Tricuspid Valve Regurgitation during NS screening

Role of Tricuspid Valve Regurgitation

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TR assessment is performed during the 11–13 weeks + 6 days scan, especially in cases with increased NT or other risk indicators.

Technique

1. Obtain an apical four-chamber view of the fetal heart using color Doppler.

Normal fetal four-chamber heart view

Four-Chamber View Evaluation

• Proper visualization of both atria and ventricles.
• Symmetrical size of the left and right chambers.
• Normal insertion of atrioventricular valves (TV and MV).
• Clearly defined interventricular septum (IVS), indicating no obvious septal defect.
• Spine (Sp) visible, ensuring proper orientation.
• Correct situs (left/right alignment), confirmed by L and R markers.

Section structure
1. IVS - Interventricular Septum
2. LV - Left Ventricle
3. RV - Right Ventricle
4. LA - Left Atrium
5. RA - Right Atrium
6. MV - Mitral Valve
7. TV - Tricuspid Valve
8. Ao - Aorta
9. PV - Pulmonary Vein (or Pulmonary Valve, depending on context)
10. Sp - Spine
11. L / R - Left / Right side markers of the fetus

2. Ensure the fetus is still and the heart rate is between 120–160 bpm.

3. Use a small Doppler gate over the tricuspid valve.

4. TR is identified as a reverse flow jet into the right atrium during systole

Interpretation

Normal (No TR): No significant reverse jet seen during systole (No regurgitation or brief regurgitation < 60 cm/s)
Abnormal (TR Present): Reverse jet lasting ≥ half of systole with velocity ≥ 60 cm/s(Regurgitant jet > 60 cm/s, duration > 50% of systole)
TR Indicates: TR is abnormal in ~50% of trisomy 21 cases or major cardiac anomalies
Note: TR alone is not diagnostic. It is a supplementary marker to be interpreted with other first-trimester screening results.