Preimplantation genetic testing involves identifying genetic defects within embryos created by IVF. Genetic testing can help patients learn more about the health of their embryo(s) and their chances for a successful pregnancy.
The overwhelming majority of potential parents who have endured fertility challenges want to know why. If you and your partner have undergone fertility testing that didn’t provide conclusive answers, a diagnostic process called preimplantation genetic testing might help you better understand the reasons behind your difficulties.
What is PGT?
Preimplantation Genetic Testing works to improve embryo selection for transfer and diminish miscarriage rates by allowing your fertility doctor to determine the chromosome number of each embryo that makes it to the blastocyst stage.
PGT is a broad term that incorporates the more well-known functions of Preimplantation Genetic Diagnosis (PGD) and Preimplantation Genetic Screening (PGS).
Preimplantation genetic testing refers specifically to the three types of tests that can be performed on embryos during IVF.
These tests are:
- Preimplantation genetic screening for abnormal chromosome number (PGT-A)
- Preimplantation genetic testing for monogenic disease (PGT-M)
- Preimplantation genetic testing structural rearrangement (PGT-SR) for known chromosomal misarrangements including inversion and translocation
These tests serve two important purposes: the first is to learn whether embryos have genetic abnormalities that can cause failed implantation and miscarriage, ending in an unsuccessful IVF.
The second purpose is to identify those embryos with genetic defects that can end in a child with a genetic disorder that could cause death or serious conditions.
Understanding the results could dramatically reduce your risk of passing down severe medical disorders to your offspring. Parents whose fertility treatment solutions include in vitro fertilization (IVF) should learn how genetic testing could help lower the odds of a failed pregnancy.
Potential parents with a family history of certain disorders can benefit from screening for inherited conditions. This is known as preimplantation genetic diagnosis (PGD).
Preimplantation Genetic Diagnosis (PGD)
PGD is a specialized procedure that screens for a broad spectrum of abnormalities that could inhibit fetal gestation. The process also screens for inherited conditions that could lead to serious and potentially tragic medical issues.
With Preimplantation Genetic Diagnosis, embryos free of disease and genetic problems are implanted or frozen for later use. PGD can test for genetic disorders and can allow couples to have a healthy child.
PGD should be considered for:
- Women over 35
- Carriers of sex-linked genetic disorders, chromosomal disorders, or single-gene disorders
- Women who have suffered recurrent pregnancy loss
- Couples who have failed other fertility treatments
For potential parents who don’t have a family history of genetic disorders but who are nonetheless at higher risk for experiencing abnormalities during pregnancy, we encourage preimplantation genetic screening (PGS).
Preimplantation Genetic Screening (PGS)
Although PGD is a highly effective solution for identifying inherited medical anomalies, PGS offers parents the added security of identifying chromosome malformations that can lead to miscarriage or significant abnormalities in surviving children.
This procedure is highly recommended for women over the age of 44 when the percentage of embryos with chromosomal defects can be as high as 90%.
Many parents who have specific concerns about passing a dangerous genetic trait down to a child of particular sex opt for PGS because it is the only screening tool for selecting the child’s gender. Parents with a family history of disorders like Turner syndrome, Hunter syndrome, and Rett syndrome should seriously consider PGS in addition to PGD to minimize their child’s risk.
Genetic screening technology empowers parents with the tools they need to achieve healthy pregnancies. The fertility specialists at the Pacific Reproductive Center have helped hundreds of patients overcome their reproductive obstacles using leading-edge tools and resources designed to quickly and accurately identify deformities that lead to miscarriages or life-threatening conditions in surviving children.
Couples interested in preimplantation genetic testing should make an appointment. After the initial consultation, couples meet with a genetic counselor to discuss personal and family medical history. The doctor determines the risk for a genetic disorder and can then proceed with a blood draw from both partners, and a diagnostic protocol is put in place.