London Ultrasound Centre logo

From £650
incl scan

Harmony prenatal test

From 10 weeks gestation

At a glance

Available now!
A safe, non-invasive test that measures fetal cells present in the mother's blood to produce a 99% accurate Down Syndrome screening result and fetal sex (if requested).

Available from 10 weeks gestation, simply attend our centre for an accurate dating scan, provide a small blood sample and receive your result in under 7 working days.

The Harmony Prenatal Test  is an advanced yet simple screening test to detect for Down Syndrome in an unborn baby.

  • 99% accurate detection rate for 3 most common anomalies and fetal sex (if requested)
  • Completely safe and non-invasive
  • No GP referral required
  • Supersedes the nuchal, quadruple or integrated test
  • Useful to obtain a more accurate second opinion after a non-reassuring or a missed 12 week screening
  • Service performed by a highly qualified sonographer or consultant
  • Appointments available at short notice
  • Convenient central London location

You will receive

  • Results in around 7 working days
  • Two-page clinical report on your baby, plus screening results from laboratory including fetal sex (if requested)
  • Complimentary black and white picture (normally £2.50)

What happens with your results?
We will call you no more than 15 days after your appointment to let you know your results and will send a report detailing your estimated risk and fetal sex (if requested).

What the Harmony prenatal test?

The Harmony prenatal test is simply a non-invasive blood test that provides advanced screening for Down Syndrome.
It can be performed from as early as 10 weeks and exceeds the screening accuracy of the 12 week nuchal scan but does not replace the actual ultrasound scan component of that service which should still be performed at around 12 weeks gestation.

Becasue the test is non invasive it cannot harm you nor your baby.

If you have already had either the nuchal scan or integrated test and have received a high risk result you may consider this test to obtain a more accurate second opinion.

However the Harmony prenatal test is not 100% accurate nor diagnostic so we always recommend that you consider a diagnostic DNA test like a CVS or amniocentesis rather than having another screening test.

How does the Harmony prenatal test work?

Non-invasive prenatal testing  analyses microscopic traces of DNA from the unborn baby that circulate in a pregnant mother’s blood.

The test screens for the three most common birth defects caused by chromosomal abnormality:

  1. Down Syndrome
  2. Edward's Syndrome
  3. Patau Syndrome

A scan is performed to accurately date your pregnancy. For this test we cannot use any dating information from any previous scans that you may have had with this pregnancy - unless you have been scanned at our centre.
We ask you detailed questions about yourself and your pregnancy to assist with the screening test and request your signature on two consent forms.

The sample will be processed in the TDL Genetics laboratory and the resuls will be available within 5 working days. 

What detail is in the reports?

Our scan report will:

  • Check the viability of your pregnancy
  • Establish the gestational age via a series of measurements
  • Confirm the number of babies

The laboratory report will show a result, risk score and recommendation for the three common chromosomal abnormalities:

A high risk indication will be given where the result of your non-invasive prenatal test has fallen below the 1/100  threshold. If your result is 1/100 or higher risk you will be offered an invasive diagnostic test, such as a CVS or amniocentesis to give you a definite answer.

Fetal sexing in now available for both Singleton and twin pregnancies:

  • A Male result  may apply to one or both fetuses
  • A Female result applies to both fetuses
  • X and Y aneuploidy testing is not available for twin pregnancy

How accurate is the Harmony prenatal test?

Verified clinical data from the genetics laboratory:

Detection and false positive rates are calculated on a risk cut-off of 1/100.

Fetal sex reporting (detection of the Y chromosome) has an accuracy of greater than 99%.

Does the Harmony prenatal test replace my 12 week nuchal scan or a CVS/amniocentesis?

No. If you have the test before 12 weeks gestation you will still need to have a scan at 12 weeks to check on your baby's anatomy.

Nor does it replace diagnostic genetic testing. A non-reassuring screening result can only be absolutely verified by having an invasive diagnostic test such as a CVS or amniocentesis.

Is the Harmony prenatal test suitable for multiple or IVF pregnancies?

The Harmony prenatal test is suitable for naturally conceived twins. It can also be used on single IVF pregnancies including those using donor eggs.

Is the Harmony prenatal test always successful?

97+% of the time yes.

However please note that the result from every sample is subjected to a large volume of quality control checks. 3% or less will not pass this stage and in this case no result will be issued.

In this event the laboratory will repeat the analysis free of charge but there will be a delay in the result being issued.

In the unlikely event of a second failure we offer a repeat blood test at no additional charge.

Where can I learn more about the Harmony prenatal test?

For more information you may watch this video, download this brochure from the test provider or this information leaflet from our genetics laboratory.

I've heard about other non-invasive prenatal tests. Which is right for me?

The Harmony Prenatal Test is similar to the Nifty Test, the Verifi Prenatal Test by Verinata Health, the MaterniT21 Plus test by Sequenom and the Panorama Non-Invasive Test by Natera and one or two others.

We believe the Harmony Prenatal Test is the most accurate and reliable test currently available on the market.

What's my next scan?
12 week nuchal scan