The Harmony Prenatal Test - The only place in South West England to offer this service
The very latest, most accurate non-invasive method that screens for Down’s Syndrome. The HarmonyTM test is based on the latest advances in molecular biology. Scientists have discovered that there is a small amount of the baby’s DNA (cell-free fetal DNA) in the mother’s blood. This DNA is thought to come from the placenta. 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 then 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. Because the Harmony test only needs a blood sample from the mother, it is said to be non-invasive.
How accurate is the HarmonyTM test?
The HarmonyTM test identifies more than 99% of babies with Down syndrome, 98% of babies with Edwards syndrome, and 80% of babies with Patau syndrome. For comparison, the combined test, using a blood test and measurement of the baby’s nuchal translucency by ultrasound, identifies up to 95% of babies with these syndromes.
Who can have the HarmonyTM test?
The Harmony test can be ordered by healthcare professionals for women with pregnancies of at least 10 weeks’ gestational age. The Harmony test is available for any singleton or twin pregnancy, including all those conceived by IVF. This test does not assess risk for mosaicism, partial trisomies or translocations.
What happens at my visit?
You will be seen by a consultant obstetrician or midwife specialist in ultrasound. We will go through the test and answer any questions you may have.
If you are between 10 and 11 weeks:
You will need two visits to the Spire Bristol Hospital.
The first visit will be between 10 weeks to 10 weeks and 6 days of your pregnancy. You will have an ultrasound scan and will will also take a sample of blood from you that will be used for the HarmonyTM test.
The second visit will be two weeks later, at 12 to 13 weeks. At this visit we will discuss the results of the HarmonyTM test and will also carry out an early abnormality scan. This scan includes examination of the baby’s major organs, including the brain, heart, abdomen, stomach, bladder, limbs and the nuchal translucency (NT) measurement. The NT measurement is another test, and can be abnormal in babies who have heart problems, or some of the rarer genetic problems, which are not detected by the HarmonyTM test.
If we see any abnormalities, or the NT is over 3.5 mm, we will discuss the implications with you in detail. In the majority of cases, the baby’s organs are normal and the NT is less then 3.5 mm.
It is sometimes necessary to perform an internal (trans-vaginal) scan, depending on the position of your womb and the baby’s position, to get the best views. This involves placing an ultrasound probe in the vagina. It is completely safe and most women find this scan less uncomfortable then a smear test.
If you are between 11 and 14 + 1 weeks:
You will need one visit to the Spire Bristol Hospital.
You will have an early abnormality scan to check the baby’s organs and measure the NT. We will also take a sample of blood from you that will be used for the HarmonyTM test.
If any abnormalities are seen, or the NT is over 3.5 mm, we will discuss the implications with you in detail. In the majority of cases, the baby’s organs are normal and the NT is less then 3.5 mm.
If you are more than 14+1 weeks:
You will need one visit to the Spire Bristol Hospital.
You may have already had Down syndrome screening and an anomaly scan at 18-20 weeks. The HarmonyTM test is still available to you. We would be happy to see you at the Spire Bristol Hospital to review the results of any previous scans and tests. We will perform a detailed scan to examine the baby’s organs and growth. We will also take a sample of blood from you that will be used for the HarmonyTM test.
Who performs the blood test?
We will send your blood sample, with your personal information (including name, date of birth, gestational age), to The Doctors Laboratory based in Harley Street, London.
When can I expect to get my results?
The results of the HarmonyTM test will generally be available within two weeks.
Do you always get a result?
There needs to be enough cell-free fetal DNA in your blood to be able to provide a result. In 3 to 5% of cases, there is not enough cell-free fetal DNA and another blood sample is required. If this happens, the additional sample will be processed at no extra charge.
What will the HarmonyTM test result say?
The result from the HarmonyTM test is expressed as high or low risk. A high risk result indicates that the baby has a high risk of Down, Edwards or Patau syndrome and this is found in 1% of women. To find out if the baby definitely has one of the syndromes a CVS or amniocentesis needs to be performed. For comparison, combined screening using a blood test and measurement of the baby’s nuchal translucency by ultrasound (the standard NHS test), gives a high risk result in 5% of women, who need to have a CVS or amniocentesis, which carries a risk of miscarriage. Overall, the HarmonyTM test will detect more babies with Down, Edwards and Patau syndromes, and fewer women would need a CVS or amniocentesis then with combined screening.
If the test results show a low risk, it is very unlikely that the baby has one of the syndromes, but not all affected babies will be detected.
How will I get my result?
We will either give them to you at the time of your second visit to the Spire Bristol Hospital at 12 to 13 weeks, or contact you by letter if you are not going to have a second visit.
Do I need to have any other tests?
The HarmonyTM test does not provide information about other rare chromosomal abnormalities. If the ultrasound scan shows a high nuchal translucency or other physical defects the risk for some rare chromosomal defects may be high. In such cases, we will discuss the implications and your choices in detail. The HarmonyTM test does not provide information on physical defects such as spina bifida, or information on fetal growth. It is therefore advisable that you have all the usual ultrasound scans during your pregnancy.
To find out more about The Harmony Blood Test at Spire Bristol Hospital please contact our Bookings Team on 0117 980 4080
Spire Bristol Hospital offers a broad range of blood and tissue tests to aid in the diagnosis of everything from allergies and deficiencies to fertility levels and blood disorders.
Our nurses and phlebotomists at Spire Bristol Hospital are available to perform a wide range of tests that you may require. From routine blood tests to highly complex analysis, we can help you to gain a diagnosis as quickly as possible.
For further information please call 0117 980 4080 or complete the form on the right-hand side of this page.