Division Of Medical Genetics, Department Of Human Genet (2002). "About Chorionic Villus Sampling." Emory University School of Medicine. Retrieved March 1, 2008, from http://www.genetics.emory.edu

The process of chorionic villus sampling is described in full detail. Ultrasound is used as a guide to locate the placenta where the best sample may be taken. A thin catheter is inserted through the cervix into the uterus in order to extract the tissue sample. This process takes about two to three minutes with only mild discomfort.