What a wonderful image of a bright, healthy future. This is the picture used by a manufacturer of a Non-Invasive Prenatal Test (NIPT) which seemingly offers a 100% accurate, risk-free test for detecting Down syndrome. This is what it says on the packaging.

Life is full of surprises but it's always difficult to accept them when you have been told otherwise. However, NIPT is not 100% accurate and detects 99 out of 100 foetuses with Down syndrome and therefore misses 1 in a 100 cases. This is the reality of NIPT.


My name is Karolina and I am a GP in Denmark. In 2015, I underwent a NIPT test which eliminated any risk of Trisomy 21 (Down syndrome) in my baby. Six months later, I gave birth to my daughter Helene, who was diagnosed with Down syndrome. It seems there are more cases like this in Denmark and across Europe. And there will be many more because NIPT tests are becoming part of refundable national prenatal programmes in increasingly more EU countries.

This is why I decided to set up an association together with other mothers across Europe who took the NIPT test and obtained a false result. We plan to inform future parents about the way the test works and the real accuracy of non-invasive prenatal tests. We do not question the need for conducting NIPT tests, but we do wish for parents to be able to make informed decisions that take into consideration the fact that these tests do not give the same levels of certainty as invasive tests. We are ready to honestly and openly discuss the results of our tests, our experiences and the information we have collected.

We are convinced that all parents like us hope, above all else, to give birth to healthy children. We have been ready to undertake all the best possible and recommended procedures to guarantee this. We have put our trust in the assurances of the NIPT test manufacturers as well as our doctors, often pulling out of invasive tests in favour of NIPT believing that we will receive equally reliable results. However, that has not been the case and the number of people in our group clearly demonstrates that the risk of not detecting Trisomy 21 via the NIPT test is far greater than attested by some manufacturers. A false negative NIPT has deprived us of the possibility of taking an informed decision as to our future motherhood and the need to prepare ourselves for bringing a child into this world burdened with Trisomy. Our hopes for a healthy child, hopes and plans for our life and ambitions for the future have been destroyed. Our lives now revolve solely around having to bring up a child with Down syndrome and feeling deprived of all hope and being left without any help and care by the manufacturers of NIPT. We are too scared even to think what is going to be when we will no longer be here to support our children.


Non-Invasive Prenatal Testing (NIPT), also termed Non-Invasive Prenatal Screening (NIPS), is successfully making its way across Europe and elsewhere to become a part of state-funded prenatal screening.

So how does NIPT actually work?

NIPT is a simple blood test like any other blood test. During pregnancy cell-free fetal DNA (cffDNA) are in the mother's blood. CffDNA originates from the trophoblasts making up the placenta. By counting the baby's DNA fragments, we can project how many copies of chromosome 21 there are.

Nowadays, NIPT is used predominantly as secondary screening test to calculate the risk of Trisomy 21 (Down syndrome). It can also calculate the risk of Trisomy 13 (Patau Syndrome) and Trisomy 18 (Edwards Syndrome) as well as detect sex of the foetus.

Does NIPT put the foetus at risk?

As a non-invasive screening test, the blood test holds no risk to the pregnancy.

For some NIPT manufacturers this is actually the test’s main selling point.

Invasive diagnostic tests such as amniocentesis or chorionic villus sampling (CVS) are accurate but carry a 1-2% risk of miscarriage (according to the manufacturer of NIFTY test).

We are all more or less anxious when it comes to invasive diagnostics such as amniocentesis or CVS. However, for example the manufacturer of NIFTY test has made it a point within their marketing campaign to feed the flames of this anxiety by accentuating the risk of miscarriage associated with invasive diagnostics.

According to the most recent studies however, the risk is actually much lower and stands at only 0.11%. Furthermore, it is primarily associated with “the same components of combined screening that lead to an increased risk for fetal aneuploidies and therefore uptake of CVS, such as an increased fetal nuchal translucency and decreased maternal serum pregnancy associated plasma protein-A (PAPP-A), are also associated with an increased risk for miscarriage and stillbirth. Caroline Ogilvie and Ranjit Akolekar, Pregnancy Loss Following Amniocentesis or CVS Sampling—Time for a Reassessment of Risk; Dr. P. Wegrzyn, Opinion to RCOG, Non-invasive prenatal testing for chromosomal abnormality using maternal plasma DNA, Scientific Paper No. 15, March 2014

How sensitive is NIPT?

  • This depends on the manufacturer, but some claim sensitivity of almost 100% in pregnant women with a higher risk identified.
  • According to the manufacturers of NIPT, the risk of a false negative test result is one percent or less. In other words, out of 100 babies with Trisomy 21 the test will detect a minimum of 99 and miss a maximum of 1.
  • On average, in one percent NIPT gives a false positive, i.e.: when 100 women have this test, one woman will be told there is an increased risk of Trisomy 21, whereas the baby does not have Trisomy 21.

