Chorionic villus sampling

Chorionic villus sampling (CVS) is a form of prenatal diagnosis to determine chromosomal or genetic disorders in the fetus. It entails sampling of the chorionic villus (placental tissue) and testing it for chromosomal abnormalities, usually with karyotyping. The technique was first described in 1983 by Italian biologist Giuseppe Simoni.

Procedure

The procedure is usually carried out between the 11th and 14th week of pregnancy. It may be performed earlier, but this may increase the risk of complications. The sample is obtained in one of two ways: transabdominally or transcervically.

Transabdominal

In the transabdominal procedure, a needle is inserted through the mother's abdomen. The needle is guided into place with the help of ultrasound.

Transcervical

In the transcervical procedure, a thin plastic tube is passed through the cervix to the placenta, guided by ultrasound. The tube is used to gently suction off a small sample of chorionic villi.

Risks

The risk of miscarriage as a result of CVS is generally considered to be less than 1%. However, the risk may be higher if the procedure is performed before the 10th week of pregnancy.

Benefits

The main benefit of CVS is that it can provide early information about potential genetic conditions, allowing parents and doctors to make informed decisions about the pregnancy.

See also

• Amniocentesis
• Prenatal testing
• Genetic testing