What is Transcervical Chorionic Villus Sampling (CVS)

Transcervical chorionic villus sampling is a procedure that is done to find out information about the genes of a baby in the womb (fetus). Genes contain the instructions for how a body develops and the family traits that are passed down (inherited) from parent to child.

CVS can test whether there are genetic problems (abnormalities) that could lead to certain health conditions.

In this procedure, a sample of placental tissue from the small, finger-like growths in the placenta (chorionic villi) is removed for testing.

This sampling is done by inserting a thin tube (catheter) through the vagina to the upper opening (cervix). The cells in this tissue sample contain genetic information about your unborn baby.

Tell a health care provider about:

• Any current or previous pregnancy complications.
• Any allergies you have.
• All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
• Any problems you or family members have had with anesthetic medicines.
• Any blood disorders you have.
• Any surgeries you have had.
• Any medical conditions you have, including any STDs (sexually transmitted diseases), such as genital herpes or gonorrhea.
• Any vaginal bleeding you have had during your pregnancy.

What are the risks?

Generally, this is a safe procedure. However, problems may occur, including:

• Infection.
• Pregnancy complications, including miscarriage. This is rare.
• Rh disease. This blood condition can happen if your blood mixes with your baby’s blood and then parts of your blood react badly to proteins in your baby’s blood.

What happens before the procedure?

• Follow instructions from your health care provider about eating or drinking restrictions.
• Ask your health care provider about:
  • Changing or stopping your regular medicines. This is especially important if you are taking diabetes medicines or blood thinners.
  • Taking medicines that can thin your blood. Do not take these medicines before your procedure if your health care provider instructs you not to.

What happens during the procedure?

• To reduce your risk of infection:
  • Your health care team will wash or sanitize their hands.
  • Your skin will be washed with soap.
• Your health care provider will do an imaging study using sound waves (ultrasound) to locate the placenta and to guide the procedure.
• Your health care provider will place a tool (speculum) into your vagina to hold it open.
• The catheter will be threaded through your cervix and into the placenta.
• A small sample of chorionic villus cells will be removed using suction.
• Your baby’s heart rate will be checked.

The procedure may vary among health care providers and hospitals.

What happens after the procedure?

• You may be given a type of blood product (immune globulin) to prevent Rh disease.
• It is your responsibility to get the results of your procedure. Ask your health care provider or the department performing the procedure when your results will be ready.

Transcervical Chorionic Villus Sampling, Care After

Refer to this sheet in the next few weeks. These instructions provide you with information about caring for yourself after your procedure. Your health care provider may also give you more specific instructions. Your treatment has been planned according to current medical practices, but problems sometimes occur. Call your health care provider if you have any problems or questions after your procedure.

What can I expect after the procedure?

After the procedure, it is common to have:

• Mild cramps.
• Mild vaginal bleeding or spotting.
• Soreness.

Follow these instructions at home:

• Rest as told by your health care provider. Ask your health care provider what activities are safe for you to do.
• Drink enough fluid to keep your urine clear or pale yellow. This helps to prevent cramping.
• Until your health care provider approves:
  • Do not have sex.
  • Do not put a tampon or anything else into your vagina.
  • Do not douche.
  • Do not travel.
• If CVS shows that your baby has a birth defect, talk with your health care provider about all of your options. Some babies may get treatment before birth or soon after birth.

Contact a health care provider if:

• You have more pain or cramping in the lower abdomen.
• You have a fever or chills.
• You have an increase in vaginal discharge.

Get help right away if:

• You are leaking clear or blood-tinged fluid from your vagina.
• You develop pus or bad-smelling vaginal discharge.
• You have severe pain or cramping.
• You have heavy bleeding from your vagina.