Pregnancy and Chorionic Villus Sampling
How Is the CVS Test Performed?
Before undergoing a CVS prenatal test, appropriate genetic counseling, including a detailed discussion regarding the risks and benefits of the procedure, are recommended.
At the time of initial consultation and counseling, an ultrasound exam will be performed to confirm gestational age (the development stage of the embryo) and the location of the placenta. This is done so that CVS can be performed at the appropriate gestational age (which is usually 10 to 12 weeks from the woman's last menstrual period).
There are two ways to collect chorionic villi from the placenta: through the vagina or through the abdomen.
To collect cells through the vagina, a speculum is inserted (in the same way as a Pap test). Then a very thin, plastic tube is inserted up the vagina and into the cervix. Using ultrasound images, the tube is guided up to the placenta, where a small sample is removed.
To collect cells through the abdomen, a slender needle is inserted through the woman's abdomen to the placenta, much like in amniocentesis.
The sample of chorionic villi is then sent to a lab, where the cells are grown in a special fluid and tested a few days later. Culture results will be available within two weeks. Your doctor will notify you of the results.
Will the CVS Test Be Painful?
It could be, but it's over relatively quickly. The test takes no longer than a half hour from start to finish. The extraction itself runs only a few minutes.
What Happens After the CVS Test?
You'll need to take it easy immediately after a CVS test, so arrange for someone to drive you home. For the rest of the day, you'll need to rest. Generally, women are advised to abstain from strenuous physical activity, sex, and exercise for three days following the procedure. You may have some cramping and bleeding, which is normal, but do tell your doctor or midwife. If you notice fluid leaking from your vagina, call your health care provider immediately.