An introduction to NT Scan Report

The nuchal translucency ultrasound or NT Scan Report may sound like something out of a science fiction movie, but it’s not. It is a routine prenatal test that helps your doctor determine your baby’s risk of having a chromosomal difference. Whether you have announced the good news of being pregnant, trust us, things are going to be serious, mama-to-be!

Your and your baby’s health will be carefully scrutinized for the next nine months, which will include a few prenatal screening tests, scans, and tests.

The nuchal translucency ultrasound is one such screening, which sounds slightly scary and can be a big slice. But don’t fret, the NT scan is a completely safe, routine evaluation — and we’ll go over the whats, whens, whos, and whys here.

What is a Nuchal Translucency ultrasound?

An ultrasound that detects nuchal translucency, is usually carried out between 11.5 and 13 weeks and 6 days of gestation. The main objective of the NT screening determines the likelihood that your unborn child will have specific chromosomal abnormalities (Trisomy 13, 18, and 21).

This examination combines specific blood tests with a nuchal translucency ultrasound.

This risk assessment can also be provided by nuchal translucency ultrasound on its own, but it is not as accurate as combined first-trimester screening. The combined first-trimester screening does not involve inserting needles into the placenta or amniotic sac, unlike other methods of risk assessment.

Combination screening during the first trimester is only a “screening” test. Therefore, combined first-trimester screening only serves to inform us of how high or low your risk is.

What does Nuchal Translucency mean?

The fluid at the back of your baby’s head and neck, just beneath the skin, is called a nuchal translucency. The nuchal translucency (or NT) measurement is a method for accurately determining the fluid’s thickness. Normally, there isn’t much fluid present, which results in a thin NT measurement.

Under specific circumstances, the fluid content can rise, resulting in a thicker NT measurement. Several chromosome abnormalities, such as trisomy 13, 18, and 21, and some structural issues are linked to increased NT measurements (for example, heart abnormalities).

Although a higher NT measurement does raise the risk, it does not always indicate that the baby has a problem.


Your gynacologist might ask you to come back for additional pictures later in the day if your baby is not cooperating and the NT cannot be measured precisely. Patients may need to come back another day if the baby continues to be in an unhelpful position.

How is the NT test performed?

Transabdominal ultrasound is used to perform a nuchal translucency ultrasound.
An ultrasound scan of your lower abdomen is done trans abdominally. The lower abdomen’s skin is covered with a small amount of ultrasound gel, which is then scanned by the ultrasound probe. The gel enhances the probe’s ability to make contact with your skin.

There are times when a transvaginal ultrasound is also required. Your fetal medicine expert who is also an experienced sonographer from a reliable fetal medical center will examine your baby, ovaries, or cervix up close.

Transvaginal ultrasound refers to transvaginal ultrasound. Using an ultrasound probe positioned in the vagina, the area is scanned. The transvaginal ultrasound procedure is typically less painful than a pap smear. This ultrasound doesn’t require any anesthesia.

During your ultrasound, especially the transvaginal exam, your privacy will always be respected. You will wear a gown and a large towel will cover your lower body.

Is a full bladder required for an accurate NT scan report?

Your fetal medicine specialist will typically get better images during transabdominal ultrasound if the bladder is partially filled, so it is advised that you drink water before the examination.

Please try not to empty your bladder again until after your appointment, after which you should drink two glasses of water.

A full bladder causes the bowel to move from the pelvis into the abdomen, making the uterus, cervix, and pregnancy easier to visualize.

Your bladder shouldn’t be so uncomfortably full. You should empty a small amount of urine from your bladder if it is extremely full and painful in order to feel better.

After the transabdominal ultrasound is finished and before the transvaginal ultrasound starts, you will be able to urinate.

Which is best? NT scan with or without food for a better scan report.

There is no need to keep your stomach empty; instead, eat a light meal. Because it is a transabdominal scan, just ensuring that your urinary bladder is full is enough.

How to check and read NT scan report?

The NT test report is a compilation of basic details like maternal weight, gestation period, and gravida (refers to the no of pregnancies the mother has had). To understand in detail how to read the NT scan report, click here.

The report will also draw inferences from other intricate details like Diabetes Mellitus and Chronic Hypertension.

However, the findings will primarily focus on Fetal Heart Activity, Fetal Heart Rate, Crown-rump Length (CRL), Nuchal Translucency (NT), Biparietal Diameter (BPD), Ductus Venoscus PI, Placenta, and Amniotic Fluid.

