Harmony test for prenatal screening

The Harmony test is based on the latest advances in molecular biology. The prenatal test is a sophisticated diagnostic test for prenatal screening. A blood test can accurately detect the risk of the following chromosomal conditions:

  • Down's syndrome (trisomy 21)
  • Edward syndrome
  • Patau syndrome (trisomy 13)

Harmony is more accurate than traditional Down syndrome blood tests and much less likely to give a false-positive result. That means there will be much less chance your doctor would recommend follow-up testing, such as amniocentesis.If you are particularly worried about birth disabilities or defects, the Harmony test can detect these with a high degree of accuracy.

When you are pregnant, your blood contains fragments of your baby’s DNA. Harmony Prenatal Test is a new type of test that analyzes DNA in a sample of your blood to predict the risk of Down syndrome (trisomy 21) and certain other genetic conditions.

The number of chromosomes in the baby can be worked out by measuring the cell-free fetal DNA in the mother’s blood. The test needs a sample of the mother’s blood rather than cells from the placenta, as in a chorionic villous sample (CVS), or fluid from around the baby as in an amniocentesis. Both CVS and amniocentesis require a needle to be inserted into the womb and therefore carry a risk of miscarriage but because the Harmony test only needs a blood sample from the mother, it is non-invasive and therefore does not increase risk of miscarriage.

  • The test identifies 99%, of the fetuses with trisomy 21, 97% of fetuses with trisomy 18 and 92% of fetuses with trisomy 13.
  • If the test results suggest a high risk that the fetus has trisomy 21 or 18 or 13 it does not mean that the fetus definitely has one of these defects. In this circumstance, it is recommended to proceed to having a CVS or amnio.
  • If the test shows that there is a low risk (less than 1 in 10,000) of abnormality it is unlikely that the fetus has one of the defects listed above.
  • The Harmony test does not provide information on other rare chromosomal abnormalities. If the scan at 11-13 weeks shows a high nuchal translucency or major defects, the risk for other rare chromosomal defects may be higher. In this circumstance, it is recommended to proceed to having a CVS or amnio.
  • The Harmony test does not provide information on physical defects, such as heart or brain abnormalities and spina bifida, or fetal growth. It is therefore advisable that you still have ultrasound scans at 11-13 weeks and at 20-22 weeks to examine the fetal anatomy and at 30-32 weeks to examine the fetal growth.
  • The results from the test will generally be available within two weeks, you will be notified as soon as results are received.

In order to undergo this test, a dating scan is also required to ensure the pregnancy is ten weeks or more.

Test and scan is £550.00. (Excludes the cost of your consultation which is between £150 - £200 depending on consultant).

For further information, please call Customer Services on 0131 316 2507.

Find a treatment, test or scan available at:


Find a consultant

Use one or more of the options below to search for a consultant and link through to view their Spire profile.


Let us help you

fill out this form and we will get back to you:

Please select a hospital

We can call you

Please enter your details below and we will call you back.

What is the aim of your enquiry?

Please select a hospital

If we are unable to reach you by phone, please include your email address so that we can get in touch...

© Spire Healthcare Group plc (2016)