Preimplantation Genetic Testing Helps With Embryo Selection During IVF
Preimplantation genetic testing, or PGT, is a tool that helps us choose the best embryos to transfer. PGT can determine whether embryos have genetic or chromosomal abnormalities. If the test detects a problem with a particular embryo, the embryologists won’t select that embryo for transfer, reducing the chances of a failed implantation, pregnancy loss or the birth of a baby who has a genetic disorder.
How do embryologists perform PGT?
Embryologists perform PGT on embryos at the blastocyst stage. A blastocyst is a ball made up of hundreds of cells. Most of the cell cluster is made up of cells that will become the amniotic sac, the placenta and other structures that support the pregnancy. This outer layer is called the trophectoderm, and inside that layer are the cells that will become the fetus.
For PGT, embryologists take a sample of six to eight cells from the trophectoderm of a Day 5, 6 or 7 blastocyst. After the biopsy, or cell removal, the lab freezes the embryo while they wait for the genetic testing results. Once they receive the results, embryologists go through the embryo selection process, choosing the most viable, healthy embryo for our fertility doctors to transfer to the patient’s uterus.
What are the two most common types of preimplantation genetic testing?
The experienced team at our Tulsa fertility clinic helps patients understand the risks and benefits of the two most commonly ordered types of PGT.
- PGT-A is a test for aneuploidy. If an embryo has at least one missing or extra chromosome present, the embryo is aneuploid, or chromosomally abnormal. Extra or missing chromosomes result in conditions that cause mental and physical differences. Down syndrome is one example of a condition caused by aneuploidy.
- PGT-M tests for single-gene, or monogenic, genetic disorders, such as cystic fibrosis, Huntington’s disease or Fragile X syndrome. These genetic disorders occur when a parent or parents pass on a genetic mutation to their fetus. Parents can undergo preconception genetic testing to see if they are at risk for passing on single-gene disorders to their child.
Who is a good candidate for genetic testing for embryo selection?
If patients have any of the following risk factors, they may want to talk with the team at our Tulsa fertility clinic about PGT and embryo selection.
- Women older than 35
- Women who have a history of recurrent miscarriages
- Women who have a history of IVF cycle failures
- Couples who have an increased risk of passing on a hereditary genetic disease to their child
The caring staff at our Tulsa fertility clinic can help you learn more about PGT
Our team encourages couples and individuals to ask questions about preimplantation genetic testing or any other procedure, so they can make informed decisions. Contact us for an appointment.