cycle if you’d like to improve your odds of having a healthy baby using IVF, and PGT-A+ can provide valuable information about the causes of any chromosomal abnormalities in embryos. Contact us to schedule an appointment with one of our Las Vegas fertility doctors to learn more about PGT-A and PGT-A+.
