What is Amniocentesis (Amnio)?

Amniocentesis is the removal of a small amount of amniotic fluid from the sac around the baby.

This fluid contains cells which come from the baby and the placenta. This test is usually performed at 16 weeks into the pregnancy.

Amnio Procedure

After cleaning the skin with antiseptic, a fine needle is inserted under ultrasound guidance through the mother's abdomen into a pool of amniotic fluid. A small amount of fluid is withdrawn and the needle removed. The amniotic fluid is sent to the laboratory for testing. A chromosome result will take two to three weeks. A biochemical or direct genetic (DNA) test may take longer.

The chromosome test establishes the sex of the baby and if you wish to know this information you must ask the person who gives you the result.

Amniocentesis carries a small risk of causing a miscarriage. The average risk is one chance in 200.

Are the Procedures Painful?

Most women say amniocentesis is not painful. Some women, however, feel discomfort. Some women experience discomfort during and after CVS.

For both tests it is advisable to rest for the remainder of the day. You may like to have your partner, a family member or friend with you on the day of the test.

Another popular idea is to bring along a hand-held CD player or mp3 player with earphones to help you relax.

What Will Happen After the Test?

There is a risk of naturally occurring miscarriage in all pregnancies. The risk is highest in early pregnancy and increases with the age of the mother. The risks quoted for prenatal tests are in addition to this naturally occurring risk of miscarriage.

Most people have normal results after the test. If the test shows the baby to have a problem, however, you will have the opportunity to discuss the results with your doctor, genetic counsellor or geneticist.

It is important to realise that while the combination of ultrasound scan and CVS or amniocentesis goes a long way towards identifying your baby as normal, it does not guarantee that every possible abnormality has been excluded.

What is the Philosophy of Mater Mothers' Hospital?

Antenatal testing is routinely undertaken in all major obstetric-maternity hospitals. We, too, offer this service to women who may have concerns that the unborn baby is at risk of suffering from some major abnormality. We offer the test in the hope that these concerns can be alleviated, or that something can be done to help the baby while still in the uterus, at the time of delivery or immediately after the birth.

In keeping with Catholic Church teaching and the philosophy of the hospital, termination of pregnancy is not provided at Mater Mothers' Hospital. We do offer a full range of pastoral care, ethical advice and counselling support to supplement medical and nursing services to all women and their families. Please ask one of the staff to help you arrange an appointment if you would like to access these services.