Chorionic Villus Sampling: What It Is and What to Expect
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor provides Chorionic Villus Sampling?
A maternal-fetal medicine doctor , an obstetrician with extra training in high-risk pregnancies , usually performs this procedure. A trained obstetrician may do it in some hospitals. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Chorionic villus sampling, or CVS, is a prenatal test done during pregnancy. A doctor takes a tiny sample of tissue from the placenta. Because the placenta and baby come from the same starting cells, the tissue usually has the same genes as the baby. A lab studies the sample for certain genetic conditions.
Why a doctor might recommend it
Doctors usually suggest CVS when a screening test, ultrasound, or family history raises a concern about the baby's genes. It can find conditions such as Down syndrome and other chromosome conditions. CVS is done earlier than amniocentesis, and results come back sooner.
How to prepare
- Ask whether to drink water beforehand; a full bladder can help with ultrasound guidance.
- Arrange a ride home if you prefer.
- Make a list of questions about the test and results.
- Tell your doctor about bleeding, allergies, or medicines you take.
What happens during it
CVS is usually done between ten and thirteen weeks. Using ultrasound, the doctor guides a thin needle or tube to the placenta and takes the sample through the belly or the cervix. It takes only a few minutes, and the sample goes to a lab.
Recovery
Most people go home the same day and resume normal activities within a day. Mild cramping or light spotting is common. Your doctor may suggest avoiding heavy lifting, exercise, and sex for a day or two.
Risks and side effects
CVS is generally safe but carries a small risk of miscarriage, about one in a hundred or less at experienced centers. Cramping, spotting, or brief dizziness can occur. Rarely, infection happens, so call your doctor about fever, heavy bleeding, or strong cramping.
Who performs it
Maternal-fetal medicine specialists perform CVS most often because it requires special training and regular practice. Your pregnancy doctor will usually refer you to a center that does this test often. Genetic counselors are often part of the care team.
How a direct primary care or concierge doctor fits in
A direct primary care doctor, paid a flat monthly fee instead of billing insurance, or a concierge doctor, can be a helpful partner during pregnancy. They can answer questions about genetic testing and help you decide whether CVS makes sense. They do not perform CVS, so they would refer you to a maternal-fetal medicine specialist, then help you understand results and coordinate follow-up care.
Common questions
How is CVS different from amniocentesis?
CVS takes placental tissue and is done earlier, around ten to thirteen weeks. Amniocentesis takes fluid around the baby and is done later, after fifteen weeks. CVS gives results sooner but cannot detect some conditions amniocentesis can, such as neural tube defects.
Does chorionic villus sampling hurt?
Most people describe it as uncomfortable rather than painful , pressure, cramping, or a quick pinch that fades quickly.
How long do CVS results take?
Preliminary results often come back within a few days. Final results usually take one to two weeks.
Can CVS find every birth defect?
No. CVS looks at genes and chromosomes but cannot find every condition. Some birth defects, such as heart problems, are found later through ultrasound.
Sources
- MedlinePlus - Chorionic Villus Sampling (CVS)
- American College of Obstetricians and Gynecologists - Chorionic Villus Sampling
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
