11–14 Week Aneuploidy Screening in Nagpur
A clinically structured first-trimester screening assessment for trisomy 21, trisomy 18 and trisomy 13 risk — combining precise ultrasound markers, maternal factors and biochemical markers where indicated.
What is 11–14 week aneuploidy screening?
11–14 week aneuploidy screening is a first-trimester risk assessment performed during the short window when the fetal crown-rump length is between 45 mm and 84 mm. It estimates the chance of common chromosomal conditions, especially trisomy 21, trisomy 18 and trisomy 13.
This page is written slightly more clinically than the general NT scan page. The NT scan focuses mainly on patient understanding. This aneuploidy screening page explains the complete clinical framework: ultrasound markers, maternal factors, biochemical markers, risk calculation, interpretation and follow-up pathways.
The screening window is strict
The 11–14 week scan is not just an early pregnancy scan. It is a time-sensitive measurement-based screening protocol. Outside this window, NT-based risk calculation is no longer valid in the same way.
Core components of 11–14 week aneuploidy screening
A complete first-trimester screening assessment does not depend on a single number. Dr. Kunda Shahane integrates multiple markers to create a clinically meaningful risk interpretation.
| Component | What is evaluated | Clinical significance |
|---|---|---|
| Crown-rump length | Accurate fetal length measurement from head to rump. | Confirms gestational age and validates whether NT screening is technically eligible. |
| Nuchal translucency | Fluid space behind the fetal neck measured in a strict mid-sagittal plane. | Increased NT may raise risk for chromosomal conditions and some structural concerns. |
| Nasal bone | Presence or absence of the fetal nasal bone when technically assessable. | Used as an additional marker in first-trimester aneuploidy risk assessment. |
| Ductus venosus flow | Waveform pattern in the ductus venosus, especially the a-wave. | Abnormal flow may refine risk and may also prompt careful cardiac follow-up. |
| Tricuspid flow | Assessment for tricuspid regurgitation when fetal position permits. | Can contribute to first-trimester risk refinement in selected cases. |
| Maternal age and background risk | Age-related baseline risk and relevant medical/pregnancy history. | Forms the starting point before ultrasound and blood marker adjustment. |
| Biochemical markers | PAPP-A and free beta-hCG blood test where combined screening is chosen. | Improves screening performance compared with NT measurement alone. |
| Early anatomy review | Early review of fetal head, abdominal wall, limbs, stomach, bladder and gross anatomy. | Does not replace the 18–22 week anomaly scan, but can detect some early concerns. |
This is a screening assessment. A low-risk result is reassuring but not a guarantee. A high-risk result does not confirm a condition. It indicates the need for counselling and possible further testing.
How this differs from NT scan, combined screening and NIPT
These terms often overlap in patient conversations. The difference is important, especially when explaining results or planning further testing.
NT Scan
- Ultrasound-based first-trimester scan
- Measures nuchal translucency
- Also checks CRL and early anatomy
- Can be part of wider aneuploidy screening
Combined Screening
- NT scan plus maternal blood markers
- Uses PAPP-A and free beta-hCG
- Creates a combined risk estimate
- Useful when blood test is done in the correct window
NIPT
- Maternal blood test using cell-free fetal DNA
- Higher screening accuracy for common trisomies
- Still a screening test, not diagnostic confirmation
- Often discussed after intermediate or high-risk results
CVS / Amniocentesis
- Diagnostic tests, not screening tests
- Recommended after counselling in selected cases
- Can provide chromosomal confirmation
- Performed only after informed consent
Indications for 11–14 week aneuploidy screening
This screening is recommended as part of routine first-trimester care for most pregnancies. It becomes especially important when the pregnancy already has maternal, fetal or family-history risk factors.
What happens during the appointment?
GE Voluson Signature Expert for precise first-trimester imaging
First-trimester screening depends on small measurements and correct imaging planes. At Mayflower, the GE Voluson Signature Expert supports high-resolution fetal imaging, standardized views and consistent documentation. Technology supports the doctor’s expertise — it does not replace clinical judgement.
What can the result mean?
| Result category | Meaning | Possible next step |
|---|---|---|
| Low risk | The calculated risk is below the threshold used for further testing. This is reassuring but does not guarantee absence of all conditions. | Continue routine antenatal care, anomaly scan at 18–22 weeks and follow-up as advised. |
| Intermediate risk | Risk is not clearly low, but may not directly require invasive testing. Individual counselling is important. | Discuss NIPT, repeat review, early anomaly assessment or genetic counselling depending on the full picture. |
| High risk | The calculated risk is above the screening threshold. This is not a diagnosis. | Genetic counselling and discussion of diagnostic tests such as CVS or amniocentesis may be advised. |
| Increased NT | NT is above the expected range for CRL. This may be associated with chromosomal, cardiac or other fetal concerns. | Detailed counselling, NIPT or diagnostic testing, early anomaly scan, fetal echocardiography and follow-up plan. |
The most useful report explains the risk, the limitations, the next options and the timing of follow-up. At Mayflower, counselling is part of the assessment, not an afterthought.
How should patients prepare?
Useful internal links for this pathway
These pages support the complete first-trimester screening and follow-up pathway.
Frequently asked questions
Is 11–14 week aneuploidy screening compulsory?
Is this page different from the NT scan page?
Can this test diagnose Down syndrome?
What happens if my result is high risk?
Can twins undergo this screening?
Is blood test always required?
Does a low-risk result mean everything is normal?
Should I bring my obstetrician’s referral?
Fetal Medicine Specialist, Mayflower Fetal Medicine & High-Risk Pregnancy Centre
Book 11–14 Week Aneuploidy Screening in Nagpur
For accurate timing, FMF-standard scan technique and specialist counselling, book your first-trimester screening appointment at Mayflower Fetal Medicine & High-Risk Pregnancy Centre, Dhantoli, Nagpur.
Mayflower Fetal Medicine Centre strictly complies with the Pre-Conception and Pre-Natal Diagnostic Techniques (Prohibition of Sex Selection) Act, 1994. Sex determination and sex-selective practices are strictly prohibited and punishable by law. All ultrasound and prenatal diagnostic services at this centre are performed exclusively for lawful medical indications — fetal anatomy assessment, fetal wellbeing, and diagnosis of maternal-fetal conditions. Disclosure of fetal sex is illegal and is not performed at this centre under any circumstances.
This page is for general patient education only and does not constitute medical advice, diagnosis or treatment. Please consult Dr. Kunda Shahane or your treating obstetrician for advice specific to your pregnancy. Screening tests estimate risk and do not guarantee complete absence of chromosomal, genetic or structural conditions.
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