It also has data about Chromosomal Markers, with detailed information about the Nasal Bone, Tricuspic Doppler, and The Fetal Anatomy including skull and brain, spine, heart, abdominal wall, stomach, bladder/kidneys, and spontaneous limb movements too.

The fetal heart rate, neck thickness (NT), nasal bone, blood flow, and finally the finding that “the baby is normal – no abnormalities seen” should be your top concerns as an expectant mother.

NT scan report sample

NT scan report sample

How accurate is the NT scan report?

Approximately eight out of every ten infants with Down’s syndrome are detected by the nuchal scan alone.

Even though the likelihood of a baby having Down’s syndrome is small, a scan may occasionally indicate that the likelihood is higher. A false positive is an example of this.

For an NT scan, there are 5% false-positive results. Accordingly, one woman out of every 20 receives a high-chance calculation that is incorrect.

A blood test and an NT scan together produce a more precise result. The free beta-hCG hormone and the PAPP-A protein are both detected in the blood test. Down’s syndrome babies typically have low PAPP-A levels and high hCG levels.

Nine out of ten babies are detected when the NT scan is combined with this blood test. This is often referred to as a combined test.

How is the risk calculated in the NT scan report?

A deeper understanding of the NT scan Report measurement and NT Scan Report Analysis is here.

Based on information from the Foetal Medicine Foundation, a special computer program is used to calculate each risk assessment. Nuchal translucency measurements should not be taken in isolation while calculating the risk level.

It has recently been advised that risks at first-trimester screening be divided into one of two categories:

NT scan risks

Your report will include a “background risk” as well as an “adjusted risk.” Your risks for trisomy 13, 18, and 21 will be calculated.

The “background risk” is the starting point for calculating this baby’s individual risk. It is determined primarily by the mother’s age and the baby’s gestational age. If you had a previous baby with a chromosome abnormality, your background risk in subsequent pregnancies may be increased.

The background risk will be shown as a “1 in…” risk.

For example, your baseline risk for trisomy 21 could be “1 in 500.” This means that you have a 1 in 500 chance of having a baby with trisomy 21, while you have a 499 in 500 chance of having a baby without trisomy 21.

The “adjusted risk” is the risk for this specific baby, and it will be displayed as a “1 in…” risk. The nuchal translucency measurement and special blood tests are used to calculate it.

If your adjusted risk is less than 1 in 1000, it is considered “low risk.” For instance, 1 in 1250, 1 in 1500, and 1 in 6000. “Low risk” does not imply “zero risk.” A low-risk outcome is reassuring.

If your adjusted risk falls between 1 in 50 and 1 in 1000, you have “intermediate risk.” For instance, 1 in 125, 1 in 350, and 1 in 900. Women at intermediate risk may choose non-invasive prenatal testing (NIPT) such as the Harmony Test.

Some women in the intermediate risk range, on the other hand, may be offered CVS/amniocentesis because of other concerns on their testing (such as nuchal translucency >3.5mm), or they may choose CVS/amniocentesis because they want 100% diagnostic certainty about the baby’s chromosomes.

If your adjusted risk is greater than 1 in 50, it is classified as “high risk.” For instance, 1 in 12, 1 in 25, and 1 in 40. “High risk” does not imply that your baby is in danger.
It is critical to understand that after the combined first-trimester screening, 5% of women (or 1 in 20 women) will have a high-risk result.

Most babies with “high risk” results do not have a chromosome problem, and fortunately, most women who undergo diagnostic testing (CVS or amniocentesis) have normal results (the baby’s chromosomes are normal). We understand that waiting for these final results can be stressful, but for the majority of women, the end result will be reassuring.

What exactly is the fetal nasal bone?

The fetal nasal bone is used in the assessment of aneuploidy risks during first-trimester screening at Advanced Women’s Imaging, which is accredited.

The use of the fetal nasal bone can have a significant impact on the management and outcomes of your pregnancy.

Using the fetal nasal bone could make or break your pregnancy. It could mean the difference between detecting a chromosome problem and missing it. It could mean the difference between having or not having invasive prenatal diagnostic testing (CVS or amniocentesis).

nasal bone

The fetal nasal bone is used to increase the precision of trisomy 21 screening. By increasing trisomy 21 detection from 90% to 93%, it will find more cases of trisomy 21.

