Management of Shoulder Dystocia
First-Line Intervention
The McRoberts maneuver combined with suprapubic pressure is the most appropriate first-line management for shoulder dystocia. 1, 2
This recommendation is based on consistent guideline consensus from the American College of Obstetricians and Gynecologists, which designates this combination as the initial intervention due to its simplicity, effectiveness, and low morbidity profile. 1, 2
Step-by-Step Algorithm
Immediate Actions (First-Line)
Position the mother in McRoberts position: Hyperflex both legs tightly to her abdomen while the patient is supine, which rotates the symphysis pubis cephalad and flattens the sacral promontory. 1, 3
Apply suprapubic pressure simultaneously: Use the palm of your hand (not just 1-2 fingers, as this is less effective and may increase fetal injury risk) to apply pressure above the pubic symphysis to dislodge the anterior shoulder from behind the pubic bone. 1
Success rate: This combination resolves 88.2% of shoulder dystocia cases when used as the primary maneuver after spontaneous vaginal delivery. 4
Critical Don'ts
- Do not pull excessively on the fetal head - this increases risk of brachial plexus injury. 5
- Do not perform fundal pressure - this worsens the impaction. 5
- Do not attempt delivery during a contraction - contractions exacerbate difficulty with head elevation and should be avoided. 3
Secondary Maneuvers (If McRoberts Fails)
If the McRoberts maneuver with suprapubic pressure is unsuccessful, proceed immediately to second-line maneuvers. The choice depends on the position of the posterior shoulder: 5
If posterior shoulder is engaged: Perform Wood's screw maneuver (internal rotation of the fetal shoulders). 5
If posterior shoulder is not engaged: Deliver the posterior arm by sweeping it across the fetal chest and out of the vagina. 5
Alternative: Manual vaginal disimpaction (vaginal push method) involves introducing a hand into the vagina to move the fetal head upward, though care must be taken to avoid further deflexion which could worsen impaction. 1
Important Clinical Context
Success Rates Vary by Delivery Type
After spontaneous vaginal delivery: McRoberts with suprapubic pressure succeeds in 47.7% of cases. 6
After instrumental delivery: Success rate drops dramatically to only 15.0%, with an 85% failure rate requiring additional maneuvers. 6
Implication: If shoulder dystocia occurs after forceps or vacuum delivery, be prepared to rapidly proceed to second-line maneuvers, as McRoberts alone will likely fail. 6
Episiotomy Considerations
- Routine episiotomy is not recommended solely for shoulder dystocia management, as it does not reduce the risk of anal sphincter injury and does not address the bony impaction problem. 1, 5
Post-Resolution Management
Administer oxytocin: Give 5-10 IU via slow IV or intramuscular injection to reduce postpartum hemorrhage risk after successful resolution. 1
Consider tranexamic acid: If postpartum hemorrhage occurs, administer 1 g IV within 1-3 hours of bleeding onset. 1
Training Imperative
All delivery room personnel should undergo simulation-based training in shoulder dystocia management, as this is strongly recommended to improve recognition, proper maneuver execution, and team communication during this obstetric emergency. 1, 2
Operators performing instrumental deliveries must be proficient in all maneuvers, not just McRoberts, given the 4.88-fold increased risk of McRoberts failure in this context. 6