## Vacuum Extraction: Traction Force Guidelines ### Safe Traction Parameters **Key Point:** Vacuum extraction requires **controlled, progressive traction** to minimize fetal scalp trauma. The recommended maximum traction force is **5–8 kg per contraction** (approximately 11–18 lbs), applied in coordination with uterine contractions and maternal pushing effort. ### Mechanism of Injury Prevention Excessive traction force (>8–10 kg) increases the risk of: - Cephalohematoma - Subgaleal (subaponeurotic) hemorrhage — potentially life-threatening - Scalp lacerations and bruising - Intracranial hemorrhage - Chignon (caput succedaneum from vacuum cup) ### Vacuum Extraction Safety Rules | Parameter | Guideline | | --- | --- | | **Traction force** | 5–8 kg per contraction (maximum) | | **Number of pulls** | ≤3 pulls per contraction | | **Cup detachments (pop-offs)** | ≤2–3 detachments; if ≥3, abandon and proceed to cesarean | | **Time limit** | ≤20 minutes total application time | | **Maternal effort** | Requires adequate contractions and maternal pushing | **High-Yield:** According to standard obstetric references (Williams Obstetrics, 26th edition; Operative Obstetrics by Gilstrap & Cunningham), the safe traction force during vacuum extraction is **5–8 kg** per contraction. Forces exceeding this threshold significantly increase the risk of scalp and intracranial injury without improving delivery success. **Clinical Pearl:** The traction should always be applied in the axis of the birth canal (Pajot's maneuver principle), coordinated with contractions and maternal expulsive effort. Modern soft silicone cups require even more careful force control than rigid metal cups. Excessive force does not improve success rates; it only increases fetal morbidity. **Reference:** Williams Obstetrics, 26th ed., Chapter on Operative Vaginal Delivery; Munro Kerr's Operative Obstetrics.
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.