How It Is Done continued...
An ultrasound will be used to
help your doctor guide the catheter through your cervix to the placenta. An
ultrasound device (transducer) that gives off and picks up sound waves will be
passed over your belly. The reflected sound waves are sent to a computer to
make a picture of the uterus, your baby, and the placenta on a TV screen. Your
baby's heart rate can also be checked during the procedure using ultrasound.
For more information, see the topic
When the catheter is
correctly placed, a sample of chorionic villus cells will be collected.
After the sample is collected, your doctor may listen to your baby's
heart rate and check your blood pressure, pulse, and breathing.
How It Feels
If you have the procedure through the
belly, you will feel a short, sharp sting from the needle used to give the
numbing medicine. There is usually no pain when the collecting needle is put in
the belly. You may feel some cramping when the needle is inside your
Most women do not find the transcervical procedure
painful. You will probably find that this test feels similar to having a Pap
test or pelvic examination. You may feel some cramping when the catheter is
guided through your cervix.
Chorionic villus sampling (CVS) can cause
cramping, leakage of amniotic fluid, and vaginal spotting, which goes away in 1
to 2 days. You may feel some soreness where the needle was put in if you had
the belly procedure done.
CVS also increases the chance of:
- Developing a uterine infection.
- Having a miscarriage. The chance of miscarriage is higher for
transcervical CVS than for abdominal CVS.1 Overall,
one study showed the risk of miscarriage from CVS is about 1 in 400 when done
by a highly trained provider.2
- Having a
baby with arm or leg abnormalities though the chance of this happening is very
low, especially when the test is done after 10 weeks.
Chorionic villus sampling has a very small chance of
causing bleeding that could result in mixing your blood and your baby's. If you
Rh-negative blood, you will be given the Rh immune
globulin vaccine (such as RhoGAM) to prevent Rh sensitization which could harm
your baby if he or she has Rh-positive blood.
After the procedure
It is normal to have mild
cramping, leakage of a small amount amniotic fluid, and vaginal spotting for
the first day or two after the procedure. Call your doctor immediately if you
- Moderate or severe belly pain or
- More leakage of amniotic fluid from your
- More vaginal bleeding than spotting, or bright red
- Chills or a
- Redness or swelling at the needle
site if you had a belly procedure.