NIPT EVOGEN basic, twins (aneuploidies of chromosomes 13, 18, 21)

Description

This prenatal test is designed to determine the quantitative representation of loci of the chromosomes under study in order to calculate the risk in a twin pregnancy of trisomy of chromosomes 21 (Down syndrome), 18 (Edwards syndrome), and 13 (Patau syndrome). This methodology uses direct analysis of cell-free fetal DNA in the blood of a pregnant woman. The data analysis also takes into account the maternal age and gestational age, which are indicated on the test referral form.

The test examines embryonic-placental cell-free DNA isolated from maternal plasma starting from 10 weeks of pregnancy. The study offers a personalized risk assessment, which indicates whether the child is at risk of developing a genetic disorder. The study allows certain disorders and syndromes to be suspected and, knowing about them, to provide timely treatment for the born child. It should be noted that this is a screening test, meaning a diagnosis cannot be made based on its results. It assesses the probability of chromosomal pathologies but does not allow them to be unequivocally diagnosed even when a high risk is detected. The result of this test is not a diagnosis, but only a statistical probability figure.

Prenatal genetic testing assesses the risk of chromosomal abnormalities. If there is a risk of disorders, one can be prepared for the diagnosis and arrange in advance for specialized support and medical care for the child. With the current capabilities of medicine, a fairly high quality of life is possible with many congenital pathologies.

Detection of an increased risk of malformations in the child is not a diagnosis. False-positive results are possible.

Limitations of the methodology:

- Aneuploidies of other autosomes (chromosomes) are not determined.
- Chromosomal abnormalities or chromosomal mosaicism in the mother.
- Abnormal parental karyotype.
- The limitations of whole-genome NIPT are polyploidies, translocations, microchromosomal abnormalities smaller than 7 million base pairs, as well as chromosomal abnormalities not validated by the technology manufacturer.
- Gestational age of less than 10 weeks at the time of blood collection for the study.
- Singleton pregnancy that started as a twin pregnancy ("vanishing twin").
- Blood transfusion within the last 3 months.
- Organ or bone marrow/stem cell transplantation in the past (in these cases, the risk of a false test result is increased).
- Presence of an oncological disease.
- The test does not determine sex chromosome aneuploidies.
- In case of overweight – in pregnant women with obesity, the concentration of the fetal DNA fraction is reduced due to the larger volume of circulating blood.
- In a twin pregnancy, obtaining information about sex aneuploidies and incidental findings is not possible; only the risk of common aneuploidies – trisomies of chromosomes 21, 18, and 13 – is assessed. If a Y chromosome is present, it can be assumed that one of the fetuses is male; in the absence of a Y chromosome, it is assumed that both fetuses are female.