Pregnancy is a beautiful journey, and every parent wants reassurance that their baby is healthy and developing normally. Today, advanced prenatal screening tests—NT Scan, Double Marker, Triple Marker, and Quadruple Marker Tests—help detect chromosomal or genetic risks early, safely, and accurately.
At Shree Diagnostics, Howrah, we provide all marker tests with expert counseling and high-resolution NT Scan, ensuring safe, reliable and timely reports.
What is an NT Scan?
Nuchal Translucency (NT) Scan is an ultrasound performed between 11–14 weeks of pregnancy.
It measures the fluid-filled space at the back of the baby’s neck.
An increased NT value may indicate risk for:
- Down Syndrome (Trisomy 21)
- Trisomy 18
- Trisomy 13
- Congenital heart defects
NT Scan + Marker Test together provide the highest screening accuracy in early pregnancy.
Marker Tests in Pregnancy: Why Are They Important?
Marker tests analyze specific biochemical markers in the mother’s blood to assess the baby’s risk for:
✔ Down Syndrome (Trisomy 21)
✔ Trisomy 18
✔ Trisomy 13
✔ Neural Tube Defects
✔ Genetic abnormalities
✔ Placental function
These tests are non-invasive, safe and recommended during pregnancy.
Types of Marker Tests – Double, Triple & Quadruple Marker Tests
Below is a clear comparison to understand the difference between them:
1. Double Marker Test (First Trimester Screening)
When done: 10–14 weeks
Combined with: NT Scan
Markers tested:
- Free Beta-hCG
- PAPP-A
Purpose:
- Detects risk of Down Syndrome, Trisomy 18, and Trisomy 13 early
- Gives the most accurate first-trimester result when combined with NT Scan
Importance:
- Helps plan further diagnostic tests (if needed)
- Provides maximum reassurance early in pregnancy
2. Triple Marker Test (Second Trimester Screening)
When done: 15–20 weeks
Markers tested:
- AFP (Alpha-Feto Protein)
- hCG (Human Chorionic Gonadotropin)
- Estriol (uE3)
Purpose:
- Screens for Down Syndrome & Trisomy 18
- Helps detect Neural Tube Defects (NTDs)
Importance:
- Used when Double Marker is missed or further confirmation is required
3. Quadruple Marker Test (Most Reliable Second Trimester Test)
When done: 15–22 weeks
Markers tested:
- AFP
- hCG
- Estriol (uE3)
- Inhibin-A (additional marker)
Why Quadruple Marker is better than Triple Marker:
- Higher accuracy
- Better risk detection for Down Syndrome
- More reliable for predicting complications like preeclampsia or poor placental function
Importance:
- Recommended for all high-risk pregnancies
- Best second-trimester screening option
Difference Between Double, Triple, and Quadruple Marker Tests
| Test Name | Weeks | No. of Markers | Accuracy | Best Use |
|---|---|---|---|---|
| Double Marker | 10–14 weeks | 2 | ⭐⭐⭐⭐⭐ | Early detection + NT Scan |
| Triple Marker | 15–20 weeks | 3 | ⭐⭐⭐ | If first trimester was missed |
| Quadruple Marker | 15–22 weeks | 4 | ⭐⭐⭐⭐⭐ | Most accurate in 2nd trimester |
Why NT Scan + Double Marker Test Is Recommended Together?
When combined, they provide:
✔ Highest detection rate for chromosomal abnormalities
✔ Early risk assessment
✔ Helps avoid late pregnancy surprises
✔ Safe and non-invasive
This combination is considered the gold standard for early screening.
Marker Test & NT Scan at Shree Diagnostics, Howrah
At Shree Diagnostics, we provide:
- ✔ High-resolution NT Scan by expert radiologists
- ✔ Advanced lab for marker tests
- ✔ Daily appointments
- ✔ Fast, accurate reporting
- ✔ Counseling to help you understand results
📍 Rabindra Nagar Complex, 88 College Road, Shalimar Gate No-3, Howrah – 711103
📍 58/3 Laxmi Narayan Tala Road, Howrah-711103
📞 8910830805 / 8100606500
🌐 www.shreediagnostics.in
