What is the recommended number of pulls allowed with a labour vacuum (vacuum extractor)?

Maximum Number of Pulls Allowed with a Labour Vacuum

The maximum number of pulls allowed with a labour vacuum extractor should be limited to three pulls, with no more than two pop-offs (detachments) of the cup, to minimize the risk of fetal injury including intracranial and subgaleal hemorrhage.

Guidelines for Vacuum Extraction Use

Vacuum extraction is a technique for operative vaginal delivery that requires proper training and understanding of risks. The American College of Obstetricians and Gynecologists provides clear guidance on its use 1:

• Only properly trained clinicians should perform vacuum extractions
• A single appropriate vacuum device should be chosen based on the clinical situation
• Sequential use of multiple vacuum types is strongly contraindicated due to significant risk of fetal injury

Key Safety Parameters

When performing vacuum extraction, the following safety parameters should be observed:

• Maximum number of pulls: 3
• Maximum number of cup detachments: 2
• Maximum duration of vacuum application: 15-30 minutes (depending on institutional protocols)

Signs to Discontinue Vacuum Extraction

The procedure should be immediately discontinued if:

• No descent with proper traction
• Cup detaches more than twice
• Three pulls have been completed without delivery
• Total vacuum application time exceeds 30 minutes
• Signs of fetal scalp trauma develop

Contraindications for Vacuum Use

Vacuum extraction is absolutely contraindicated in several situations:

• Before complete cervical dilation 1
• During cesarean delivery (high risk of fetal injury) 1, 2
• As a lever to disimpact the fetal head during cesarean delivery 2
• When used in combination with forceps (sequential instrumentation)
• Gestational age less than 34 weeks (increased risk of intracranial hemorrhage)
• Fetal bleeding disorders or demineralizing bone diseases

Risks and Complications

Vacuum extraction carries specific risks that must be considered:

• Maternal risks: Increased risk of postpartum hemorrhage and higher degrees of perineal tears 1
• Neonatal risks: Subgaleal hemorrhage, cephalohematoma, caput succedaneum, and intracranial hemorrhage 1

The risk of subgaleal hemorrhage is significantly higher with vacuum-assisted delivery compared to spontaneous vaginal delivery. This risk increases with:

• Multiple cup detachments
• Prolonged vacuum application
• Excessive number of pulls

Proper Technique

To minimize complications:

1. Ensure proper cup placement (over the flexion point)
2. Apply vacuum gradually in increments
3. Pull in coordination with maternal contractions
4. Pull perpendicular to the cup in the direction of the pelvic curve
5. Avoid rocking or twisting movements
6. Count and document the number of pulls
7. Monitor for cup detachments

Monitoring After Vacuum Delivery

All neonates delivered by vacuum extraction should be closely monitored for:

• Signs of subgaleal hemorrhage (increasing head circumference, fluctuant scalp)
• Neurological status
• Vital signs
• Hemoglobin levels if concerning signs present

Healthcare providers should be prepared to recognize and manage subgaleal hemorrhage promptly if it occurs 1.

While vacuum extraction can be an effective technique for operative vaginal delivery when properly applied 3, 4, strict adherence to safety guidelines including the three-pull maximum rule is essential to minimize the risk of maternal and neonatal complications.