NT scan report when baby is normal

For a healthy baby, the normal NT scan measurements should be between 45mm (1.8in) and 84mm in size for an NT of less than 3.5mm to be considered normal (3.3in).

A newborn with an NT of 1.3mm falls into the acceptable range.

The infant’s NT value of 2.9 mm is also within the acceptable range.
The possibility of Down’s syndrome and other chromosomal disorders rises along with the NT.

A baby with an NT of 6mm is more likely to have Down’s syndrome than other chromosomal and cardiovascular disorders. It’s unusual for babies to have this much fluid.

NT scan report when baby is abnormal

Any nuchal translucency that measures more than 3.5 mm on the ultrasound screen would be considered “abnormal.”

High nuchal translucency is one sign of chromosomal variation, but it is not the only one.

There have been cases of “normal” babies with “abnormal” nuchal translucency (higher nuchal fold measurement and no chromosomal abnormalities).

In fact, the likelihood of having a baby with high nuchal translucency but no significant chromosomal differences range from “70% for NT of 3.5-4.4 mm, 50% for NT of 4.5-5.4 mm, 30% for NT of 5.5-6.4 mm, and 15% for NT of 6.5 or more,” according to this study from 2011.

What if nuchal translucency is high in the NT scan report?

There is only a 70% chance that an “abnormal” nuchal translucency is a sign of a chromosomal difference at this stage, so if your baby has a high nuchal translucency, your doctor will probably recommend you have another test.

They might also advise getting a fetal heart scan since some chromosomal diagnoses are linked to cardiac abnormalities.

Even though it might be difficult, try not to worry if your baby does have a high nuchal translucency measurement; this doesn’t always indicate that they will have a chromosomal difference.

Is a high nuchal translucency always indicative of Down syndrome?

No, not always. A high nuchal translucency measurement can be caused by a variety of factors.

Among the causes of increased nuchal translucency are:

  • Parvovirus is an infection that can cause an increase in the nuchal fold measurement of a baby.
  • Birth defects of the heart (ranging from minor to major).
  • Genetic syndromes that are uncommon
  • High blood pressure due to venous congestion

What happens if a problem is discovered by my NT scan?

You’ll need to decide, with the help of your doctor or a fetal medicine expert, whether the results show a high enough risk that you should undergo CVS or amniocentesis to receive a conclusive diagnosis.

You must balance your desire to learn about your unborn child’s condition with the slight possibility that diagnostic testing could result in a miscarriage when making your choice.

If you choose not to have diagnostic testing, you can still learn more about your unborn child’s health and development by having a detailed ultrasound between 18 and 20 weeks of pregnancy, as well as the quad screen, a blood test that is available to all pregnant women starting at 10 weeks of pregnancy.

The “soft markers” of chromosome disorders that this ultrasound can identify include short limbs, a bright dot in the heart, a bright bowel, and specific kidney issues. Additionally, it can search for structural flaws like spina bifida.

What are the benefits of the NT scan report?

An ultrasound at this point in the pregnancy has additional benefits.
Verification of the child’s heartbeat.

Assessment of the pregnancy’s date: The crown-rump length, abbreviated “CRL,” or the length of your infant from top to bottom, will be measured by the fetal medicine expert. Additionally, he or she will gauge the baby’s head size (typically the “BPD” or biparietal diameter). These measurements allow you to estimate the size or gestation of your unborn child.

Review your baby’s physical foundation: Even at this early stage of pregnancy, many parts of your unborn child can already be examined. Most parents are awestruck by the scan’s level of detail. Therefore, the fetal medicine expert will examine your baby’s basic features, such as the head, arms, and legs, as well as the abdominal wall.

Estimation of the number of babies in the womb: This ultrasound identifies multiple pregnancies (like twin pregnancies). The appearance of the placenta and amniotic sacs can be used to determine the type of twins. As pregnancy advances, it becomes more challenging to make a reliable assessment of this crucial factor in twin management.

How to schedule a nuchal scan with Jammi Scans?

Our consultant – a fetal medicine expert is a gynacologist and obstetrician who upon diagnosis may recommend a nuchal scan, at which point our staff will schedule a consultation for you.

Alternatively, you could contact us to schedule a consultation by using our online booking system. The help desk will set up a nuchal scan for you if you require one.

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