Early pregnancy loss is often an effect of embryo genetic abnormalities. These abnormalities may come from parents’ reproductive cells or from mutations occurring during divisions of embryo cells. In most cases, there are abnormalities in the number of chromosomes, so-called aneuploidies. They result in the development of Down, Turner, Klinefelter, Patau syndromes, among others. In the presence of genetic errors in a developing embryo, early pregnancy loss, death of the embryo/foetus or premature delivery occur in the vast majority of the cases.
Karyotype of a miscarried foetus
In case of a miscarriage happening at a hospital, it is recommended to collect material for further diagnostics. Due to a rapid response of a physician and medical team in such a case, it is possible to obtain much significant information. Confirmation of a chromosomal defect in a foetus/embryo in the miscarriage sample makes it easier for a physician to undertake appropriate diagnostic and therapeutic steps, especially in cases of recurrent miscarriages. When tests have been performed and a reason for abnormalities has been determined it is possible to provide genetic counselling combined with interpretation of a foetal karyotype what is significant for further pregnancies planned in the future. It may be possible to indicate whether further cytogenetic testing in parents is necessary even after one pregnancy loss.
Diagnostics of miscarriages is especially important in cases of women who have decided to become pregnant after the age of 35 years and in patients with habitual miscarriages (3 losses of pregnancy in the same couple).
Obtaining the result confirming the presence of genetic abnormalities in the miscarriage material is one of the indications for further diagnosis of potential parents, as well as for considering preimplantation testing. Specialist PGS and PGD diagnostics carried out as part of the in vitro programme allows for the analysis of the genetic material of the embryo, even before its transfer to a woman’s uterus. For many couples, this is the only chance for healthy offspring.
The NGS Technique
The INVICTA Genetic Laboratory was the first in the world to introduce the possibility of diagnosing genetic causes of miscarriage using the NGS (Next Generation Sequencing) technique. The iMGE Test™ (INVICTA Miscarriage Genetic Evaluation Test) detects each possible aneuploidy if a diagnosis of all chromosomes is applied. In this way, precise and reliable results can be obtained. So far, the diagnosis of the miscarriage material was based mainly on the classical karyotyping technique. It required establishing a culture of live cells from the collected sample before a test. Time and conditions of sample collection, as well its transport are factors making it difficult or sometimes even impossible to prepare results. The iMGE Test™ may be performed on fresh or fixed material – paraffin block. The second option makes it possible to perform the test even several years after loss of pregnancy.
What does the test consist in?
The first step is to collect a sample in a hospital. The doctor should prepare the preparation (tissue sample in saline or a paraffin block) and pass it to the lab. The iMGE Test™ applies special shipping kits that facilitate this process. When the sample arrives to the laboratory, it is pre-evaluated (macroscopically and microscopically) by a pathomorphologist. The specialist isolates the most valuable fragments and forwards them for further analysis. Then the material in the form of the so-called isolate gets to the laboratory of molecular biology, where DNA test is carried out using the NGS technique. In its framework, inter alia, the degree of potential contamination of the sample material with the maternal DNA, the so-called testing for MCC (Maternal Cell Contamination), is carried out. In most cases, if the supplied material has been collected correctly, despite the presence of some genes of a woman, it can be assessed accurately whether the miscarriage was caused by genetic factors. Sometimes it is necessary to sample also the maternal DNA.
As part of this test, the INVICTA Genetic Laboratory provides:
- Specialist Collection Kit
- Free transport
- Online access to the results