Chorionic villus sampling (CVS) is a procedure that is carried out during early pregnancy. Usually the reason is to see if the developing baby has a chromosomal disorder such as Down's syndrome or a genetic disorder. It is not a standard test done in pregnancy, but is usually offered to women in whom screening tests suggest there may be a higher chance of a baby with Down's syndrome.
This is a companion discussion topic for the original article at https://patient.info/pregnancy/pregnancy-screening-tests/chorionic-villus-sampling-cvs