Results of amniocentesis

After amniocentesis has been carried out, the sample of amniotic fluid will besent to a laboratory for testing.

Getting the results

The first results should be available within three working days, and this will tell you whether a major chromosome problem such as Trisomy 21 has been found.

If rarer conditions are also being tested for, it can take two to three weeks or more for the results to come back.

You can usually choose whether to get the results over the phone or during a face-to-face meeting at the hospital or at home. You'll also receive written confirmation of the results.

How reliable are the results?

Amniocentesis is estimated to give a definitive result in around 98-99% of cases.

However, it can't test for every birth defect and in a small number of cases it's not possible to get a conclusive result.

What the results mean

For many women who have amniocentesis, the results of the procedure will be "normal". This means that none of the genetic disorders that were tested for were found in the baby.

However, a normal result doesn't guarantee that your baby will be completely healthy, as the test only checks for conditions caused by faulty genes, and it can't exclude every possible genetic disorder.

If your test is "positive", your baby has one of the disorders it was tested for. In this instance, the implications will be fully discussed with you and you'll need to decide how to proceed.

What happens if a problem is found

If the test finds that your baby will be born with a genetic disorder, you'll speak to a number of specialists about what this means.

This may be your midwife, a doctor with experience in childhood genetic conditions, a geneticist and/or a genetic counsellor.

They'll be able to give you detailed information about the condition including the problems your child may have, the treatment and support they might need, and whether their life expectancy will be affected to help you decide what to do.

There's no cure for most genetic conditions, so you'll need to consider your options carefully. Your main options are:

• continue with your pregnancy while gathering information about the condition, so you're prepared for caring for your baby
• have a termination ( abortion ) read more about termination for foetal abnormalities

This can be a very difficult decision, but you don't have to make it on your own.

As well as discussing it with specialist healthcare professionals, talk things over with your partner and speak to close friends and family, if you think it might help. The charity Antenatal Results and Choices (ARC) can also offer support and impartial information.