Tummy2mummy are now performing A new Non-invasive Downs Screening Test with a 99% accuracy rate ! Cost - £450
The Harmony™ Prenatal Test
The new test, the HarmonyTM Prenatal Test, significantly improves the screening results, identifying over 99% of the affected babies as high-risk, but reporting less than 1% of normal babies as high-risk.
How does the Harmony™ Prenatal Test work?
As the baby develops, a small amount of the baby’s genetic information (cell-free DNA) passes into the mother’s blood. New genetic sequencing techniques mean that this DNA can now be analysed to identify if there is too much chromosome 21 – the extra chromosome found in Down’s syndrome.
It won’t give a definite yes / no answer, but the research to date has been promising, showing that over 99% of affected babies will be identified as high-risk, but very few normal babies will be given a high-risk result.
However it must be stressed that the test is not diagnostic and that a low-risk result does not mean that there is absolutely no risk and a high-risk result will still need an invasive test to provide certainty.
What else does the Harmony™ Prenatal Test pick up?
The Harmony™ Prenatal Test has been developed specifically as a screening test for Down’s syndrome. However the same genetic sequencing techniques can be used to look at two additional chromosomes – chromosome 18 and chromosome 13.
Just as babies with Down’s syndrome have an extra chromosome 21, babies with Edwards’ syndrome have an extra chromosome 18 and babies with Patau’s syndrome have an extra chromosome 13. However the abnormalities that babies with Edwards’ syndrome and Patau’s syndrome have are so severe that sadly these babies miscarry, are stillborn, or die shortly after birth.
The Harmony™ Prenatal Test will look at the risk of Edwards’ and Patau’s syndrome too, although the results so far suggest that the pick up rates aren’t quite so good as the Down’s syndrome detection rates (98% for Edwards’ syndrome and 80% for Patau’s syndrome), but these babies usually have abnormalities that can be seen on ultrasound scan, so certain ultrasound features should always heighten suspicion, regardless of a normal Harmony™ Prenatal Test.
How is the Harmony™ Prenatal Test done?
The Harmony™ Prenatal Test involves taking two tubes of the mother’s blood from a vein in her arm, in exactly the same way that a normal blood test is done. Other than a small amount of discomfort and possible bruising, there are no risks to the mother and absolutely no risk of harm to the baby. The sample is then sent to a laboratory in the USA, Ariosa Diagnostics Inc, who will extract cell-free DNA from the blood and carry out the Harmony™ Prenatal Test.
The results are sent back to Tummy2mummy within two weeks.