Amniotic Fluid
Rapid Summary
When to Scan:
Pregnant patients (2nd or 3rd trimester – after 24 weeks):
- Vaginal bleed
- Trauma
- Decreased fetal movement
- Non reassuring NST
- Post dates evaluation
Transabdominal Approach:
- Don't forget to change exam setting to OB
5 Minute Video
Where to put the probe:
• Set depth to maximum
• Divide uterus into 4 quadrants
• Start superior to umbilicus in longitudinal
• Slide laterally on abdomen to visualize entire quadrant
• Move caudad in search and rescue grid fashion looking for deepest vertical fluid pocket
• Repeat scan in remaining uterine quadrants
When to Scan:
Pregnant patients (2nd or 3rd trimester – after 24 weeks):
- Vaginal bleed
- Trauma
- Decreased fetal movement
- Non reassuring NST
- Post dates evaluation
Transabdominal Approach:
- Don't forget to change exam setting to OB
- Set depth to maximum
- Divide uterus into 4 quadrants
- Start superior to umbilicus in longitudinal
- Slide laterally on abdomen to visualize entire quadrant
- Move caudad in search and rescue grid fashion looking for deepest vertical fluid pocket
- Repeat scan in remaining uterine quadrants
Findings
• Freeze image at deepest vertical pocket
• Measure vertically with calipers
• Choose deepest pocket of the four quadrants
• >3cm normal
Note: If doing Amniotic Fluid Index – add deepest pockets in all four quadrants. >5 is normal.