How Preimplantation Genetic Diagnosis Can Help You Conceive
Preimplantation genetic diagnosis and preimplantation genetic screening, also referred to as PGD and PGS respectively, provide important analysis of genetic errors within the embryo that can negatively impact the success rate of your in vitro fertilization (IVF) treatment. Dr. Ali R. Guerami and our team use advanced technology and techniques at our Dallas, TX, clinic to provide these services to help you build your family. If you have a family history of certain genetic disorders or medical conditions that you are concerned may be passed on to your future children, this genetic testing can help you find early answers to better prepare for your future.
What are PGD and PGS?
Preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) are two different forms of genetic testing that can be performed on embryos as part of the IVF procedure. Before the embryo transfer, our embryologist can use state-of-the-art technology to identify certain genetic and chromosomal disorders. PGD and PGS can also isolate the healthy embryo to increase your chances for a successful implantation.
Although often used in combination, each test is used to identify different disorders. PGD is used to detect specific gene mutations known for causing Cystic fibrosis, muscular dystrophy, and even ovarian and breast cancers. PGS is used for identifying chromosomal disorders known for causing Down syndrome, Edwards syndrome, Turner syndrome, and other birth defects. Each of these conditions, caused by a single gene defect, can be genetically passed on and cause IVF failure or miscarriage.
Candidates for Each Test
PGD is recommended for couples who have a family history of specific genetic disorders that could place their future children at risk. Even if the mother is not a direct carrier of the genetic mutation, it can still be passed on to the embryo from the father’s side. PGD can test for:
- Cystic fibrosis
- Sickle cell anemia
- Muscular dystrophy
- Huntington’s disease
- Tay-Sachs disease
- Fragile-X syndrome.
- Breast and ovarian cancer (BRCA1 and BRCA 2 mutations)
PGS is recommended for patients who have a family history of chromosomal defects and have experienced at least two miscarriages. It is also beneficial for patients who have:
- Been diagnosed with unexplained infertility
- Experienced IVF failure
- A family history of children with genetic defects
- Had a pregnancy with a chromosomal defect
- Been diagnosed with chromosome translocations
Because embryo chromosomal defects have a greater chance of forming from women of advanced maternal age, women over the age of 35 are encouraged to undergo PGS.
How the Testing is Performed
Once the egg is fertilized as part of the IVF procedure, it begins to develop into an embryo. At the blastocyst stage, around day five of fertilization, the embryo has developed fetal tissue and TE (trophectoderm) cells. During a biopsy, the embryologist uses a specialized needle to remove three to five TE cells from within the embryo. The cells are then placed inside a small tube and carefully analyzed using advanced technology.
During this stage, the embryologist uses polymerase chain reaction (PCR) to amplify the DNA within the extracted cells to identify certain genetic and chromosomal abnormalities by comparing it to genetic markers within a healthy embryo. Each embryo undergoes the same testing to make sure that the healthiest embryos are chosen for implantation.
With these advanced tests, you can face less of a risk of IVF failure and increased likelihood of successful conception.
While the cells are undergoing genetic testing, the remaining embryos will be frozen. Testing generally takes two to three days before results are available. Once the healthy embryos have been identified, your IVF procedure will be completed with a frozen embryo transfer cycle. With these advanced tests, you can face less of a risk of IVF failure and increased likelihood of successful conception.
Plan for Your Healthy Family
Dr. Guerami has over four decades of experience and is double board certified as a reproductive endocrinologist and infertility specialist. He works closely with our highly trained embryologist and genetic testing lab to deliver patients with the highest level of care. To learn more about preimplantation genetic testing and how it can improve the success rate of IVF, contact our office online today to schedule your consultation.
“Helping patients build a family is my passion. I am completely invested in your treatment and will apply my full knowledge and abilities to achieve your goals.” Dr. Guerami