Chorionic villus sampling

Chorionic villus sampling (CVS) is a procedure used to detect genetic abnormalities in the fetus (baby). The procedure is much like an amniocentesis except a tiny sample of the placenta is obtained for the study instead of amniotic fluid. CVS is performed between weeks 10 and 14 of pregnancy which is five to six weeks earlier than amniocentesis. Thus, CVS can be used to determine genetic anomalies earlier in pregnancy than an amniocentesis can. Complications from this procedure are less than 1%.