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

Pregnancy is the most important journey we all want to live to the fullest. This is a journey full of emotions, be it excitement, nervousness, or fear, we face it all very bravely just to hold our baby in our arms.

All of us want to make very informed healthcare decisions for our unborn child and protect their health. 

The NT NB Scan (nuchal translucency nasal bone) is an essential part of prenatal care. Confused about it? Don’t worry, this blog is going to clear all your doubts and will keep you in a position where you will be able to make an informed decision.

Introduction to NT NB Scan in Pregnancy

To explain it in simple terms – The NT NB scan, full form – Nuchal Translucency and Nasal Bone scan is a very important prenatal screening test. It is performed during the first trimester of pregnancy (usually between 11 to 14 weeks). 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?

As we already stated above, assessing your baby’s chance of developing specific chromosomal abnormalities, such as Down syndrome and Trisomy 18, is the main goal of an NT/NB scan.

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.

This test is important for:

• 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?

You are now aware that the NT NB scan is a routine ultrasound performed between 11 and 14 weeks of pregnancy to assess the baby’s risk for chromosomal abnormalities. Here’s what you can expect during the procedure:

1. Preparation for the Scan

• There is no special preparation required, 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

• A transabdominal ultrasound (gel applied on the belly) is commonly used.
• In some cases, a transvaginal ultrasound may be needed for better visualization.
• The sonographer will measure:
  • Nuchal Translucency (NT): The fluid-filled space at the back of the baby’s neck.
  • Nasal Bone (NB): Presence and development of the nasal bone.
• The procedure is painless and takes about 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)

Understanding NT NB Scan Report

The NT NB (Nuchal Translucency & Nasal Bone) scan report helps assess the 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 cost of an NT NB scan in India varies based on the diagnostic center, city, and facility type. On average, the price ranges between ₹2000 and ₹4,100. Private hospitals and high-end diagnostic centers may charge more, while government hospitals and smaller clinics typically offer lower prices.

Additional factors like the use of advanced ultrasound technology or package inclusions can also affect the cost. It is advisable to check with local diagnostic centers for exact pricing.

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 screening tool that helps assess the likelihood of certain chromosomal conditions. It does not provide a diagnosis but helps determine if further testing is needed. Consulting a doctor is essential for understanding the results and deciding the next steps.

If you are looking for expert care and an affordable price for the NT NB scan in Patna, reach out to our team At Diwya Vatsalya Mamta IVF. We provide world-class diagnostics and personalised care to make your pregnancy journey.

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

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