Non-invasive prenatal diagnosis (NIPD) using a molecular genetic non-invasive test (NIPT). This NIPT, also called cell-free fetal DNA test (cffDNA-Test), enables a reliable assessment of the risks of frequent chromosome disorders in the fetus.
This test is based on the long-known fact that both maternal and fetal genetic material (cell-free DNA, cffDNA) are present in the mother’s blood. The genetic material of the fetus comes mainly from the placenta.
The blood test is subject to the provisions of the Genetic Diagnostics Act and may only be carried out in connection with genetic counselling or early ultrasound diagnostics. This fact can be easily understood, considering that a child with severe physical or mental malformations does not necessarily have a defect in the genetic information, rather physical malformations occur about ten times more often than genetic disorders (20% of them rare mutations, microdeletions, which are not all examined in the NIPT), so that the sole implementation of the NIPT without accompanying differentiated ultrasound or echocardiography weights you as parent in a false sense of security.
If there is an increased risk of a chromosome disorder (e.g. of the child’s mother age) or if the embryo/fetus appears unremarkable on ultrasound, the blood test can be carried out as a possible alternative to amniocentesis or chorionic villus biopsy.
If there are any abnormalities e.g. in the ETS (e.g. thickened neck transparency) a chorionic villus biopsy or amniocentesis must at least be recommended for further clarification. We are currently not discovering about 12-19% of conspicuous fetuses just by performing a NIPT. Http://bit.ly/2SF0gGX(obgyn.onlinelibrary.wiley.com).
The costs are currently borne by only a few health insurance companies.
It is very gratifying that the GBA has decided to assume the costs, if indicated, from the end of 2020 or in early 2021.
Test interpretation limitations
In the event of a conspicuous test result, prior to any consequences, a confirmation of the findings must be carried out by a puncture with extraction and isolation of the DNA from fetal cells.
In very rare cases there may be false positive or false negative results or no results at all. In the latter case, the test can be repeated, but this lengthens waiting for a result.
No structural changes to the chromosomes can be found, although e.g. there is a syndromic genetically determined disease. In these cases, for example, a piece of a chromosome is missing, a piece is surplus or was incorrectly inserted into the chromosome. So-called mosaics (the disorder is not present in all fetal cells) cannot be determined with certainty. In a mosaic, cells of a tissue or the entire organism of the embryo carry different genetic information.
In the meantime there are some companies that produce these tests at home and abroad and offer them through the genetic institutes and gynecological practices.
However, it is hardly apparent to the layperson which of the tests offered is the most suitable for you. Each company advertises something special in order to stand out from the competition. Some of it makes sense, others are not expedient and expensive in terms of what you want to know.
We see the problem and have made a sensible pre-selection of tests examined in Germany. We are constantly adapting this selection to reflect new scientific results. As part of the ETS, you will be informed about the possible NIPTs (e.g. Fetalis, Pränatest, Harmony, Panorama), depending on your pregnancy and family history.