NT NB Scan in Pregnancy: A Complete Guide to NT Scan

NT NB scan in pregnancy is one of the important ultrasounds carried out in the first trimester to assess the baby’s growth. It calculates the Nuchal Translucency (NT), a fluid collection behind the baby’s neck, and it checks the Nasal Bone (NB). It can help determine whether there’s a risk of genetic disorders such as Down syndrome.

Dr. Rashmi Prasad and the compassionate staff at Diwya Vatsalya Mamta IVF have helped countless families through their pregnancy journey. You can read about what the NT NB scan blog is, what to expect and why it’s important here, so that you feel that much more informed and assured.

What is NT NB Scan in Pregnancy​

The NT NB scan full form is Nuchal Translucency and Nasal Bone scan. The NT NB scan in pregnancy is a special ultrasound done in the early months of pregnancy, typically between 11 and 14 weeks during the first trimester. It helps assess the risk of chromosomal abnormalities, such as Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), and Patau syndrome (Trisomy 13).

Why is the NT NB Scan Important?

The NT NB scan in pregnancy is a special ultrasound done early in pregnancy to check if the baby might have any genetic problems, like Down syndrome. It is usually performed between 11 and 14 weeks of pregnancy.

1. Nuchal Translucency (NT)

This gauges the amount of fluid in the area behind your baby’s neck. Chromosome abnormalities may be more likely to occur in those with thicker NT measurements.

2. Nasal Bone (NB)

The nasal bone’s existence or absence may also be a sign of possible chromosome problems.

Why This Test Matters

• Early Detection: This test helps you to find any potential genetic disorders early.
• Non-Invasive: A simple ultrasound with no risk to the baby.
• Guides Further Testing: If abnormalities are detected, additional tests like NIPT, CVS, or amniocentesis may be recommended so that you can avoid having further issues.

NT NB Scan Procedure: What to Expect?

The NT NB scan in pregnancy is a routine Ultrasound Sonography performed between 11 and 14 weeks to assess the baby’s risk for chromosomal abnormalities such as Down syndrome. Here’s what you can expect during the procedure:

1. Preparation for the Scan

• No special preparation is required for the NT NB scan, but if you have a moderately full bladder this will improve image clarity.
• You must remember that wearing comfortable clothing can make it easy for the healthcare professional to access the abdomen.

2. During the Scan

• Most commonly used is a transabdominal ultrasound (gel is applied on the belly).
• A transvaginal ultrasound may be required to view the IUD in some cases.
• The sonographer will measure:
  • Nuchal Translucency (NT) – the fluid-filled space at the back of the baby’s neck.
  • Nasal Bone (NB): Nasal bone absent or present and development of the nasal bone.
• The process is pain-free and lasts for approximately 15–30 minutes.

3. After the Scan

• You will receive a report with measurements and risk assessment.
• If results show increased NT thickness or absent NB, your doctor may recommend further tests (e.g., NIPT, CVS, or amniocentesis)

These scans will help to monitor your baby’s health and development at each stage. You can also consult Dr. Rashmi Prasad, the best IVF Specialist Doctor in Patna.

Understanding NT NB Scan Report

The NT NB scan report helps assess your baby’s risk of chromosomal abnormalities during the first trimester (11–14 weeks). Here’s how to interpret the key details:

1. Nuchal Translucency (NT) Measurement

• Normal NT: Less than 3.0 mm (varies by gestational age).
• Increased NT (>3.0 mm): May indicate a higher chance of Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), or heart defects.

2. Nasal Bone (NB) Assessment

• Present Nasal Bone: Suggests a lower likelihood of chromosomal abnormalities.
• Absent or Underdeveloped Nasal Bone: May be linked to genetic conditions but requires further testing for confirmation.

3. Combined Risk Assessment

The NT NB scan is often paired with a maternal blood test (dual marker test) for a more detailed risk evaluation. The report may indicate:

• Low Risk: NT and NB appear within expected ranges.
• High Risk: Increased NT, absent NB, or abnormal blood test results; further tests like NIPT, CVS, or amniocentesis may be suggested.

4. Next Steps

• If the report shows normal values, no additional testing is usually required.
• If concerns arise, the doctor may recommend genetic counselling and more detailed diagnostic tests.

NT NB Scan Price in India

The average NT NB scan cost in India varies from diagnostic centers, city to city and type of facility provided. Cost of NT NB SCAN Cost of NT Scan Normal in India ranges between ₹1500 to ₹4000. Private hospitals and premium diagnostic centers might charge more, while government hospitals and smaller clinics tend to have lower prices.

Other factors, including employing more advanced ultrasound technology or package deals, can also contribute to the cost. Prices vary for local diagnostic centers, so it’s best to call and get an estimate.

Also Read: HSG Test Price: What You Need to Know Before Getting Tested

 NT NB Scan Accuracy and Limitations

Accuracy

The NT NB scan measures fluid at the back of the baby’s neck and checks for the presence of the nasal bone. It helps estimate the likelihood of chromosomal conditions.

• Detection Rate: Around 70–80% when used alone.
• With Blood Tests: Accuracy improves to 85–90%.
• With NIPT: Can reach 99% for certain conditions.

Limitations

• Not a Diagnostic Test: It only indicates probability; further testing is needed for confirmation.
• Time-Sensitive: Performed only between 11–14 weeks of pregnancy.
• Variability in Results: Fetal position, maternal factors, and sonographer skill can affect accuracy.
• False Positives & Negatives: A higher measurement does not always mean a problem, and a normal result does not rule out all issues.

If results suggest increased risk, additional evaluation may be necessary.

Conclusion

The NT NB scan is an early pregnancy test that can determine the risk of specific possible chromosomal disorders. It doesn’t diagnose but rather indicates whether further testing is needed. Visiting a doctor is absolutely necessary for interpreting the results and taking further action.

If you are looking for quality care and reasonable price Place for the NT NB scan in Patna, get in touch with us We have a team of experts At Diwya Vatsalya Mamta IVF, Dr Rashmi Prasad who is a senior Obstetrician and Gynecologist, has helped countless women to enjoy happy and healthy pregnancies with her expert care.

👉 Have questions? Contact Us Today to schedule your NT NB scan!

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