| Article Index |
|---|
| PGS |
| What causes disorders |
| What genetic material is tested |
| Genetics Lab |
| Indications for PGS and Diagnosis |
| Prepare for PGS or PGD |
| All Pages |
Preimplantation Genetic Screening and Diagnosis
Testing embryos in the IVF lab for genetic abnormalities before they are transferred back to the uterus (preimplantation) has been possible since 1989. Preimplantation genetic testing is a diagnostic test used in conjunction with in vitro fertilization (IVF) and is performed on embryos to assist detection of known genetic diseases or chromosomal abnormalities.
When the testing is searching for a specific genetic disease known to be present in a family, the test is called Preimplantation Genetic Diagnosis (PGD). When the testing is searching for a number of possible genetic problems that might be present, the test is called Preimplantation Genetic Screening (PGS).
Please note: PGD and PGS do not screen for all potential genetic diseases and cannot guarantee a healthy child.
Overview
The basic concept of preimplantation genetic testing is simple. Each embryo is analyzed for a specific kind of abnormality through a specific genetic test. This information is used to identify embryos that are normal. Then the doctors select the healthiest embryos to be placed back in the uterus. By utilizing the normal embryos, the probability that couples will have a healthy child increases.
Steps for IVF and genetic testing of embryos
- Medication is used to stimulate the production of multiple eggs.
- Eggs are recovered through a minor operation performed under anesthesia using ultrasound guidance.
- Eggs are fertilized with sperm in the IVF laboratory and allowed to grow. Most often, IntraCytoplasmic Sperm Injection (ICSI) is required.
- Part of the genetic material of the egg or one to several cells from the embryo are removed and submitted to a specialty genetics lab for testing.
- The test results can take anywhere from 36 hours to a few weeks.
- Normal embryos are transferred to the woman’s uterus either a few days after the biopsy or in the next month in a new cycle if the testing requires a longer time.
While the concept seems straightforward, the application of this technology has been more complex and the benefits variable. When first introduced, Preimplantation Genetic testing was hoped to become a major advance in IVF. While Preimplantation Genetic Diagnosis has fulfilled the expectations to help reduce the risk of having a child born with a family-related genetic problem, Preimplantation Genetic Screening has not resulted in as great of benefits.
What Causes Genetic Disorders?
