Amniocentesis is only offered to pregnant women who have a higher chance of having a baby with a genetic or chromosomal condition. It can diagnose a range of conditions.

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 may be offered amniocentesis.

You do not have to take the test. It's up to you to decide whether you want it.

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

• Down's syndrome – all children born with Down's syndrome have some degree of learning disability and delayed development, but this varies widely between individual children
• Edwards' syndrome and Patau's syndrome – conditions that can result in miscarriage, stillbirth or severe physical problems and learning disabilities
• cystic fibrosis – a condition where the lungs and digestive system become clogged with thick, sticky mucus
• muscular dystrophy – a condition causing progressive muscle weakness and disability
• sickle cell disease – where the red blood cells develop abnormally and are unable to carry oxygen around the body properly
• thalassaemia – a condition that affects red blood cells and can cause anaemia, restricted growth and organ damage

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

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

Reasons to have amniocentesis

The test will usually be able to tell you for certain if your baby will or will not be born with any of the conditions tested for.

You might find that your baby does not have the condition screening tests said they might have, which can be reassuring.

But if the test confirms that your baby does have the condition they were tested for, you can decide how you'd like to proceed.

Find out more about the results of amniocentesis

Reasons not to have amniocentesis

There's a risk of miscarrying the baby. Up to 1 out of every 100 women who have amniocentesis will miscarry. You may feel this outweighs the potential benefits of the test.

Some women decide they'd rather find out if their baby has a genetic condition when their baby's born.

Find out more about the risks of amniocentesis