Chorionic villus sampling is an invasive examination in which villus fragments are aspirated with a hollow needle from the placenta. The egg skin is not affected, so that no fluid can escape here. Since there are not only fetal cells (cells from the child) in the placenta, a comparative blood sample is also taken from the pregnant woman, so that the human geneticist can later safely differentiate the cells of the child from those of the mother. The complete set of chromosomes is examined in terms of their number and structure. A rapid test shows usually after only one day, sometimes even of the day of the puncture a result, for the most common chromosome disorders. The final result, however, takes 1 to 2 weeks depending on the quantity and quality of the material.
This examination has an extreme low risk of abortion (risk of losing your child after the procedure) if it is carried out by an experienced examiner. The professional association of established prenatal diagnosticians titled it with approx. 1: infinite, i.e. almost 0, which differs greatly form the numbers distributed in Internet forums. There is an urgent need for clarification here. The risks of invasive diagnostics communicated in the information sheets and in the guidelines date from the late 80s and 90s. Factually, against the background of a modern understanding of puncture and a modern puncture technique in the hands of specialists, it is no longer correct. (www.bvnp.de)