Everything you need to know about NIPT

Sponsored by Fostertest.se

With the wonderful news of a baby on the way, most parents-to-be can be challenged by feelings of anxiety and patience. Many ask themselves if they are really pregnant and want to know that the baby in their belly is healthy and doing well. By doing NIPT via a simple blood test, you can get guidance on these questions already in the first trimester.

You are about to embark on the biggest journey many people ever take: the journey to becoming a parent. It can feel amazing, scary, difficult and wonderful all at the same time, especially in the early days before you know more about the pregnancy and the fetus in your belly. NIPT can be done as early as week 11 (10+0) to find out the likelihood of whether the baby you are expecting has any of the most common chromosomal abnormalities.
Harmony NIPT

What is NIPT?

During pregnancy, the mother's blood contains short fragments of DNA from the fetus/ placenta. By taking a blood sample from the mother and analyzing the DNA, the relationship between the different chromosomes is compared. Before the blood test, the pregnant woman should have an ultrasound scan to confirm the gestational week and the number of fetuses. This is often offered at the same clinic where the blood sample is taken. NIPT is a safe and accurate form of prenatal diagnosis to determine the likelihood of the most common chromosomal abnormalities.

Trisomies mean that there are three, rather than two, copies of a chromosome. The one most people are familiar with, and the most common, is trisomy 21, which leads to Down syndrome. Less common are trisomy 13 (Patau syndrome) and trisomy 18 (Edwards syndrome), both of which cause very severe mental retardation and severe birth defects.

NIPT or KUB? How do they differ and how reliable are they?

Both NIPT and KUB are performed on blood samples with the common aim of assessing the likelihood of the most common chromosomal abnormalities. The major difference is that NIPT is a targeted test that directly analyzes the fetal chromosomes. Harmony NIPT finds 99% of all chromosomal abnormalities included in the analysis, with a positive test result (high probability of chromosomal abnormality) for trisomy 13, 18 and 21 being true in 70 - 90% of cases.

KUB measures the concentration of specific pregnancy hormones, which together with the mother's age and an ultrasound (which measures the width of the cleft in the fetal neck) gives a probability of chromosomal abnormality. KUB is not as reliable, finding 85% of all chromosomal abnormalities, with a positive test result only being correct in 3 - 10% of cases. Harmony NIPT therefore produces about 70 times fewer false positives!

KUB is possible between weeks 11 and 14, while NIPT can be done from week 10 and has no maximum limit. Unlike KUB, Harmony NIPT can also analyze for sex chromosome abnormalities and find out the sex of the fetus.

Who can do NIPT and where can I do the test?

As an expectant mother, it is always up to you to decide whether or not you want to undergo prenatal diagnosis. Depending on the region you live in and your age, public health services may not offer you prenatal diagnosis. If your age is known, in most regions you will be offered KUB as a first test. If the KUB shows an increased probability, a second test in the form of NIPT or invasive tests may be offered.

Because KUB does not find as many chromosomal abnormalities, and at the same time gives many false test results, it does not provide the same security as a NIPT result. Therefore, many people choose to do NIPT directly. This is then done at private midwife or doctor's clinics. At Fostertest.se you can easily use the map feature to find where you can do Harmony NIPT.

Is there a difference between NIPT and NIPT? Why should I choose Harmony NIPT?

There are several different brands of NIPT. The specificity and sensitivity of the tests differ between brands. Harmony NIPT has high specificity, resulting in 12 times fewer false positives compared to some other brands of NIPT. Harmony is the most widely studied brand with nearly three million tests performed globally. When a test result is negative (low probability of chromosomal abnormality), it is correct in more than 99.99% of cases. No further testing is recommended.

Sex chromosome abnormalities (abnormalities on the X and Y chromosomes) are a free option for Harmony NIPT, an analysis not offered by all other NIPT brands. In addition, unlike some other brands, Harmony always measures the fetal fraction, to ensure that the blood sample actually contains enough DNA from the fetus. This is an important quality step. The difference between NIPT and NIPT is therefore significant.

What is fetal fraction?

Fetal fraction is the ratio of DNA from the fetus to the woman present in the blood sample. The fetal fraction generally increases during pregnancy and varies depending on several parameters such as ongoing infection, body weight and biologically between different pregnant women.

In the case of a low fetal fraction, this means that the blood sample simply does not contain enough DNA from the fetus to give a reliable result. For those NIPT techniques that lack this important quality step, the result can only reflect the mother's own chromosomes. As a result, results are often given on the false basis that a healthy girl is expected. For Harmony NIPT, which measures fetal fraction, this means that in about 4% of cases a free retest needs to be done within two weeks to provide a reliable result.

What do I do if there is a likelihood of a chromosomal abnormality?

If the NIPT shows a high probability of chromosomal abnormalities, it is up to the parents to decide how to proceed. The healthcare professional who prescribed the NIPT will advise you and explain your options. The first step is usually to confirm the result via invasive sampling, i.e. amniocentesis or placenta sampling.

Amniocentesis involves inserting a needle into the uterus via the stomach and sucking out some water to obtain cells and other genetic information about the fetus. The placenta test works in a similar way, where tissue is extracted from the placenta. With both of these tests comes an increased risk of miscarriage. It is then entirely up to the pregnant woman and her partner, if any, to decide what to do with the information, with the help of health professionals along the way.

Life Genomics is the largest private NIPT lab in the Nordic region and has offered NIPT since 2015. The analysis is performed at a clinical laboratory in Gothenburg, accredited by the national accreditation body Swedac. The accreditation provides increased security and ensures that the analysis meets the high quality requirements. Life Genomics works closely with the Swiss company Roche Diagnostics, which developed Harmony NIPT. Sampling always takes place at selected midwife or doctor's clinics, where blood samples are then sent to Life Genomics.

Book an appointment for Harmony NIPT HERE!