Vacuum-Assisted Vaginal Delivery at Low Station
Vacuum-assisted vaginal delivery should not be performed at low station due to the increased risk of significant fetal injury, including intracranial and subgaleal hemorrhage. 1
Understanding Station in Vaginal Delivery
- Station refers to the position of the fetal presenting part in relation to the ischial spines of the maternal pelvis 2
- Low station generally indicates that the fetal head is below the ischial spines but has not yet reached the pelvic floor
Contraindications for Vacuum-Assisted Delivery
- The use of vacuum extraction at low station is contraindicated due to potential fetal complications 1
- Suspected cephalopelvic disproportion is an absolute contraindication for vacuum-assisted vaginal delivery 3
- Vacuum extraction should be avoided in women with maternal coagulation disorders due to increased risk of maternal hemorrhage 1
- Vacuum should be avoided in cases of maternal hepatitis C with high viral load to reduce vertical transmission risk 1
Risks Associated with Vacuum Use at Low Station
- The use of vacuum at cesarean delivery has been shown to cause significant fetal injury, including intracranial and subgaleal hemorrhage 1
- Using a vacuum extractor as a lever to disimpact the fetal head is considered dangerous and should be avoided 1, 4
- Vacuum extraction is associated with increased risk of neonatal cephalhaematoma and retinal hemorrhages compared to forceps 5
- Soft-cup vacuum extractors cause fewer neonatal scalp injuries but detach more frequently than metal-cup devices 6
Alternative Approaches for Difficult Deliveries
- For impacted fetal head during cesarean delivery, the "pull" method (including reverse breech extraction and Patwardhan method) may be safer than vaginal disimpaction techniques 7
- The Patwardhan method is a modification of reverse breech extraction that requires specialist training 7
- Continuous electronic fetal heart rate monitoring is recommended during operative vaginal delivery 1
- High-fidelity simulation and implementation of standardized care pathways represent the safest and most effective form of training for difficult deliveries 7
Important Considerations
- Proper technique is crucial as errors in performing extractions may increase the risk of fetal fractures and other injuries 4
- Complete documentation is essential when performing any assisted vaginal delivery 6
- Many obstetricians lack adequate training and confidence to perform advanced delivery techniques 7
- The lateral decubitus position for the mother can help attenuate hemodynamic impact of uterine contractions during operative delivery 3