Chorionic Villus Sampling
CVS is requested much less often than amniocentesis. At BC Women’s, CVS is provided only on Wednesday mornings.
When your doctor or midwife requests this test, we will put your name on a waiting list. We will contact you about a week before the test. If there is no available CVS appointment, you will be offered an appointment for amniocentesis.
You should have a light meal before coming to the hospital. No other special preparation is necessary.
A doctor who has completed special training in this procedure will do your CVS. A nurse and a sonographer (ultrasound technician) will be assisting.
We advise you to not drive yourself or take public transportation (bus) after the test. For this reason, we recommend that your partner, or another person of your choosing, accompany you for your test. You may choose to have that person in the procedure room with you, or, he or she may wait in the lobby, or sit just outside the procedure room. If you have no one to come with you, we recommend that you take a taxi home.
NB. Another adult must accompany children. They may view the baby on ultrasound prior to the procedure, and then wait outside during the test.
Before having your test, a nurse will review the procedure with you and make sure that you are aware of the available options. We will answer any of your questions. She will then obtain your written consent. You will receive information to take home about what to expect after your test.
Ultrasound is used to locate the baby and placenta and to guide during the procedure. The fetus’ heart rate is recorded before (and after) the procedure and some measurements are taken to confirm the number of weeks of pregnancy.
The location of the placenta will determine whether it is possible to do the CVS and the best route for obtaining the sample.
Prior to the test, the area will be cleaned with an antibacterial solution.
- Vaginal route: the doctor will insert a speculum (like when you have a PAP test done), and using a small instrument, take a small sample from the placenta.
- Abdominal: the doctor will insert a fine needle through the abdomen into the placenta, and take a small sample. You may experience some cramping and a slight sensation of pressure.
If it is not possible to do the CVS, we will schedule you for an amniocentesis at the earliest possible appointment, after you have reached 15 weeks of pregnancy.
You do not need to stay in the hospital following your test.
We recommend that you rest for the next 24 hours. You do not have to go to bed. Resting on the couch or in a reclining chair is fine. Avoid heavy lifting and use the time to relax with a favourite book, video, etc. If you need a note to be off work, the doctor who does your procedure will sign this for you.
If you have come from outside the Vancouver area, you may want to consider staying somewhere overnight. If this is not an option for you, “take it easy” (e.g., use the elevator on the ferry or the cart to get to your departure gate at the airport, stretch and take bathroom breaks if you are driving a longer distance).
You will receive written information about what to watch for and how to contact us if you have any concerns. Mild cramping is the most common side effect, and should go away over the next 24 hours.
Read here for more information about Chorionic Villus Sampling.