At the TruCare Fertility Clinic, Lagos, we understand that reproduction is a sensitive and personal issue. We are committed to providing sophisticated testing services to facilitate having a healthy child. Preimplantation Genetic Diagnosis (PGD) procedure identifies whether an embryo has inherited a known genetic abnormality from a parent.
What is Preimplantation Genetic Diagnosis (PGD)?
PGD is a technique that assists couples, with a known inherited condition in their family, to avoid passing it on to their children. PGD is used when one or both parents has a known genetic abnormality and diagnostic testing is performed to determine if the embryo has also inherited the abnormality.
The procedure is performed before implantation thus allowing the couple to decide if they wish to continue attempting to conceive with the pregnancy. PGD can test for more than 100 different genetic conditions.
- First, a couple/few cells are microsurgically removed from the embryos, which are about 5 days developed. After this cell collection, the embryos are safely frozen.
- The DNA of the cells is then evaluated to determine if the inheritance of a problematic gene is present in each embryo. This process takes at least one full week.
- Once PGD has identified embryos free of genetic problems, the embryo(s) will be placed in the uterus (usually by an IVF procedure), and the wait for implantation and a positive pregnancy test begins.
- Any additional embryos that are free of genetic problems are kept frozen for possible later use while embryos with the problematic gene(s) are destroyed. This testing process may take weeks.
Concerns of PGD
- Many people believe that because life begins at conception, the destruction of an embryo is the destruction of a person.
- While PGD helps reduce the chances of conceiving a child with a genetic disorder, it cannot completely eliminate this risk. In some cases, further testing is needed during pregnancy to ascertain if a genetic factor is still possible.
- Although genetically present, some diseases only generate symptoms when carriers reach middle age. The probability of disorder development should be a topic of discussion with the healthcare provider.
- Keep in mind that preimplantation genetic diagnosis does not replace the recommendation for prenatal testing.
Who should consider PGD?
PGD may be considered in all IVF cycles; however, those who might benefit most from this test are couples at increased risk for chromosome abnormalities or specific genetic diseases.
This includes women who have had several miscarriages, or who have had a prior pregnancy with a chromosome abnormality. Women over 38 years of age and men with some types of sperm abnormalities may also produce embryos with higher rates of chromosome abnormalities.
In addition, if a person carries a rearrangement of the chromosomes, PGD can identify which embryos have a normal amount of chromosomal material. When there is a 25% or 50% chance to have a child affected with a specific genetic disease, PGD can be designed to identify which embryos are affected, unaffected, or a carrier (if applicable) for that disease. Then, only embryos without the disease are transferred to the uterus to attempt pregnancy.