Chorionic villus sampling test (CVS)



A test taken during pregnancy to check if your baby has a DNA condition such as Down's, Edwards' or Patau's syndromes

Enquiries & Appointments

Pregnant lady, early pregnancy

Our Chorionic villus sampling test (CVS) locations

The Portland Hospital

The Portland Hospital

205-209 Great Portland Street W1W 5AH London

This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.

About a DNA test during pregnancy

A chorionic villus sampling diagnostic test (CVS) is performed between 11 to 14 weeks of pregnancy.

It is not a routine test and is usually only carried out if there is a higher risk that your baby could have a condition related to their DNA structure (genetic or chromosomal abnormalities).

Need to know

The test involves removing and testing a small sample of cells from your placenta (the organ linking your blood supply to your unborn baby's). Your consultant will do this using ultrasound guidance.

A sample of placental tissue is taken using a needle inserted through your abdominal wall or with a pair of fine forceps (like tongs) through your cervix. The tissue collected is then tested for DNA (genetic or chromosomal) abnormalities. Your preliminary results are usually available within two to three working days with a full report available within two to three weeks.

Your consultant will let you know how best to prepare for this test.

You will be able to leave and carry on with your day immediately following the test. The initial results should be available within three working days and this will tell you whether a major chromosome condition such as Down's, Edwards' or Patau's syndrome, has been discovered.

Rarer conditions may take two to three weeks to be diagnosed. If the test shows that your baby has a genetic or chromosome condition, your consultant will discuss the results with you. They will also let you know all of the options open to you.