Chorionic villus sampling (CVS) is a test some pregnant women have to screen their baby for genetic problems.
How the Test is Performed
CVS can be done through the cervix (transcervical) or through the belly (transabdominal). Miscarriage rates are slightly higher when the test is done through the cervix.
The transcervical procedure is performed by inserting a thin plastic tube through the vagina and cervix to reach the placenta. Your health care provider uses ultrasound images to help guide the tube into the best area for sampling, and then removes a small sample of chorionic villus (placental) tissue.
The transabdominal procedure is performed by inserting a needle through the abdomen and uterus and into the placenta. Ultrasound is used to help guide the needle, and a small amount of tissue is drawn into the syringe.
The sample is placed in a dish and evaluated in a laboratory. Test results take about 2 weeks.