- MEDICINE ATHENS MED4WOMAN ATHENS
- MEDICINE VOLOS MED4WOMAN VOLOS
- 2103390838
- 2421022988
Obstetrician Gynaecologist
Doctor of Medicine, University of Athens Medical School
Panagiotis Polyzos, Gynaecologist Obstetrician, is active at the Institute of Life - IVF Unit of Iaso Maternity Hospital.
The chorionic villi consist of the cells that will form the placenta during pregnancy.
Chorionic Villus Sampling (CVS) involves examining these structures — the chorionic villi. Since both the fetus and the placenta originate from the same initial cell (the fertilized egg), their genetic material is identical.
It is performed from the 11th to the 14th week of pregnancy.
CVS is not scheduled earlier, because according to some studies, when performed before 10 weeks, there is a small risk of abnormalities in the fetal fingers and limbs.
Chorionic villus sampling is recommended: a) In cases of hereditary genetic disorders (e.g., thalassemia, cystic fibrosis, etc.). b) In advanced maternal reproductive age. c) When there is an increased probability of Down syndrome (Trisomy 21) or other chromosomal abnormalities, after the corresponding prenatal screening. d) In the presence of a relevant medical history in a previous pregnancy.
First, the position of the placenta and the fetus is checked by ultrasound. The appropriate area of the abdomen is disinfected, and local anesthesia is administered. Then, a thin needle is passed through the mother’s abdomen, and a sample of chorionic villi is aspirated, always under continuous ultrasound guidance.
The procedure lasts about 1 minute and is almost painless. Afterwards, the normal fetal heart rate is confirmed, and the pregnant woman can leave.
During the first two days, some symptoms may occur. However, in almost all cases, the pregnancy continues without problems. The pregnant woman may notice some abdominal discomfort, period-like pain, or light bleeding. It is therefore recommended to rest during this period and avoid any physical exertion.
A simple painkiller such as paracetamol can be used safely.
Rarely, within the following five days, signs of infection may appear, such as fever, heavy bleeding, or severe pain. In this case, the pregnant woman should contact her physician immediately.
Rarely, the results may be unclear due to inadequate sampling or contamination with maternal cells. In such cases, the procedure needs to be repeated.
Additionally, if mosaicism is identified in the examination result, amniocentesis must be performed later.
The risk of miscarriage due to CVS is approximately 0.25–0.5%, almost the same as that of amniocentesis at 16 weeks. If such a complication were to occur, it would happen within the following five days.
If the pregnant woman’s blood type is Rh-negative, a specific anti-D immunoglobulin is administered intramuscularly to prevent sensitization of the immune system.
The initial results for Down syndrome and other chromosomal abnormalities are usually available within 2–3 days, and the final results within 2 weeks. For rarer genetic conditions, approximately 2 weeks are required.
