Everything we need to know about Preimplantation Genetic Testing

Chemist in the lab checking with ph strips

Success in IVF can be increased through preimplantation genetic testing of fetal chromosomes, which resulted from IVF before embryo transfer.

The test has been used successfully for the past 20 years, helping thousands of couples not only have the child they so desire, but also ensure that it is perfectly healthy.

With preimplantation genetic diagnosis we increase the chances of successful IVF as we make a careful selection of the highest quality eggs, which significantly increases the chances of conception.

Pre-implantation examination is considered necessary for couples:

1) Parents of carriers of balanced permutation or some other chromosomal abnormality.

2) Women of advanced reproductive age -over 38 years- who undergo the procedure of in vitro fertilization.

3) Couples who have a history of multiple miscarriages of unknown cause during the first trimester of pregnancy.

4) Couples with a history of multiple failed IVF cycles.

The preimplantation diagnosis is made by biopsy of 1-2 cells from the embryo at the stage of 8 cells, ie the embryo of the 3rd day which is then cultured by specialists in the laboratory.

At this stage the 8 fetal cells contain exactly the same genetic material. Then one or 2 cells are removed for biopsy and the remaining 6 or 7 continue to grow normally.

At this stage the embryonic cells are multiplicative, so there is no problem with removing 1-2 cells from the embryo, the rest are able to grow into a perfectly healthy embryo.

The biopsy requires the use of molecular biology techniques, which is why preimplantation diagnosis has a high cost.

During the analysis, the embryo undergoing the biopsy continues to grow normally in the laboratory and to grow (the number of cells increases) towards the blastocyst stage.

After the biopsy, a genetic test of the material that has been removed from the fetus follows.

The two most commonly used methods are Polymerase Chain Reaction (PCR) and Fluorescent In Situ Hybridization (FISH).

PCR is a technique in which part of the DNA containing the gene to be tested is amplified and in this way its presence in the cell and consequently in the fetus itself can be more safely checked.

FISH analysis involves hybridization of the chromosomes in question with the parallel use of labeled DNA probes, thus achieving the detection of chromosomal abnormalities.

Once the analysis stage is completed, healthy embryos are selected and transferred during embryo transfer.

Preimplantation genetic testing is a modern and safe method that is applied with great success in many parts of the world, having helped thousands of selected couples to have children and make their dream come true.