Preimplantation Genetic Diagnosis, in an abbreviation form ‘PGD’, as the name suggests, is a laboratory technique or better say, a reproductive procedure that works with In Vitro Fertilization (IVF) to minimize the risk of transmitting inherited diseases and failures. To those who are interested in having IVF in Iran, PGD is a necessary service that Iranian clinics and hospitals will provide patients. In the further explanation of this test, it is stated: This is a genetic test that diagnoses embryos, detects diseases or any unhealthy conditions such as inherited conditions, and gives parents a healthy pregnancy.
PGD, along with PGS, is one of the main tests of PGT; preimplantation genetic testing. People who use IVF to treat their fertility issues must be aware that PGD will be a complementary test to ensure the health of their fetuses. In the following, you will read more about PGD, how it works, the best candidates, etc.
What Are PGD Uses?
As mentioned before, PGD is a genetic test that advanced clinics use to diagnose any embryo’s diseases and choose the healthiest embryo to transfer into the uterus. It means you can consider PGD as a plus for those who are having IVF as a treatment for their infertility problems. PGD also will be considered by doctors when someone in a family may need a bone marrow donor having a child who can process matched stem cells. Generally, those who need PGD to diagnose hereditary diseases and reduce the risk of disease transmission to their fetuses are not necessarily infertile. But those who are involved with infertility problems may also have a history of hereditary disease in the family, and PGD will help them here and will prevent their embryos from receiving any hereditary disease.
According to this, PGD is a beneficial laboratory technique that is widely used and equipped clinics use it in the cycle of IVF for infertile patients.
How Does PGD Work?
Although the results of a PGD test may take several months to complete before starting an IVF cycle, PGD will be available for almost all hereditary diseases for which the mutation is known, and this test must be performed individually for each couple. In the IVF process, several retrieved eggs are inseminated with a single sperm. The embryos obtained from this inoculation grow in the culture medium until the stage of six to eight cells, which is the third day of the process. The embryo will be biopsied at this stage by removing one to two cells. This process will not cause any harm to the remaining cells.
Isolated cells are selected and evaluated for specific genetic assays. Among these, the embryos that have not been affected in any way will be transferred back to the woman’s uterus on the fifth day of the embryo’s development. Below, you will read about two main techniques used for genetic evaluation.
Polymerase chain reaction (PCR)
In the PCR test, the amplification process makes several copies of the specified gene. This amplification process opens the way for diagnosing very small amounts of DNA.
Fluorescent in situ hybridization (FISH)
This test is mostly used for the possibility of an abnormality in the number of chromosomes, such as Down syndrome, or any translocations such as defection of the structure of the chromosomes, and its function is to allow the laboratory to count the number of chromosomes in an isolated cell.
Infertile patients who want to have IVF in Iran should know that at MOM infertility treatment hospital, the embryology laboratory staff of this hospital have extensive experience in embryo micromanipulation and biopsy. The hospital’s genetic consultant is available to coordinate your cycle with the IVF team and PGD lab to make the process as smooth as possible.
Who Should Consider PGD?
PGD may be recommended by most specialists and in all conditions and stages of IVF. But those who will necessarily benefit from this test are couples who are at increased risk of genetic disorders such as chromosomal abnormalities. It means those who have had a pregnancy with a chromosomal abnormality in the past or suffered from several unsuccessful pregnancies, such as a miscarriage.
Women who are 38 years of age or older and men whose sperm may have abnormalities may produce fetuses with a higher rate of chromosomal abnormalities.
Additionally, if individuals carry a rearrangement or translocation in their chromosomes, the PGD test can identify which embryos carry normal amounts of chromosomal material. As mentioned earlier, this technology is considered a sub-branch of the same PGT-SR or structural rearrangement.
PGD is designed to identify affected or carrier embryos when there is a 25% or 50% chance that the child will have a specific genetic disease. Finally, only healthy and disease-free embryos are transferred to the uterus to attempt pregnancy. This type of testing process is also known as PGT-M (monogenetic disorders).
Is PGD Harmful to Embryo?
In the biopsy process, the specialist removes the cells of each embryo to perform PGD, which provides a very low possibility of harming the embryo. Also, when embryos must first be frozen for PGD, they must also undergo a thawing process before transfer. As we said before, for those patients who intend to have IVF in Iran, MOM infertility treatment center gives this commitment to the patients that by using the latest possible equipment, the least possible damage will be done to the embryo in any situation, and the doctors do their bests to reduce this damage to zero.
Because PGD examines the embryo in every way and detects any underlying or hereditary diseases, and since it is also an expensive process, not including the cost of IVF, PGD costs between $6,000 and $12,000 in developed countries.
However, this price will fluctuate greatly depending on your chosen fertility clinic. Patients who choose IVF in Iran should know that in MOM infertility treatment center, with the experience and pride of having a high success rate in recent years, the PGD test costs about $1,500 for up to eight embryos. Those parents who wish to try PGD on more than eight embryos can do so for an additional $200 to $250 per embryo.
PGD Steps During IVF Cycle
After the embryos are formed in the laboratory, they grow for five to six days. On day five or day six, a biopsy for PGD is performed on all properly developing embryos. For those who do not know how a biopsy happens, a biopsy is the removal of a few cells from the trophectoderm or the cell layer that is removed from the embryo at this stage of development. While the genetic material inside the removed cells is tested for abnormalities, embryos are also stored.
An IVF specialist will discuss the results of the PGD test with the couple and plan a frozen embryo transfer (FET) cycle to use the embryo(s). The medical team will decide to select the right embryo for transfer to the uterus with advice.
Where Does the PGD Testing Occur?
Preimplantation genetic diagnosis aka PGD is a procedure that occurs in advanced laboratories. Just to inform the patients who intend to have IVF in Iran, MOM infertility treatment center with the most updated and advanced laboratory is ready to provide patients with PGD along with IVF to bring the healthiest possible pregnancy for parents.