Chorionic villus samplingWhy it's offered

Chorionic villus sampling (CVS) is only offered to pregnant women with an increased risk of having a baby with a genetic or chromosomal condition. It can diagnose a range of conditions.

Chorionic villus sampling (CVS) is only offered to pregnant women with an increased risk of having a baby with a genetic or chromosomal condition. It can diagnose a range of conditions.

You'll be offered CVS if your test results or medical or family history suggest you have a higher chance of having a baby with a genetic or chromosomal condition.

You don't have to have the test if it's offered – it's up to you to decide whether you want it.

What conditions can CVS detect?

CVS can be used to diagnose a number of conditions, including:

CVS can't detect neural tube defects. These are birth defects affecting the brain and the spinal cord, such as spina bifida, which can usually be detected with an ultrasound scan.

Deciding whether to have CVS

If you're offered CVS, ask your doctor or midwife what the procedure involves and what the risks and benefits are before deciding whether to have it.

You may also find it helpful to contact a support group, such as Antenatal Results and Choices (ARC). ARC is a charity that provides information, advice and support on all issues related to screening during pregnancy.

Reasons to have CVS

CVS will usually tell you whether your baby will be born with any of the conditions that were tested for.

If no problem is found, it may be reassuring. If a condition is detected, you'll have plenty of time to decide how you want to proceed with your pregnancy.

Read more about the results of CVS for more information.

Reasons not to have CVS

There's a 0.5 to 1% chance you could have a miscarriage after the procedure. You may feel this risk outweighs the potential benefits of the test. Read more about the risks of CVS.

Some women decide they don't want to know if there's a problem with their baby until later on. You may choose to have an alternative test called amniocentesis later in your pregnancy instead, or you might just want to find out when your baby is born.

Page last reviewed: 19/07/2018
Next review due: 19/07/2021