Non-invasive prenatal test (NIPT)
Screening for the common chromosome conditions from 10 weeks of pregnancy, from a simple blood test, with an Australian doctor to explain the result.
NIPT is a blood test from 10 weeks of pregnancy that screens for the most common chromosome conditions by reading fragments of placental DNA circulating in your blood. Through KnowLuna it is priced at launch, once our laboratory agreement is signed; waitlist members see the price first. Either pathway applies: bring your own doctor's signed request, or have a KnowLuna doctor request it and explain the result in a 20-minute video consult. KnowLuna requests the test; an accredited specialist genomics laboratory performs it, named on this page before ordering opens.
What it measures
- Trisomy 21 (Down syndrome): an extra copy of chromosome 21, the most common chromosome condition at birth and the one NIPT screens for most accurately.
- Trisomy 18 (Edwards syndrome): an extra copy of chromosome 18. Rarer, and screened for on every standard NIPT.
- Trisomy 13 (Patau syndrome): an extra copy of chromosome 13, rarer again, and included as standard.
- Sex chromosome conditions (optional): differences in the number of X or Y chromosomes. These are screened for less precisely than trisomy 21, and you choose at ordering whether to include them.
- Fetal sex (optional): reported from the presence or absence of Y chromosome material. Highly accurate, though not absolutely certain, and entirely your choice.
Who it's for
Anyone who is at least 10 weeks pregnant and wants the most accurate screening available for the common chromosome conditions. It is for adults aged 18 and over. NIPT is offered at any age: a higher chance of trisomy 21 comes with age, but most babies are born to younger women, so screening is not only for women over 35. Twin pregnancies can usually be screened, with some limits on what can be reported. If you have already had a first trimester combined screen, NIPT can still be done.
What you'll learn, and what you won't
You will learn whether your pregnancy has a low or high chance of the conditions screened, reported in plain English rather than raw laboratory numbers, and, if you asked for it, the fetal sex. A blood test is one input to a doctor's assessment, not a diagnosis on its own.
What it will not do is check everything. NIPT does not screen for structural differences such as heart or spine conditions (the 12-week and 20-week ultrasounds do that), it does not screen for inherited conditions such as cystic fibrosis (that is reproductive carrier screening), and it cannot confirm a chromosome condition on its own. Occasionally the sample has too little placental DNA to report. A repeat collection often gives a result, and your doctor reviews you and may offer further testing rather than only collecting again.
The three NIPT tests used in Australia
Harmony, Percept and Generation are the brand names of the screening tests most Australian laboratories run. All three read placental DNA from the same simple blood collection and all three screen for the same three trisomies as standard. What differs is the laboratory that runs the analysis, the optional extras offered, and the turnaround.
| Test | Screens for as standard | Optional extras | Turnaround |
|---|---|---|---|
| Harmony | Trisomy 21, 18 and 13 | Sex chromosome conditions, fetal sex | Usually a few business days from collection |
| Percept | Trisomy 21, 18 and 13, plus a genome-wide screen for other large chromosome changes | Sex chromosome conditions, fetal sex | Usually a few business days from collection |
| Generation | Trisomy 21, 18 and 13 | Sex chromosome conditions, fetal sex | Usually a few business days from collection |
Details vary by laboratory and change over time; your request form and result report name the test used. Prices vary between providers, and there is no Medicare rebate for any of them.
For most women the practical answer is that the choice matters less than getting screened at the right time. If you have a preference, say so when you order and we will tell you what the requesting laboratory offers. Our guide to NIPT costs in Australia compares the three in more detail.
How results are reported and what they mean
NIPT is not reported as a number in a reference range. It is reported as a chance, in one of three ways.
| Result | What the report says | What it usually means |
|---|---|---|
| Low chance | The screened conditions are unlikely in this pregnancy | Reassuring for the conditions screened. It is not a guarantee, and your usual ultrasounds and antenatal care continue. |
| High chance | The result suggests an increased chance of one of the screened conditions | A prompt for the offer of a diagnostic test to confirm or exclude it, arranged through your doctor. It is not a diagnosis. |
| No result | Not enough placental DNA in the sample to report confidently | Often a repeat collection a week or two later gives a result, and no result is more common early in pregnancy and at a higher body weight. Because a no result is slightly more common in affected pregnancies, your doctor also reviews you and may suggest an ultrasound or diagnostic testing. |
Ranges and reporting formats vary by laboratory; your report shows the format your lab uses.
How accurate is NIPT?
For trisomy 21, published studies put the detection rate above 99 in 100 affected pregnancies, with a false-positive rate of around 1 in 2,000. Accuracy is a little lower for trisomies 18 and 13, and lower again for sex chromosome conditions, which is why those are optional.
The number that surprises people is what a high-chance result means in practice. Because these conditions are uncommon, a proportion of high-chance results turn out not to be confirmed on diagnostic testing, and that proportion is higher in younger women and for the rarer conditions. This is normal for a screening test and is exactly why a confirmatory diagnostic test is offered as the next step, rather than anything being decided on the screen alone.
Fetal sex is reported very accurately from about 10 weeks, but it is not 100 per cent certain, and it is confirmed at your morphology ultrasound.
