For the last ten years doctors have been using the results of the Nuchal Translucency Scan to advise pregnant women and their partners on their risk of having a baby with Downs syndrome, or other abnormalities. The Nuchal Translucency Scan looks at the skin fold on the back of the baby’s neck at about 12 weeks. This has been further refined by looking at the nose bone of the baby with an additional blood test to identify two pregnancy hormones.
This is the combined test and has achieved a positive predictive value of about 84%. Women with a high risk have an option to proceed to chorion villous sampling (CVS) or amniocentesis. These are invasive tests that carry a miscarriage risk of about 1:100. This is changing now that the NIPT is available. Harmony is marketed by Ariosa Diagnostics and Panorama by Natera inc. They use different techniques. In other countries there are other similar tests available: MaternitT21 by Sequenom CMM, Verifi by Verinata Health and NIFTY by BGI Health.
|HARMONY TEST||PANORAMA TEST||SAFE TEST|
|TEST AVAILABLE FROM||10 weeks||9 weeks||10 weeks|
| DOWN SYNDROME
|Positive predictive value||93% (women aged 35)||91%|
|False positive rate||<0.1%||0%||<1%|
| EDWARDS SYNDROME
|Positive predictive value||Not specified||93%|
|False positive rate||<0.1%||0.1%||<1%|
| PATAU’S SYNDROME
|Positive predictive value||Not specified||38%|
|False positive rate||<0.1%||0%||<1%|
| TURNERS SYNDROME
|Positive predictive value||Not specified||50%||N/A|
|False positive rate||Not specified||<0.1%||N/A|
|TRIPLOIDY||Sensitivity||Not offered||>99%||Not offered|
|Positive predictive value||N/A||5.3%||N/A|
|FETAL GENDER (Optional)||Sensitivity||>99%||>99%||>95%|
|Sensitivity||Not offered||95.7%||Not offered|
|Positive predictive value||N/A||20%||N/A|
|ADDITIONAL MICRODELETIONS||Sensitivity||N/A||93.8%->99%||Not offered|
|Positive predictive value||N/A||2%-20% Dependent on FR|
|RESULTS AVAILABLE||3-7 days||7-14 days||3-7 days|
|FETAL FRACTION MEASURED||Yes||Yes &integrated into microdeletion sensitivity.||Yes & integrated into risk assessment|
|AVALIABLE FOR TWINS||Yes||No||Yes|
|Sensitivity||93%-99%||95% for dichorionic twins|
|AVAILABLE FOR DONOR||Yes – singleton donor||No||Yes|
|AVAILABLE FOR VANISHING TWIN||No||No||Yes|
It has been discovered that a blood sample taken from the mother at any time from approximately 10 weeks of pregnancy can be analysed for cell free fetal DNA, which is essentially a marker in the mother’s blood of the DNA of the baby. The result of the simple blood test has a detection rate of more than 99% which will hugely reduce the need for invasive testing by CVS or amniocentesis. This is great news for couples because it eliminates the risk of miscarriage of the pregnancy. It is important that an ultrasound scan is performed just before the blood test to confirm the pregnancy, and to check if the mother is carrying twins or more. NIPT can now be used in twin or more, singleton donor and surrogate pregnancies.
Anyone who is anxious about her baby having a chromosomal abnormality such as Downs, Edwards, Patau's syndrome or a sex chromosome abnormality. It is predicted that in 10 years it will become available for all on the NHS. Women who may need it are those that are older (particularly over 40 years), have already had a chromosomally abnormal pregnancy or who are at particular risk of miscarriage should they have an amniocentesis or chorionic villous sample.
The result is usually available within 3-8 working days. There is approximately a 2% chance that no result is obtained with Harmony, 2% with Panorama and less than 1% with SAFE test. This is not a positive or negative test: it is an unsuccessful test. An offer of a repeat test is made free of charge. This is usually successful. In rare circumstances the result can take longer than 14 days. We understand it can be a stressful time waiting for results and we will endeavour to communicate any delays to our patients as soon as we receive information from the laboratory.
The result is expressed as a probability. It is a screening test and not a diagnostic test. A result form of a low risk test is shown below. A low risk test result gives a risk of a chromosomal problem of less than 1:10000. A high risk result gives a risk of greater than 99%. A high risk result does not confirm that the baby has the chromosome abnormality. An amniocentesis or chorionic villous sampling is necessary to give a diagnosis. The couple are counselled about this.
The test is currently £500 including the ultrasound scan when done on a weekday. Any appointment after 5.00pm carries a £30 surcharge. If you would like to come in on a Saturday or Sunday the cost is £550.
Depending on how many weeks pregnant you are, you will still have the opportunity to have a 12 week scan privately or with the NHS. The focus of the 12 week scan will change as you will already have the result of the Downs syndrome test, so the 12 week scan will look at the baby in detail for structural abnormalities (these may exist without a chromosomal abnormality). You will still have the opportunity to have the later scans, such as the 20 weeks scan, as before. If the NIPT is low risk then it is important that the person conducting the 12 week scan is aware of this. If the test is high risk then you should return to The Birth Company or a good NHS unit for further counselling.
Yes. Structural abnormalities such as Spina Bifida, heart defects and a poorly growing baby will only be seen on scans and often not until later scans. These scans should still be undertaken.
' Professional and reassuring 'Helen Campbell
The sonographer was ready as soon as I arrived, and she was extremely calming, personable and professional. The scan and blood test where efficient without feeling rushed and all very easy. These appointments can feel uneasy and make you feel anxious but I felt reassured and in professional hands the whole time
I saw Kate throughout my first pregnancy and am now doing so again with my second. She is absolutely amazing, she explains everything really clearly, and has answered all sorts of bizarre questions and worries I have had. On top of being clinically excellent she is also just the loveliest person and always a pleasure to see.Sarah Elliott
We had the harmony test with the Birth Company and had a reassurance scan with sonographer Kirsty McGarry who was absolutely lovely and really put our minds at rest. We had been scared by our NHS dating scan and left feeling like there was something wrong. We explained the situation and was treated very professionally and with good care. Also speedy appointments also as I had phone in the morning and got an appointment by afternoon. So thankful.Ashley and Tom
Really friendly, efficient service. Great experience overall. Had the Panorama. My appointment was with Kate who was absolutely fantastic. The results came really quickly. Have a comparison with private healthcare elsewhere and must say that The Birth Company was just how I would like to be treated when I pay for medical services - attentively, calmly, friendly, in a pleasant environment that doesn't look like hospital. Top marks!Anna
' Efficient, friendly and always on hand to provide last minute appointments 'Hannah Murphy
The Birth Company has been excellent, providing timely scans and blood tests during my IVF treatment abroad. Staff are always friendly and extremely efficient. I would highly recommend coming here.
' Professional and friendly 'Lyndsey Dilla
When I first contacted the Birth Company I spoke to Danielle. She was fantastic. She went above & beyond to put me at easy & make the journey from Kent as stress free as possible. Every staff member that myself and my husband have come into contact with have been approachable, professional and friendly. Kate scanned me the first time and put me completely at easy. Lisa on reception is professional and very approachable. Highly recommended
' Highly recommended 'Emelie
Donald was so lovely! I was so nervous as I have a bad history and he was super quick and confirmed my baby's heartbeat as quickly as he could. He spent time showing me the baby and the anatomy and it was the best money I have ever spent! The reception girls were lovely too - considering they deal with babies day in day out they were super excited for me! Thank you so much one and all! If only I lived in London and could have all my scans with you!
Great Portland Street