Chorion Villus Sampling (CVS)

12-14 weeks

This test is usually performed to exclude Down Syndrome although it can be used to analyse other genetic problems, give a pre-birth paternal test or give a 100% accurate gender identification.

The procedure involves passing a fine needle through your tummy into the tissue on the outside of your pregnancy sac. Local anesthetic ensures that the procedure carries little discomfort and it only takes one or two minutes to perform.

This frond-like tissue or villi will eventually develop into your placenta.

Because the villi develops from your fertilized egg along with the fetus, analysis of this tissue will give the same results as if the fetus itself were examined.

A CVS is done under continuous ultrasound vision to keep any threat to your developing baby to an absolute minimum.

A tiny sample of your villi is taken and sent to the laboratory for analysis with results for Down Syndrome available in 2-3 days. Full analysis of other chromosomal problems can take up to 2 weeks.

Sometimes, if it is considered safer for your baby, we may choose to do the test through your vagina (similar to having a smear test). Being able to offer both methods enables us to keep the risks to a minimum.

There is a 1% risk of miscarriage associated with the test, and because the test is done early in the pregnancy the risk may be higher than when an Amniocentesis is performed in later pregnancy.

Most laboratory testing gives a straightforward answer, however, in about 1% of cases the results may prove inconclusive so there may need to be further discussion or testing.

The procedure is only performed by qualified Consultants on certain days so please be prepared to be flexible with your booking date.

Our highly experienced Fetal Medicine Specialists successfully perform hundreds of CVS procedures each year and you will have a thorough consultation and time to ask questions before the CVS

Before the procedure we shall need to know your blood group. If you are Rhesus Negative you will be given an injection of Anti-D at an additional cost.

Because of the preparation required for this procedure we usually ask for a £100 deposit to secure an appointment.

For bookings information and prices please see our Prices page.