What does the NIPT test for?
NIPT (non-invasive prenatal testing) analyses fragments of your baby’s DNA circulating in your blood to screen for the three most common chromosomal conditions: Down’s syndrome (trisomy 21), Edwards’ syndrome (trisomy 18) and Patau’s syndrome (trisomy 13). It can also report your baby’s sex and, if requested, screen for sex chromosome conditions. It is a screening test, not a diagnosis.
How accurate is NIPT?
For Down’s syndrome NIPT detects more than 99% of affected pregnancies with a false-positive rate below 0.1%, which makes it far more accurate than the NHS combined test. For Edwards’ and Patau’s syndromes detection is slightly lower but still very high. Because it is a screening test, a high-chance result is always confirmed with a diagnostic test before any decision is made.
When can I have NIPT?
From 10 weeks of pregnancy, once there is enough of your baby’s DNA in your blood to analyse, and at any point after that. Many parents combine it with their dating scan at 11 to 13 weeks. There is no upper limit: NIPT can be done later in pregnancy if you decide you would like the information.
How is NIPT done?
A single blood sample from your arm, like any routine blood test, with no risk to your baby. Before the sample is taken your sonographer performs a pregnancy ultrasound to confirm the heartbeat, check your dates and count the number of babies, because the laboratory needs that information to interpret the result. The appointment takes around 30 minutes.
How long do NIPT results take?
Five to seven working days from the sample reaching the laboratory. As soon as your result arrives we contact you, and your sonographer talks you through what it means rather than simply sending a report. The written result is also published to your secure patient portal.
Can NIPT tell me the sex of my baby?
Yes, from 10 weeks and with very high accuracy, because it reads the baby’s own DNA rather than relying on what can be seen on a scan. Just tell us whether you would like the sex included on your report or kept off it. Many parents use NIPT for an early, reliable answer well before the 16-week gender scan.
Can NIPT be wrong about the gender?
Very rarely. Because NIPT reads the baby’s own DNA, its sex result is more than 99% accurate, far more reliable than an early scan. The rare exceptions involve twins, a vanished twin, or very low fetal DNA in the sample, which is why we confirm the number of babies on the ultrasound first. If a later scan ever disagrees with the NIPT sex result, we would look into why rather than assume either is right.
What happens if my NIPT result is high chance?
A high-chance result means the condition is likely, not certain, so the next step is a diagnostic test (CVS or amniocentesis) which examines your baby’s cells directly. We explain your result in full, answer every question and arrange a prompt referral to a fetal medicine specialist for counselling and diagnostic testing, with your report and scan images.
Can NIPT be wrong or give no result?
Rarely. False positives and false negatives are uncommon but possible, which is why a high-chance result is confirmed before anything is decided. In a small number of cases, around 1 to 3%, the sample contains too little fetal DNA to analyse, more commonly early in pregnancy or at a higher body weight. If that happens, a repeat sample is taken, usually a week or two later.
Is NIPT suitable for twins?
Yes, for most twin pregnancies NIPT can screen for Down’s, Edwards’ and Patau’s syndromes, although the result applies to the pregnancy as a whole rather than each baby individually, and sex chromosome screening is limited. Your sonographer confirms the number of babies and chorionicity at the ultrasound so the laboratory can report correctly.
How is NIPT different from the NHS combined test?
The NHS combined test at 11 to 14 weeks uses a nuchal translucency measurement and blood markers to give a chance result, and detects roughly 85% of Down’s syndrome cases. NIPT reads the baby’s DNA directly and detects over 99%, with far fewer false alarms, which means fewer parents are sent for invasive testing unnecessarily. On the NHS, NIPT is usually only offered after a higher-chance combined result.
Which NIPT test do you use, and how do Harmony, Panorama and the others compare?
All the leading NIPT tests, including Harmony, work on the same principle: analysing cell-free fetal DNA in your blood in an accredited laboratory, with very similar accuracy for Down’s, Edwards’ and Patau’s syndromes. They differ mainly in optional extras such as sex chromosome and microdeletion screening and in turnaround time. We use an established laboratory NIPT with results in five to seven working days; ask us when you book if you have a particular test or add-on in mind.
Can NIPT detect autism, cerebral palsy or other conditions?
No. NIPT screens for specific chromosomal conditions only, chiefly trisomies 21, 18 and 13, and, if requested, the sex chromosomes. It cannot detect autism, cerebral palsy, structural problems such as heart or spine defects, or most genetic disorders. Structural conditions are looked for at the anomaly scan at 18 to 24 weeks; no prenatal test screens for autism.
Do I need to fast or prepare for NIPT?
No. Eat and drink normally, take your usual medication and come straight from work if that suits. Being well hydrated makes the blood sample easier. A comfortably full bladder helps the ultrasound part if you are at the earlier end of the window.
Is NIPT safe for my baby?
Completely. It is a blood test from your arm, so unlike CVS or amniocentesis it carries no risk of miscarriage, and the accompanying ultrasound uses sound waves, not radiation. That safety is exactly why NIPT is used as the first step, with invasive testing reserved for confirming a high-chance result.
How much does a private NIPT test cost in London?
£525 at Harley Street Ultrasound, which includes the laboratory test, the pregnancy ultrasound on the day, your sonographer’s time, your results explained to you, and your written report on your portal. You can book online from 10 weeks without a referral.
Can I have NIPT and a dating scan together?
Yes, and it is the most popular way to do it. The ultrasound that forms part of the NIPT appointment confirms your dates and the number of babies, so if you are between 10 and 15 weeks it does the job of a dating scan in the same visit. Ask us about combining the two when you book.
What if something needs a closer look?
Your sonographer tells you in the room, gently and in plain English, and explains exactly what it means. You are never sent home to wait for a letter. Most of the time a finding simply needs a repeat scan in a week or two, or a measurement checked again at the next routine scan.
If something genuinely needs attention, a consultant review is available the same day, and we arrange the next step for you: a referral to a fetal medicine specialist or early pregnancy unit, with your report and images, through our hospital partners. You will not be left alone with a worry.
Do I need a referral?
No. Harley Street Ultrasound is a private clinic, so you can book a nipt test in London directly online or by phone, with no GP or midwife letter and no waiting list. Same-day and next-day appointments are usually available, and we are at 99 Harley Street, a short walk from Regent’s Park and Oxford Circus stations.
The price is published before you book: £525, all fees inclusive, covering the scan, your sonographer’s time, your scan images and your written report. Pregnancy scans are usually self-pay; if you are insured, check whether your policy covers pregnancy scanning before you book.
How soon will I have the written report?
The same day. You will already know what was seen, because your sonographer explains everything on screen as the scan happens, and your written report is published to your secure patient portal with your images before the day ends, ready to share with your midwife, GP or consultant.
Your scan images are on your secure portal the same day.
Is ultrasound safe for my baby?
Yes. Ultrasound uses sound waves, not radiation, and has been used in pregnancy for more than fifty years with no confirmed harmful effects on babies. Our sonographers keep scan times to what is clinically needed and use hospital-grade equipment, so a scan can be repeated safely whenever it is useful.
Can I still have my NHS scans afterwards?
Yes, completely. A private scan with us never affects your NHS maternity care: keep every NHS appointment as planned. Many parents book with us for extra reassurance between NHS scans, or for a scan the NHS does not routinely offer. If anything needs attention, your sonographer writes to your midwife or GP so that you re-enter the NHS pathway with the findings already in hand.
