What does the Amniocentesis test involve?

The test involves taking a small sample of the amniotic fluid from the patient; amniotic fluid surrounds the foetus in the womb. The amniotic fluid contains cells from the foetus, which can then be tested in a laboratory.

Before you have the test, a nurse will explain what happens during the test, outline any possible risks and explain the benefits of the test; some women choose not to have the test. If you decide to go ahead with the test, you will be asked to sign a consent form to confirm that you want to have the test and you understand that there are risks involved.

Before you have the test you will have an ultrasound scan; this enables the nurse to assess the position of the foetus and find a suitable place to take the sample of amniotic fluid. You may be offered an anaesthetic injection before the needle is placed in your abdomen but it is up to you whether or not you have the injection.

During the procedure, a long, fine needle is inserted into your abdomen; before the needle goes in your abdomen will be cleaned with an antiseptic agent, which will reduce the risk of infection. The needle will then be guided by the ultrasound and passed through the wall of the abdomen and into the amniotic sac; a sample of the amniotic fluid is then collected using a syringe. In the vast majority of cases, enough fluid is collected the first time round; however, in around 8 percent of cases, not enough fluid is collected and the needle has to be re-inserted.

Is the test painful?

Although it sounds like a daunting and painful experience, the amniocentesis test is not usually painful. Many women say they experience pains similar to period pain and the pain soon subsides once the needle has been removed.

How long does the test take?

The test should take around ten minutes; however, it may take slightly longer if the foetus is in an awkward position or is moving around.

After the test

Patients are advised to rest for a period of 24 hours after having the test; it is normal to experience pains which feel like menstrual pain and spotting (very light bleeding) during this time. If you experience any of the following symptoms you should seek urgent medical attention:

• Bleeding from the vagina
• Vaginal discharge
• A high temperature (over 38 degrees)
• Shivering or experiencing changes in temperature
• Abdominal pain
• Pain in the lower back
• Contractions