Chorionic villus sampling (CVS) is done to identify chromosomal or genetic disorders in the fetus. CVS is a prenatal test in which a sample of chorionic villi is removed from the placenta for testing. This test may be recommended by your health care provider when your baby has a higher risk of some birth defects. That is in case if you or your partner has family medical history that reveal potential risks or if you are over 35 year.
What Does The Chorionic Villus Sampling (CVS) Test Look For?
CVS can help in ruling out some birth defects, such as Down syndrome, cystic fibrosis, sickle cell anemia, and others but it can not detect neural tube defects, such as spina bifida.
Chorionic villus sampling also provides access to DNA for paternity testing prior to delivery. DNA is collected from the potential father and is compared to DNA obtained from the baby during chorionic villus sampling. The results are accurate (99%) for determining paternity.
When Is Chorionic Villus Sampling (CVS) Performed?
CVS usually takes place at 10–12 weeks’ of gestation. CVS may be chosen over amniocentesis because it may be performed earlier in the pregnancy.
How Is The Chorionic Villus Sampling (CVS) Performed?
The sample can be taken through the cervix (transcervical) or the abdominal wall (transabdominal).
In transcervical, a thin catheter is placed through the cervix and in transabdominal, long thin needle placed through the abdomen to your placenta The chorionic villi cells are gently suctioned. Transcervical is the most common method.
The CVS procedure collects larger samples and provides faster results than amniocentesis. Results may be received between one to seven days.
What to Know About CVS test Results?
CVS is a diagnostic test that detects chromosome abnormalities and genetic disorders with high levels of accuracy (98-99%). You should get test results in about one week. CVS is very accurate. If your baby does have a problem, you can meet with a genetic counselor and talk about your options.
What Are The Risks And Side Effects of CVS To The Mother Or Baby?
CVS is relatively safe. But it is an invasive procedure, and it poses a risk of miscarriage slightly higher than amniocentesis. It also poses a small risk of complications in your baby, such as loss of limbs. Talk to your doctor about the risks. Make sure the test is done by doctor who has a lot of experience doing CVS.
CVS is not recommended for women who:
- Have an active infection (i.e. STD)
- Are carrying twins
- Have experienced vaginal bleeding during pregnancy.
You should also contact your healthcare provider if you experience fever, Chills, Leaking of amniotic fluid.
Tests Similar to This One
Amniocentesis, karyotype test, FISH test, microarray analysis
Compiled using information from the following sources: 1. Mayo Clinic Complete Book of Pregnancy & Baby’s First Year. Johnson, Robert V., M.D., et al, Ch. 11.