WellSpan Home

Health Library

Chorionic Villus Sampling

What is chorionic villus sampling (CVS)?

Chorionic villus sampling (CVS) is a test done early in a woman’s pregnancy. CVS checks for genetic problems in your baby. During CVS, your healthcare provider takes a small piece of tissue from the placenta for testing. The placenta is an organ that grows in the uterus during pregnancy. This tissue has the same genetic material as your baby. It can show if your baby is developing problems as it grows.

Why might I need chorionic villus sampling?

Women who have a higher risk or a family history of genetic problems may want to consider CVS testing. Your healthcare provider may recommend CVS if:

  • You are age 35 or older
  • You have a family history of a genetic disorder such as Down syndrome, Tay Sachs disease, or cystic fibrosis
  • You and your husband are carriers for genetic disorders
  • Blood tests or ultrasounds during pregnancy show that your unborn baby is at increased risk of having a genetic disorder

The results of CVS are usually available earlier in pregnancy, compared with some other genetic tests, such as amniocentesis. Amniocentesis uses a needle to get samples of amniotic fluid. But CVS is not as accurate as amniocentesis. Other first trimester screening tests provide similar information to CVS, and may be used instead of CVS.

What are the risks of chorionic villus sampling?

Talk about the risks and benefits of CVS with your healthcare provider. The risks of CVS include:

  • Miscarriage
  • Infection from the procedure, or passed from mother to baby

Another risk is fetal blood mixing with the mother’s blood. This may result in the mother's immune system destroying fetal blood. This problem is called Rh factor incompatibility. Mothers are given a medicine called Rh immunoglobulin after the procedure to prevent this from happening.

Some women may not be able to have CVS. For example, if you have a vaginal infection such as herpes or gonorrhea.  

How do I get ready for chorionic villus sampling?

CVS is usually done during the first trimester, after 10 weeks of pregnancy. Your healthcare provider will give you instructions. You will likely need a full bladder for the test. Drink plenty of water and don’t urinate before the test. You will also have an ultrasound before the test. This is a procedure that uses sound waves and a computer to make images on a screen.

What happens during chorionic villus sampling?

The test can be done through your belly (transabdominal). Or it may be done through your cervix (transcervical). It is common to feel some cramping during and after the CVS procedure.

For transcervical CVS

  • The healthcare provider moves a small tube (catheter) through your vagina and cervix to the uterus.
  • The provider uses ultrasound to guide the catheter into place near the placenta.
  • The provider takes a tissue sample using a tiny syringe at the end of the catheter.

For transabdominal CVS

  • The healthcare provider puts a needle through your belly (abdomen) and into the uterus.
  • The provider uses ultrasound to guide the needle into place near the placenta.
  • The provider takes a small amount of tissue with the syringe.

Women who are pregnant with several babies may need to have tissue taken from each placenta. But CVS is not always successful in women with more than one baby. This is because the position of the babies in the uterus can make it hard to get a tissue sample.

What happens after chorionic villus sampling?

The tissue samples are sent to a lab to be checked. Early results may be available in 48 hours. Final results are usually ready in about 7 to 10 days.

After the procedure, call your healthcare provider if:

  • You have bleeding
  • You have fluid leaking from your vagina
  • You have cramps that are getting worse
  • You have a fever of 100.4 degrees F (38 degrees C) or higher

Next steps

Before you agree to the test or the procedure make sure you know:

  • The name of the test or procedure
  • The reason you are having the test or procedure
  • What results to expect and what they mean
  • The risks and benefits of the test or procedure
  • What the possible side effects or complications are
  • When and where you are to have the test or procedure
  • Who will do the test or procedure and what that person’s qualifications are
  • What would       happen if you did not have the test or procedure
  • Any alternative tests or procedures to think about
  • When and how will you get the results
  • Who to call after the test or procedure if you have questions or problems
  • How much will you have to pay for the test or procedure
Chorionic Villus Sampling - WellSpan Health

Online Medical Reviewer: Berry, Judith, PhD, APRN
Online Medical Reviewer: Holloway, Beth, RN, M.Ed.
Last Review Date: 2015-04-27T00:00:00
Last Modified Date: 2016-07-28T00:00:00
Published Date: 2016-07-28T00:00:00
Last Review Date: 2007-03-30T00:00:00
© 2016 WellSpan Health. All Rights Reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Are you sure you would like to cancel?

All information will be lost.

Yes No ×

About the provider search

This search will provide you with WellSpan Medical Group and Northern Lancaster County (Ephrata) Medical Group primary care physicians and specialists. If we don’t have a WellSpan Medical Group physician to meet your criteria, the search will expand to include community physicians who partner with WellSpan Medical Group physicians through the WellSpan Provider Network or provide care to patients on the Medical Staffs of WellSpan’s Hospitals.


Schedule Your Next Appointment Online with MyWellSpan

Use your MyWellSpan patient portal any time to view available appointments, and pick the date and time that best suits your schedule.

Go to MyWellSpan

New to this practice?

If you don't have a WellSpan primary care provider and would like to schedule a new patient appointment with a provider who is accepting patients, just log into your MyWellSpan account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to see the offices that are accepting new patients in relation to your zip code. If you are not enrolled in MyWellSpan, go to https://my.wellspan.org, call 1-866-638-1842 or speak with a member of the staff at a participating facility to sign up. New patient scheduling not available at all practices/programs.

Already a patient at this practice?

If you already have a relationship with a WellSpan practice, simply log into your account, and go to the Appointment Center section. As you progress through the scheduling process, you will be able to schedule an appointment with any provider or practice that already counts you as a patient. Online scheduling varies by practice/program.