Recommended Fetal Station for Vacuum Extraction
Vacuum extraction should only be applied when the fetal head is at or below station +2 (at least 2 cm below the ischial spines), as higher stations significantly increase the risk of failed vacuum delivery, cesarean section, and fetal injury. 1, 2
Vacuum Extraction Safety Parameters
- Vacuum extraction should not be attempted when the fetal head is at station 0 or above (at the level of ischial spines or higher), as this is associated with increased risk of infant mortality, cerebral damage, and brachial plexus injury 2
- Ultrasound measurements can help determine appropriate station, with a head-perineum distance ≤35 mm being associated with higher success rates and fewer complications 3
- The use of vacuum at cesarean delivery is contraindicated due to potential for significant fetal injury, including intracranial and subgaleal hemorrhage 1
Risk Factors for Failed Vacuum Extraction
- Higher fetal stations (above +2) are associated with:
Proper Technique Considerations
- Continuous electronic fetal heart rate monitoring is recommended during vacuum-assisted delivery 1
- Vacuum extraction should be limited in duration, with studies showing increased complications when extraction exceeds 14 minutes 2
- Suspected cephalopelvic disproportion is a contraindication for vacuum-assisted vaginal delivery 4
- Proper cup placement with flexing applications (over the flexion point) is critical for successful vacuum extraction 5
Common Pitfalls to Avoid
- Using vacuum extraction as a lever to disimpact the fetal head is dangerous and should be avoided 1, 6
- Attempting vacuum extraction at high stations (above +2) should be replaced by cesarean section 2
- Prolonged vacuum attempts (>15 minutes) should be abandoned as they are associated with increased neonatal morbidity 7
- Failure to recognize when to abandon vacuum attempts can lead to increased maternal and fetal trauma 7
Vacuum extraction can be a safe and effective procedure when performed by skilled providers with appropriate patient selection. The most recent evidence strongly supports limiting vacuum extraction to cases where the fetal head is at or below station +2 to minimize risks of maternal and fetal complications 2, 3.