The fact that cffDNA originates from the placenta may affect the test’s accuracy.

Who should use NIPT?

Common experience tells us that if the ultrasound shows abnormalities in the baby (including, in our cases, nuchal thickness of >3 mm) you should undergo invasive diagnostics such as amniocentesis. NIPT is not non-invasive or miscarriage risk-free, thus safer alternative to the completely-reliable invasive diagnostic amniocentesis. Questions then arise for whom is NIPT actually designed, if not for high-risk pregnancies?

Currently NIPT can be considered in the following situations:

  • you had a combined test which shows an increased risk of Trisomy 21 (where increased does not mean high-risk);
  • you are 35 (some manufacturers would indicate 40) or older and therefore have an increased risk of having a baby with Trisomy 21,
  • you are extremely concerned and want as much certainty as possible about Trisomy 21 in a non-invasive way;
  • your anxiety about amniocentesis or CVS and the associated risk of misscarriage is so great that you are ready to accept that you can become one of the cases where NIPT does not detect Trisomy 21.

NIPT is not recommended:

  • in case of multiple pregnancies, not including twin pregnancies;
  • if you (the mother) has had a blood transfusion, a transplant, stem cell or immunotherapy over the past three months, or ongoing heparin therapy;
  • in case of abnormalities in your genetic material or in the father’s.

An invasive test is recommended by some reliable manufacturers:

  • if the ultrasound shows abnormalities in the baby (including nuchal thickness of > 3.5 mm according to reliable test manufacturers, or in our cases >3mm);
  • if you (the mother) suffer from serious obesity (with a BMI of 30 and more).

What are the limitations of NIPT?

The following disorders may not always be detected by NIPT:

  • mosaicism of chromosome 21, and
  • small abnormalities (deletions or duplications) of chromosome 21.


NIPT is not a diagnostic test. Its results are based merely on statistical risk calculations. Therefore, NIPT will not offer you yes or not answer. Instead, NIPT, as any other prenatal screenings, will provide you with a risk score.

NIPT shows a low risk

This means that no indications have been found for the presence of an extra copy of chromosome 21.

A low-risk NIPT result cannot exclude Trisomy 21 100%. A market standard for the available NIPT tests is that out of 100 foetuses with Trisomy 21, NIPT detects a minimum of 99 and misses a maximum of one.

Our own NIPT low-risk scores for Trisomy 21 ranged from 1:1696661 to 1:4738. They were considered conclusive, and no genetic follow-up was recommended. Even so, six months after conducting NIPT we gave birth to children with Down syndrome.

NIPT shows a high risk

This is a strong indication, but does not necessarily mean the foetus has Trisomy 21. When NIPT shows an abnormal number of chromosome 21, the result needs to be confirmed by an invasive test: chorionic villus sampling or an amniocentesis.

This additional diagnostic test provides direct information about the foetus' genetic material, which is the only way to say with certainty whether the foetus has Trisomy 21.

NIPT is unclear or failed

This occurs in three to five percent of tests. NIPT fails, which means the test cannot determine your personal risk of a foetus with Trisomy 21. This is mainly due to insufficient foetal DNA in your blood. This is for instance possible if the blood test is taken too early (depending on a given test before 10-12 weeks), but also if you are obese. Some therapies, e.g. heparin therapy, can influence the quality of the test.

In summary, if you have your prenatal screening conducted with a view to confirming certain abnormalities beyond any doubt, especially when some Trisomy indicators such as high nuchal thickness are identified during ultrasound, NIPT is not for you. Even if you use the test, you should not rely solely on its results. Remember, these are only statistics, and you should know for sure. Don’t take the chance.


Due to some initial indications of Trisomy 21 (Down’s syndrome) identified during the first trimester screening (nuchal thickness of >3 mm), each of us were referred by our doctors to undergo genetic testing or specifically state-funded amniocentesis. However, when we called upon our geneticists we were persuaded to conduct a NIPT test instead. In each case the test offered negative results (low-risk) and the test’s manufacturer did not recommend any further diagnostic tests to reconfirm the results. On the contrary, the test’s manufacturer expressly advised its clients to conduct an invasive procedure only to confirm whether an identified condition exists (positive test results).

The test we used is being sold as a next generation leading genetic test which offered an equally effective method to amniocentesis but was non-invasive in order to detect whether or not the foetus had Down syndrome. According to available information, the test identified all foetuses with Down syndrome and no case of a false-negative had ever been identified.

We were overjoyed to hear that medical science had developed so fast over recent years and that it offered safe solutions which allowed for detecting trisomic abnormalities without entailing any risk of miscarriage. As most mothers-to-be we had only one major consideration after becoming pregnant, that was to bear a healthy child. So we spared no expense in ensuring this could happen through what seemed to be the perfect solution: a non-invasive genetic test of cff-DNA.

