Sample of chorionic villi

Chorionic biopsy or chorionic biopsy (less known as a chorionic villus sample) is a prenatal diagnostic procedure to determine if chromosomopathies exist in the embryo. It consists of the extraction of a small piece of chorion (chorionic villi) and its analysis by means of FISH (fluorescence in situ hybridization) or PCR (polymerase chain reaction) techniques. It is usually done in the weeks 10-12 of pregnancy, and this is its great advantage with respect to amniocentesis, which takes place from week 15. Process

It takes 10 to 20 minutes to complete. A small sample of the chorion (the external tissue surrounding the fetus and placenta) is taken and analyzed. Using ultrasound to guide the probe, a thin, hollow tube is inserted into the vagina or abdominal wall, into the uterus, and several chorionic cells, identical to those of the fetus, are removed. Analysis of these cells provides a "window" to see the fetus.

Occasionally the amniotic sac can be perforated and produce infection and bleeding. Even so, it appears that the risk of miscarriage only increases by 1%.

This test can be performed before amniocentesis and the results are obtained in about two or three weeks. Therefore, it allows women to make a decision about the possibility of abortion earlier, by week 15, after which amniocentesis can be performed.

wiki