Increase the Chance of Success
Preimplantation Genetic Testing (PGT) in Indiana
When it comes to assisted reproductive technology, many patients want to increase their chances of having a successful pregnancy. In vitro fertilization (IVF) on its own is a highly effective treatment option, but there are other advanced procedures that can improve your chances of conceiving even more. One of these options is preimplantation genetic testing (PGT). At Indiana Fertility Institute, we understand the emotional investment that fertility care requires and how important it is for patients to use every tool available in pursuit of their family-building goals. PGT diagnostic testing is just one of the many advanced treatment options we offer to help you on your fertility journey.
When is Preimplantation Genetic Testing Recommended?
If a patient is unable to conceive or sustain a pregnancy, it is sometimes caused by genetic or chromosomal abnormalities in the embryo, which typically occur at random. PGT makes it possible to identify embryos that have no genetic or chromosomal defects so that they can be used in an IVF cycle. While not a guarantee, PGT can dramatically increase the chances of having a successful and healthy pregnancy.
PGT is also frequently recommended for patients who have known genetic disorders that could potentially be passed down to their children.
Who Can Benefit from Preimplantation Genetic Testing?
PGT is a cutting-edge form of assisted reproductive technology that can provide peace of mind in many different scenarios. This includes patients who:
- Have a history of recurrent pregnancy loss (i.e. two or more miscarriages)
- Have an inheritable genetic disorder
- Have experienced multiple failed IVF cycles
- Are of advanced maternal age
What is Preimplantation Genetic Testing?
In a cycle of IVF, PGT is the process of biopsying a small sample of cells from an embryo’s outer tissue, also known as the trophectoderm, which later develops into the placenta. This does not harm the embryo in any way, as the inner cell mass (i.e. the part of the embryo that will eventually develop into the fetus) remains untouched during the process. The biopsied cells are then analyzed for genetic defects, depending on the type of PGT test that is being done. The goal is to identify embryos that are genetically normal. Meanwhile, the embryos are frozen.
Types of Preimplantation Genetic Testing
There are three different subtypes of PGT testing. All three are performed the exact same way, but are used in different scenarios.
Preimplantation Genetic Testing for Aneuploidy (PGT-A)
PGT-A, also known as preimplantation genetic screening (PGS), is used to count the number of chromosomes an embryo has. A normal human embryo has a total of 46 chromosomes, inheriting 23 chromosomes from each parent. When an embryo has too few or too many chromosomes, it is known as aneuploidy disorder. These disorders can hinder normal development and result in certain congenital conditions or miscarriages. Well-known conditions caused by aneuploidy disorders include:
- Down syndrome
- Edwards’ syndrome
- Patau syndrome
- Turner syndrome
- Klinefelter syndrome
Preimplantation Genetic Testing for Monogenic Disorders (PGT-M)
PGT-M, also known as preimplantation genetic diagnosis (PGD), is used to identify embryos with recessive or dominant genetic defects. These conditions are most commonly found in patients who have a known family history of a specific inheritable disease or disorder. PGT-M is useful for preventing these conditions from being passed down to a baby. There are many disorders that can be tested for using PGT-M, including:
- Cystic fibrosis
- Fragile X syndrome
- Muscular dystrophy
- Spinal muscular atrophy
- Tay-Sachs disease
Preimplantation Genetic Testing for Structural Chromosomal Rearrangements (PGT-SR)
PGT-SR is used to test for chromosomal translocations, which is a type of abnormality in which chromosome fragments detach from the main structure and rearrange either on a different chromosome or within itself. The number of chromosomes remains unchanged, but their structural integrity can be compromised, resulting in genetic disorders. There are two types of chromosomal translocations:
- Balanced translocations, also known as reciprocal translocations, occur when chromosomes mutually exchange pieces of each other, resulting in no gain or loss of material.
- Unbalanced translocations, also known as non-reciprocal translocation, occur when one chromosome transfers its materials to another chromosome without receiving any material in exchange, resulting in a disproportionate amount of material. This can cause genetic defects.