VILLOCENTESI: THE RISKS, THE COST, AND WHEN TO DO IT

CVS, or chorionic villus sampling, is the earliest of prenatal diagnoses. It consists in the aspiration and analysis of a small amount of chorionic tissue, a component of the placenta. The sample is used to understand and predict any genetic or chromosomal diseases of the fetus.

When is it done, and why?

The examination of the chorionic villi is used to evaluate the karyotype, that is, the fetal chromosomal structure, in order to evaluate its normality or, on the contrary, the presence of anomalies. CVS is the test of choice to recognize chromosome or gene diseases within the first 3 months of pregnancy. The test is carried out between the eleventh and thirteenth week of gestation. It is proposed to patients judged to be at high risk of chromosomal abnormalities, for example: women over the age of 35, women with increased thickness of the nape of the neck, mothers with a previous child affected by a chromosomal abnormality, parents with chromosomal alterations. It is therefore advisable if the couple is at high risk for these diseases (previous children or affected family members, advanced maternal age, etc.) or if the fetus after ultrasound (nuchal translucency) and the bi-test, is positive at screening (therefore at "high" risk of chromosomal abnormalities).

Villocentesis: the results and how to read them

Preliminary information is available 2 or 3 days after CVS, while for the definitive report it is necessary to wait 10-15 days. The different waiting times reflect two different analytical techniques of the placental sample, which where possible are always performed jointly. Chromosomal analysis must be performed on dividing cells and, in the case of chorionic villi, two methods of investigation are used: the direct method for early diagnosis and cell culture to optimize diagnostic reliability. After sampling by CVS, the sample is divided into two parts: one is used for direct analysis, the other for post-culture analysis. With the direct method, each of these cells, dividing several times, gives rise to daughter cells with the same chromosomal makeup. With the culture method, the cells are seeded on a special slide and incubated, in order to favor their multiplication and originate the relative colonies. After a few days, when the colonies are sufficiently numerous, the chromosome examination is performed.

The risks of villocentesis

The most feared main risk of a villocentesis is "abortion. The incidence of cases is very low, however, it is sufficient to rely on a recognized and trusted structure. As for other possible risks for the fetus, there is that, also with a low incidence, of malformations due to a too early chorionic villus sampling, when embryogenesis has not yet been completed. However, medical specialists proceed with great caution, knowing these risks. For the mother, the main risks are those of discharge, uterine contractions or infections of the uterus.However, the risk percentages in all these cases are always very low.

The cost

As for the costs of amniocentesis, CVS is also free in public facilities, especially in the presence of certain risk factors such as a pregnancy over 35 years, a family history of chromosomal or genetic diseases or other risk factors. the ultrasound shows a certain percentage of risk of malformations, the mother is exempt from paying the ticket for the villocentesis. If it is carried out privately, the villocentesis costs, according to the structures, from 800 to 1,700 euros.

Amniocentesis and villocentesis: the video to know when to do them

In this video, Dr. De Mita explains what amniocentesis and CVS are, and when each of these tests should be done. Villocentesis is the earliest analysis, it is not always done, but in case of particular risk conditions it is decided to perform it between the 11th and 13th week of gestation. Amniocentesis is performed between the 15th and 17th. Find out everything there is to know about these two prenatal diagnoses.