WHAT IS PREIMPLANTATION GENETIC DIAGNOSIS (PGD)?

Preimplantation Genetic Diagnosis (PGD) is a simple screening test carried out to determine if there are chromosomal or genetic disorders present in the embryos. This is performed through a procedure known as the IVF (in vitro fertilization). The embryos are first screened before being transferred directly into the uterus to enable a couple make a decisions on their next step on the IVF process. The embryos unaffected by the chromosomal or genetic disorders are selected to be used in the transfer process.

How Is PGD Performed?

The Preimplantation Genetic Diagnosis starts with the usual process of in vitro fertilization which involves retrieval of eggs and fertilization in the laboratory. The Preimplantation Genetic Diagnosis will involve the following processes:

• First the doctor will remove one or two cells from the embryo
• These cells are then evaluated to identify if the inheritance of the defect gene is present in the embryo
• On performing the PGD procedure and identifying the perfect embryo, it is placed in the uterus, for implantation to take place.
• Other additional embryos that have no defect may be frozen to be used at a later date while the problematic embryos are destroyed.

Who can undergo Preimplantation Genetic Diagnosis?
For those couples undergoing the IVF process, PGD may be recommended for the following people:

• People with chromosomal disorders
• Those women aged 35 years and above
• Carriers of single gene disorders
• Women who experience recurrent loss of pregnancy
• Women who have had more than one fertility treatment failure

Further, PGD have been used in gender selection.

What are the Advantages of PGD?

Preimplantation Genetic Diagnosis have the following benefits.

• PGD procedure can be used to test more than 100 different genetic conditions
• This procedure can be performed before implantation takes place therefore, it allows a couple to make a decision on whether they wish to proceed with the pregnancy.
• The PGD technique enables the couples to have biological children.

What are the Cons of PGD?

Just like any other procedure, Preimplantation Genetic Diagnosis has its own shortcomings such as;

• Most people believe in the fact that life begins during conception, therefore destruction of an embryo is not allowed.
• Preimplantation GeneticDiagnosis does not replace any recommendation for prenatal testing.
• PGD is known to reduce the chances of getting a child with a genetic disorder. However, this procedure can eliminate this risk completely. For this reason, further testing is needed during the pregnancy to identify if a genetic factor can occur.

Can I see a genetic counselor before undergoing the PGD?
For those wishing to undergo this procedure, genetic counseling is a crucial procedure to determine whether PGD is the best option for any patient. Couples considering undergoing IVF and who feel that the child may inherit chromosomal or genetic disorder need to see a counselor and discuss the available options. The counselor will advise the patients on how bringing up a handicapped can affect the family

Does PGD replace prenatal testing?

No, PGD will not replace prenatal tests such as amniocentesis, or chorionic villus sampling. This procedure provides a diagnostic detail based on the nature of a single cell. For this reason, prenatal testing are considered important and remain the best standard of care.