Amniocentesis

Each year in the UK, approximately 5% of pregnant women are offered a diagnostic test, such as amniocentesis and chorionic villus sampling (CVS). Amniocentesis is the most commonly offered diagnostic test.

What is amniocentesis?

Amniocentesis is a medical test that is carried out during pregnancy in order to assess whether the unborn baby (foetus) could develop or has developed an abnormality or serious condition.

The results of amniocentesis will indicate the likelihood of the baby developing certain chromosomal conditions, such as Down's syndrome, Edward's syndrome, and Patau's syndrome, which are all conditions where the baby is born with an extra chromosome.

Because diagnostic tests such as amniocentesis are quite invasive (involve going into the body) and carry a small risk of miscarriage, they are usually only offered to women when there is a significant risk that their baby will develop a serious condition or abnormality.

Age and history

The mother's age, medical history and family history are factors that could increase the risk of an abnormality developing in their unborn child, and they will be taken into consideration when deciding whether a diagnostic test should be offered.

If amniocentesis is recommended for you, the health professional in charge of your care will tell you why they think the procedure is necessary, and they will outline the benefits and risks involved. However, it is your decision whether or not to go ahead with the procedure. You do not have to have a diagnostic test if you do not want to.