NIPT compared with first trimester combined screening
First trimester combined screening pairs a nuchal translucency ultrasound at 11 to 13 weeks with a blood test, and produces a risk figure for trisomy 21, 18 and 13. It attracts a partial Medicare rebate for both the blood test and the nuchal translucency ultrasound, and the ultrasound also looks at how the pregnancy is developing.
NIPT screens for the same three trisomies far more precisely, but it is self-pay and it does not look at the baby's structure. Many women do both: NIPT for the chromosome question, and the 12-week ultrasound for everything an image can show. Your doctor can tell you what makes sense for your pregnancy.
When to do this test
From 10 weeks of pregnancy, counted from the first day of your last period. Before 10 weeks there is often too little placental DNA in your blood, and the test is more likely to come back without a result.
- Is 12 weeks too early? No. Twelve weeks is a very common time to collect, and the sample quality is usually better than at 10 weeks.
- Is 14 weeks too late? No. NIPT can be done at 14 weeks or later, right through the pregnancy. Later collection simply leaves less time for follow-up testing if a high-chance result comes back.
- Bring your dating scan if you have had one. RANZCOG recommends an ultrasound before NIPT to confirm dates, viability and the number of babies, and accurate dating also confirms you are past 10 weeks.
No fasting is needed and the time of day does not matter.
After a high-chance result
Nothing is decided on a screening result. A KnowLuna doctor contacts you directly, explains what the report says and arranges the referral pathway: diagnostic testing (chorionic villus sampling or amniocentesis) through your obstetrician or GP, and genetic counselling so you have proper support while you decide what you want to do. There is no pressure and no timetable beyond the clinical one.
How it works
- Order online. Either upload the request your own doctor has signed, or a KnowLuna women's health doctor reviews your details and requests the test for you.
- Collect at an accredited centre near you from 10 weeks, or book a nurse home visit (options below). No fasting. Bring your dating scan result if you have one.
- Results are usually ready within a few business days, explained in your account, with a doctor to talk them through. Anything that needs prompt discussion is phoned through.
Choose how you collect
Every option is the same accredited test and the same report. Pick what suits you at checkout; the fee, if any, is added to either pathway price.
A quick draw at an accredited pathology collection centre near you. Usually under ten minutes. Included.
A registered nurse comes to your home or workplace for a standard blood draw. Metro areas of capital cities; other locations on request.
Broader screening from the same draw
Standard NIPT answers the question most women are asking. Two further tests can be added to the same blood sample: genome-wide NIPT, which adds every other whole-chromosome change and the larger deletions and duplications, and single-gene NIPT, which screens for a panel of serious single-gene conditions that arise new in a pregnancy and that chromosome-based NIPT cannot see. RhD negative? The fetal RhD test tells you whether anti-D is needed. A doctor helps you choose; none of them is routine for everyone.
Common questions
How much does NIPT cost in Australia?
Prices vary between providers and by which optional extras you include. There is no Medicare rebate, so it is an out-of-pocket cost wherever you have it. KnowLuna's NIPT is priced at launch, once our laboratory agreement is signed; waitlist members see the price first. Either pathway applies: bring your own doctor's signed request, or have a KnowLuna doctor request it and explain the result in a 20-minute video consult. See our NIPT cost guide.
Is 12 weeks too early for NIPT?
No. NIPT can be collected from 10 weeks, so 12 weeks is comfortably within the window and is one of the most common times to have it. By 12 weeks there is usually plenty of placental DNA in your blood, which slightly reduces the chance of a sample that cannot be reported.
Is 14 weeks too late for NIPT?
No. There is no upper limit: NIPT can be collected at 14 weeks and well beyond. The only practical consideration is time. If a high-chance result comes back, later collection leaves a shorter window for diagnostic testing and for the conversations that follow, so earlier is generally easier.
Is the NIPT gender result 100% accurate?
It is highly accurate from 10 weeks but not absolutely certain. Fetal sex is reported from Y chromosome material in your blood, and occasional discrepancies happen, including in twin pregnancies. Treat it as very reliable information rather than proof, and expect it to be confirmed at your morphology ultrasound.
Is NIPT covered by Medicare?
No. NIPT is not Medicare-rebated in Australia, at any age, so it is self-pay for everyone including women over 35. First trimester combined screening is partly rebated, which is one reason some women do that as well. KnowLuna shows the full price before you order.
What is the difference between Harmony, Percept and Generation?
They are different brand-name versions of the same kind of screening test, run by different laboratories. All three screen for trisomy 21, 18 and 13 from a single blood collection, and all three offer fetal sex and sex chromosome conditions as options. Turnaround, optional extras and price differ; accuracy for trisomy 21 is comparable.
Sources and further reading
- Pathology Tests Explained (RCPA): NIPT (non-invasive prenatal testing)
- RANZCOG: Prenatal screening and diagnostic testing for fetal chromosomal and genetic conditions (C-Obs 59)
- Gil MM et al. Analysis of cell-free DNA in maternal blood in screening for aneuploidies: updated meta-analysis. Ultrasound Obstet Gynecol 2017
- Pregnancy, Birth and Baby: non-invasive prenatal testing (NIPT)
- Pregnancy, Birth and Baby: screening for Down syndrome
- Better Health Channel: chorionic villus sampling
General information only, not medical advice. A test result is one input to a doctor's assessment, not a diagnosis on its own, and every abnormal result is followed up by a KnowLuna doctor. If your symptoms are severe or sudden, see a doctor promptly. Read our medical disclaimer.
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