Vacuum-Assisted Delivery and Risk of Subgaleal Hemorrhage

Performing more than three vacuum pulls during vacuum-assisted delivery significantly increases the risk of subgaleal hemorrhage. 1

Evidence on Vacuum Pull Limits

Compliance with clinical guidelines limiting vacuum pulls to three or fewer is associated with a significant reduction in the incidence of subgaleal hemorrhage (0% vs 11%, P = 0.0002) 1
The main deviation from clinical guideline compliance in vacuum-assisted deliveries is pulls exceeding three, which directly correlates with increased risk of adverse outcomes 1
Exceeding three pulls is also associated with increased risk of major birth trauma (3% vs 22%, P = 0.0001) and poorer neonatal outcomes including lower Apgar scores 1

Subgaleal hemorrhages are potentially lethal intracranial bleedings that occur most commonly after difficult vacuum extraction 2
Risk factors that compound the danger of multiple vacuum pulls include:
- Primiparous women 2
- Severe dystocia 2
- Occiput lateral or posterior head presentations 2
- Forceful or prolonged use of vacuum suction 2
- Unfavorable cup applications (deflexing and paramedian) 3

Vacuum extraction itself predisposes an infant toward subgaleal bleeding, with risk increasing with each additional pull 2
Subgaleal hemorrhage can cause hypovolemic shock, which may be fatal if not promptly recognized and treated 2
The bleeding occurs into the potential space between the galea aponeurotica and the periosteum of the skull 4
Even with modern silicone elastomer vacuum cups (which reduced the frequency compared to older metal cups), the risk remains significant 4

Limiting vacuum extraction to three pulls is a critical safety measure to prevent subgaleal hemorrhage 1
Vacuum duration should not exceed 15 minutes, and more than two cup detachments should be avoided 5
When compared with extractions adhering to safety recommendations, the odds for intracranial hemorrhage were nine-fold (OR 8.91) among infants exposed to protracted extraction 5
After adjustments for potential confounders, the odds ratio remained high at 8.04 (95% CI 4.49-14.38) 5

If vacuum-assisted delivery cannot be accomplished within three pulls, consider alternative delivery methods 1
Continuous electronic fetal heart rate monitoring is recommended during operative vaginal delivery 6
The use of a single forceps blade or ventouse as a lever to disimpact the fetal head is considered dangerous and should be avoided 7
The use of vacuum at cesarean delivery has the potential to cause significant fetal injury, including intracranial and subgaleal hemorrhage 7

Close monitoring is essential for infants delivered by vacuum extraction, especially when multiple pulls were required 4
Monitor vital signs, hematocrit, blood gases, head circumference, and signs of tissue hypoperfusion 4
Be alert for ballotable cranial fluid collections and signs of volume loss, which may indicate subgaleal bleeding 2
Treatment of symptomatic subgaleal hematoma requires prompt restoration of blood volume and control of bleeding 2