There were a number of fine-print disclaimers included in the consent form. We were told that such disclaimers should merely be considered as standard contractual language of no practical importance to us. In a worst case scenario, we were made to believe that we would only have to undergo amniocentesis if the test result was positive.

In each case, NIPT offered low-risk results as regards the risk of Trisomy 21 ranging from 1:1696661 to 1:4738. Only one of the test results was provided along with notes and recommendations in our native language (which was not English).

NIPT was believed by us and our gynaecologists/obstetricians to be conclusive for the purpose of ruling out any risk of abnormalities; we were assured that the pregnancies were proceeding well. We were told that we should not be worried. As the results were titled: “Non-invasive prenatal genetic test” we felt comfortable about the results and considered them conclusive.

We had our regular second and third trimester check-ups and screenings. They did not reveal any abnormalities. Each of us expected to have a healthy child.

However, several months later each one of us gave birth to a child which was diagnosed postnatally with Trisomy 21 (Down syndrome).

In each case, owing to the disability, the delivery was a lengthy, life-threatening procedure, which none of us nor the obstetrical clinic staff foresaw, nor were prepared for.

We suffered the greatest shock of our lives on hearing the diagnosis. What is more, in the first days of our new-born children lives, they required intensive care, and one of them had to be rushed from the obstetrical clinic to a distant hospital with an intensive care unit. The lack of skin-to-skin contact led to each of us not being able to breastfeed.

The first instances of false-negative results were immediately reported to the test manufacturer’s associated service providers. Nevertheless, the test manufacturer failed to warn its associated service providers and the general public including potential customers, of recording of the false-negative results. The test quality characteristics such as sensitivity and specificity were not duly updated in the information package available online.

Having been asked to explain why the test failed to detect Trisomy 21, the test manufacturer’s associated service providers informed us that the test results could have been affected by placental mosaicism. However, we were not advised beforehand to secure the placental samples for the purpose of postnatal testing in the case of the false negative results.

Our children suffered, among others, from hypothyroidism. Later they were diagnosed with dysplasia of the hip which eventually affected their knee joints. After being discharged from hospital, our children have required regular medical monitoring and extra around-the-clock care. In particular, they have required regular medical assistance and physiotherapy:
  1. medical check-ups (orthopaedist, audiologist, ophthalmologist, physiotherapist, geneticist, endocrinologist, cardiologist and ENT);
  2. detailed blood tests (impaired functioning of the immune system, high risk of leukaemia);
  3. motoric physiotherapy;
  4. neurological speech therapy (facial massage, eating, drinking, swallowing, chewing);
  5. psychologist;
  6. sensory integration therapy;
  7. pet therapy;
  8. swimming sessions.
Our children learn and progress much slower than other children. In particular, they:
  1. first sat at the age of 18 months;
  2. learnt to walk when they were two and a half;
  3. cannot walk up and down the stairs, jump, run, walk long distances;
  4. cannot speak (only simple words such as mama and papa).
To be able to cope with the added needs of a disabled child, some of us had to quit our jobs.

We believe that the business model of one of the NIPT manufacturers in which it is labelled as a leading ‘next generation’ product and positioned as a genetic diagnostic test, and competes in common medical prenatal practice with invasive cytogenetic diagnostic testing, especially amniocentesis is simply inaccurate and dishonest.

NIFTY is “a non-invasive prenatal genetic test […]. The good results of NIFTY allows you to skip invasive procedures (including amniocentesis) which mothers-to-be are so anxious about […]”. NIFTY “is the most reliable, the most used non-invasive prenatal genetic test in the world.”

NIPT is merely a screening test while diagnostic amniocentesis alongside other invasive diagnostics is the only way to obtain an accurate diagnosis of the presence of genetic disorders.

It goes without saying that a non-invasive diagnostic test which offers the same accuracy as invasive cytogenetic testing with no risk of miscarriage would be the perfect product for expecting parents, allowing them to have a problem-free pregnancy and a healthy child. Such product, however, does not exist at the moment.

One of the manufacturers does not publicise the fact that six false negative cases of T21 were identified during the validation study conducted and published by a team led by Mr. H. Zang (Non-invasive prenatal testing for Trisomies 21, 18 and 13: clinical experience from 146,958 pregnancies). What is more, we believe that there may have been more than six cases as out of 146,958 tests they returned as many as 33,099 cases (nearly 23%) which had no outcome data because contact with these patients was lost or interviews were declined. The most important statistic as regards the accuracy of NIPT was not even highlighted in Mr. H. Zang’s study itself. Namely the study revealed that NIPT detected 726 cases of T21 validated by either karyotyping or a postnatal follow-up. When compared to the six false negative cases of T21 identified as part of the NIPT validation study, this gives a 0.82% false negative results rate. Effectively, this means that NIPT failed to detect 1 in every 122 cases of Trisomy 21 identified during the validation study based on the available outcome data (only 77% tests returned such data).


If you want to learn more, share your experiences or become part of our initiative, feel free to contact us.