Chorionic villus sampling (CVS) is a prenatal test used to detect genetic abnormalities in a developing fetus. It involves taking a small sample of tissue from the chorionic villi, which are tiny finger-like projections in the placenta. This procedure is typically performed between the 10th and 13th weeks of pregnancy and can provide results faster than other tests, such as amniocentesis. During CVS, a healthcare provider may use a thin tube inserted through the cervix or a needle inserted through the abdomen to collect the tissue sample. The sample is then analyzed for chromosomal conditions, such as Down syndrome or other genetic disorders, helping parents make informed decisions about their pregnancy.