Chorionic villi sampling (CVS)

Performed when you’re between 10 and 12 weeks pregnant, chorionic villi sampling (CVS) is a procedure used to obtain a sample that can be tested for Down syndrome and other chromosomal disorders, as well as certain genetic disorders such as cystic fibrosis and sickle cell disease, if your pregnancy is determined to be at risk for a genetic disorder. CVS can’t test for the 3-5% of birth defects that are everyone’s background risk. The procedure involves taking a small sample of tissue from the developing placenta.