![]() NIPT is intended for prenatal screening and is not intended to be the sole basis for diagnosis. Harmony is a non-invasive prenatal test (NIPT) based on cell-free DNA analysis. The Harmony® reagents and Ariosa cell-free DNA System (AcfS) software used as part of the Harmony Prenatal Test are CE Marked under the IVD Directive 98/79/EC. If the results show your baby is positive, there is then an option to undergo CVS or have an amniocentesis so that you absolutely know for sure.The Harmony® Prenatal Test was developed by Ariosa Diagnostics (San Jose, California, USA). "There are three possible results: positive, which means the baby is predicted to be affected by Down's negative, which means the baby is highly unlikely to have it, and inconclusive, which is rare but happens if there's not enough of the baby's DNA in the sample to give an accurate result. " Women need to be aware of the seriousness of a NIPT," she says. "You need to be prepared for you'll do if you get a positive result," she says. The Harmony test – or any other NIPT, for that matter - is not something to be taken lightly, says midwife Rebecca Tieken. Waiting for the results, which took a week, was nerve-wracking but they showed that my baby is very unlikely to be affected by Down's, something I feel very grateful for." My age, combined with the fact I see children with chromosomal disorders every day of my working life, meant I wanted the test, and the fact you can have it so early was important to me. "It increases again to one in 50 by the age of 45 – and I'm 43. "A woman who is 30 has one in 800 risk of having a baby with Down's but by the time she's 40, that risk rises to one in 100," she says. For example, the older a woman is, the higher her risk of having a baby with Down's.' Being an older mum-to-beīeing an 'older mum' was one reason Hannah Reed chose to have the Harmony test, although the fact she's a paediatrician specialising in genetics also played a part. In terms of who has a NIPT, often it's women with an increased risk of having a baby with chromosomal abnormalities. 'It's important to remember that a NIPT is not a diagnostic test like CVS or amniocentesis. "The Harmony test and other like it are almost 100% accurate, compared with an 80-90% detection rate for the combined test," says independent midwife Rebecca Tieken, from Independent Midwives UK. The DNA in the mother's blood is compared with the other DNA present (that of the baby's) and if the baby has Down's syndrome, for example, slightly elevated levels of a chromosome known as chromosome 21 will be detected. Most of the DNA present comes from the mother – only 10-20% is from the unborn baby. NIPT can be used from 10 weeks onwards, and involves a maternal blood test from which fragments of DNA are analysed. As well as being non-invasive, it has the added attraction of being more than 99% accurate in terms of detecting Down's and can also look for Edwards' and Patau's syndrome, which are traditionally checked for later in pregnancy with a scan that picks up physical abnormalities. It's not yet available on the NHS but private clinics offer it for between £350-£550, with results available from around a week to 10 days). Harmony is the 'brand' we're most familiar with the in the UK. A non-invasive prenatal test (NIPT) offers another option that may preclude an invasive diagnostic test from having to be considered." Both come with a risk of miscarriage (around 1%) as they are invasive tests and involve taking tissue from the placenta (CVS) or fluid from around the baby (amniocentesis). "If the result comes back as high risk, a diagnostic test such as chorionic villus sampling (CVS) or amniocentesis will be offered. "This screening is called the combined test because the risk factor for Down's is assessed from a combination of the amount of fluid at the back of the baby's neck (nuchal translucency) and hormonal markers in the mother's blood," says midwife Mervi Jokinen, who is a practice and standards advisor from the Royal College of Midwives. The first screening, which is used to detect Down's, takes place between weeks 10-14 and can be done at the same time as what's often known as the dating scan, at which you'll be given your estimated due date (EDD). NHS figures state that Down's affects 750 of the babies born in the UK and Wales every year, while one in 3000-6000 babies are born with Edwards' syndrome and one in 5000 babies are born with Patau's. All pregnant women in the UK can choose to be screened to assess their risk of having a baby with a chromosomal disorder, such as Down's, Edwards' or Patau's syndrome.
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