Fetal Heart
When to Scan:
Pregnant patients (1st, 2nd or 3rd trimester):
- Vaginal bleed
- Abdominal pain
- Trauma
- Decreased fetal movement
- Inability to find fetal heart by doppler
Transabdominal Approach:
- Best with full bladder if 1st trimester
- Don't forget to change exam setting to OB
Transvaginal Approach:
- Used in 1st trimester if fetal heart not seen by transabdominal approach
- Best with empty bladder
Where to put the probe:
Start with same steps as Fetal Presentation:
• Begin in transverse above the pubic symphysis to locate the head
• Rotate to longitudinal then move cephalad to find the spine
When to Scan:
Pregnant patients (1st, 2nd or 3rd trimester):
- Vaginal bleed
- Abdominal pain
- Trauma
- Decreased fetal movement
- Inability to find fetal heart by doppler
Transabdominal Approach:
- Best with full bladder if 1st trimester
- Don't forget to change exam setting to OB
Transvaginal Approach:
- Used in 1st trimester if fetal heart not seen by transabdominal approach
- Best with empty bladder
Start with same steps as Fetal Presentation:
• Begin in transverse above the pubic symphysis to locate the head
• Rotate to longitudinal then move cephalad to find the spine
Findings
• Fetal heart will be in the fetal thorax adjacent to the spine
• Slide probe medial lateral or tilt to improve image
• Look for cardiac motion
Fetal Heart Rate Calculation
Transvaginal view:
• Select M-mode
• Place the M-mode cursor through the fetal heart capturing cardiac movement
• Select HR or FHR from calculations menu and place calipers at the start and end of one cycle of cardiac motion