20/04/2016 08:39 BST | Updated 21/04/2017 06:12 BST

Demystifying The Harmony Test for Down Syndrome

Pregnancy is one of the most exciting times in a woman's life. There are so many wonderful things to look forward to, however there are undoubtedly some worries on your mind. Likely the biggest concern is the health of your unborn child. While some may opt to forgo prenatal screening, many women consider having an awareness of any possible foetal abnormalities to be completely essential, enabling them to better plan for the future.

It's an unfortunate fact that the traditional screening method, the Nuchal Translucency or 12 Week Scan leaves room for doubt, as it detects only 90% of Down fetuses. Because of this, some women desire more accurate tests, and opt for tests such as chorion villous sampling (CVS) or amniocentesis. Unfortunately these invasive procedures have a 1 in 100 risk of miscarriage.

Fortunately, thanks to cutting-edge research from Kings College London, a new simple blood test is now available that could save the lives of hundreds of babies every year. Developed by American firm Ariosa Diagnostics, the Harmony Test has been extensively screened and praised worldwide.

The Harmony Test screens for Down's syndrome and other more unusual chromosomal abnormalities such as Edwards syndrome and Patau syndrome. It is more accurate, and less invasive as opposed to more traditional testing methods.

Historically, doctors have screened for Down's syndrome and other chromosomal abnormalities using Nuchal Translucency Scanning at about 12 weeks. Women who receive 'high risk of abnormality' results are given the option to undergo chorionic villous sampling (CVS) or amniocentesis. Unfortunately, these tests are invasive, involving needle insertion into the womb. Sometimes, this can result in miscarriage.

Luckily, the Harmony Test is safer and much more reliable option. It scrutinises the baby's cell free DNA and has a detection rate of 99% for Down's syndrome, and slightly less for Edwards syndrome (98%) and Patau syndrome (80%). This is a significant accuracy improvement over earlier, more invasive methods.

It is important to note that the only way to be 100% sure that your baby is free from chromosomal abnormalities is to undergo amniocentesis or CVS testing, however the Harmony Test leaves you as sure as you can be without risking the possibility of a miscarriage. Unlike amniocentesis and CVS testing, the Harmony Test carries no risk to baby or mother. All that is required is a simple blood withdrawal from a vein in your arm.

Following the completion of the Harmony Test, there is a 10-day waiting period for the results, which are concluded in the US. You will then undergo a 12-week scan, which will look for any structural abnormalities. It is important to note that if the Harmony Test is negative, then it is necessary that the sonographer is aware of that. In the unfortunate event that the test is positive, it is recommended that you seek counselling. This may be available either on the NHS or through a private healthcare provider. Unfortunately, The Harmony Test is not currently available on the NHS.

I will be discussing Non-Invasive Prenatal Testing (NIPT) and The Harmony Test in a seminar at 12pm, Sat 21 May at the Private Pregnancy UK Show at the Royal Institution, London. www.privatepregnancy.co.uk