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Harmony™ Test

The HarmonyTM Prenatal Test is a DNA blood test carried out in pregnancy: it allows a baby's DNA to be tested from a sample of the mother's blood. We use this non-invasive prenatal test to:

  • Check for Trisomy 21 (linked with Down syndrome)
  • Check for Trisomy 18 (Edwards syndrome)
  • Check for Trisomy 13 (Patau syndrome)
  • Determine a baby's gender (inspecting the X and Y chromosomes)


The HarmonyTM Prenatal Test is extremely accurate (99+% accuracy of diagnosis) and offers an effective replacement to amniocentesis for most women undergoing prenatal screening for chromosomal abnormalities. The test can be done early in pregnancy (from 10 weeks) and carries not risk to the mother or baby.

The HarmonyTM Prenatal Test is available in London at The Medical Chambers Kensington under the supervision of Dr David Nyberg, who was one of the first doctors to begin using the test in the US. The HarmonyTM Prenatal Test was first available in Ameica in October 2011. To date HarmonyTM Prenatal Test is not offered by the NHS. You may hear this test referred to by your antenatal care team as a non-invasive prenatal test (NIPT) or non-invasive prenatal diagnosis (NIPD). 


Comprehensive antenatal screening

The Harmony TM prenatal blood test does not replace the 12-week Nuchal scan. The scan provides crucial information about your baby's anatomical development that cannot be ascertained from a prenatal blood test, so it is important to combine ultrasound scanning with blood tests. You can have your blood sample for the DNA blood test taken at the same time as the Nuchal scan, or you can come in for it separately.


Who is the Harmony TM test for?

The HarmonyTM Prenatal Test is usually chosen when the risk of chromosome abnormality is considered high, either because of maternal age or history, or indications shown on the Nuchal (12-week) scan. Some women request it when no increase of risk is indicated as a form of reassurance.

A side benefit of the HarmonyTM Prenatal Test is that it can determine your baby's gender. Ultrasound at The Medical Chambers Kensington is also highly accurate for determining gender after 12 weeks.


What to expect when you have a HarmonyTM Test

You'll meet our nurse who will take a sample of your blood from a vein in your arm.

A specialist laboratory in the US will analyse your blood sample - there are no UK labs currently able to carry out this test. We'll have your results within 14 days.

We'll call you with the results as soon as we have them and we will send you a copy of your report. Our specialist prenatal doctor will also review the results before sending a report to your doctor.


How does the Harmony Prenatal Test TM work?

A mother's blood contains tiny amounts of DNA from her fetus, which circulates as 'cell-free' DNA (cfDNA) resulting from the natural breakdown of fetal cells (presumed to be mostly placental). In early pregnancy this cfDNA can be collected from a sample of the mother's blood and analysed to reveal the chromosomal make up of fetal DNA. So, without any invasion of the pregnancy, it offers an accurate screening test for the risk of a baby having a chromosome condition called a trisomy. A trisomy occurs when there are three copies of a particular chromosome instead of the usual two. The most common is Trisomy 21 (Down Syndrome). The other two that are checked for with the Harmony test are Trisomy 13 and 18. For more on these conditions, please follow this link to congential abnormalities and birth defects.