Structural and number disorders in the genes or chromosomes in the structure of DNA carrying genetic information can cause genetic diseases. Genetic diseases are examined in three main groups as chromosomal disorders, multifactorial polygenic diseases and single gene diseases.

The process of examining embryos in terms of genetics and chromosomes before they are placed in the womb of the expectant mother is called PGD, that is, pre-implantation genetic diagnosis. However, this method has started to leave its place to the Comprehensive Chromosome Scan method today. It is important to evaluate the chromosomes in terms of structure and number before in vitro fertilization, as there may be situations such as no pregnancy or miscarriage even if it occurs due to chromosomal anomalies in women aged 38 and over.

Preimplantation Genetic Diagnosis (PGD)

PGD is a common method that can be applied in many centers. Although it has effective results, it is known that it is not fully sufficient. The PGD method, which enables embryos to be examined only from certain angles, cannot fully identify genetic disorders that cannot result in live birth. Detection of chromosomal disorders between 60% and 80% and the uncertainty of the remaining 40%-20% are seen as the shortcomings of the PGD method. The PGD method can be applied in various situations such as HLA-matched siblings, advanced age pregnancy request, couples with structural chromosome disorder, having family members with X-linked genetic diseases, recurrent pregnancy losses and recurrent IVF treatment failure.

Comprehensive Chromosome Scan

It can be defined as a method applied before IVF treatments and without transferring embryos to the mother’s womb. In this method, all available chromosomes can be searched. In the method also referred to as Array Comparative Genomic Hybridization (aCGH), chromosomal maps of the examined embryos can be obtained, and thus the transfer of unhealthy embryos can be prevented, as chromosomal disorders that could not have been noticed before can be detected. In the technique, it can be tested whether each of the embryos has 46 chromosomes, 23 from the mother and father. Afterwards, the embryos are stored for 1-2 months to wait for the mother’s hormone balance to be restored. This method is applied to expectant mothers over the age of 38, those who have failed in vitro fertilization treatment before, and those who experience recurrent pregnancy loss.