Shoulder dystocia (SD) is one of the most unpredictable and stressful obstetric emergencies, defined as the failure of the shoulders to deliver spontaneously after the head has emerged. It is a time-critical event; delays in delivery can lead to fetal asphyxia, hypoxic-ischemic encephalopathy, and severe brachial plexus injury (BPI). Successful management relies on immediate recognition, rapid mobilization of the delivery team, and the systematic, sequential application of specific maneuvers designed to disengage the impacted anterior shoulder from behind the maternal symphysis pubis.
Recognition, Preparation, and Time Management
The immediate priority is to recognize the situation and coordinate the response.
Step 1: Recognition and Activation
The hallmark sign of shoulder dystocia is the “turtle sign,” where the fetal head retracts tightly against the maternal perineum following maximal effort, or the failure of the fetal shoulder to follow after the head is delivered with routine traction.
- Immediate Call: Activate the shoulder dystocia protocol immediately. Call for essential assistance: an extra nurse, a pediatric/neonatal resuscitation team, anesthesia, and an additional obstetric provider (senior resident or attending physician).
- Stop Pushing and Traction: Instruct the mother to immediately stop pushing. Excess fundal pressure or forceful downward traction on the fetal head can worsen the impaction, potentially leading to increased risk of BPI or fetal trauma.
- Designate a Timekeeper: A team member must be assigned solely to announce the elapsed time from the head delivery (the moment of diagnosis) every minute.
Step 2: Initial Positioning – McRoberts Maneuver
The McRoberts maneuver is the foundational, first-line intervention due to its high success rate and minimal invasiveness.
- Execution: The mother’s thighs are sharply flexed toward her abdomen, hyperflexing the hips, often requiring two assistants, one for each leg.
- Mechanism of Action: This positioning flattens the sacrum relative to the lumbar spine, rotates the maternal pelvis superiorly, and significantly increases the functional anteroposterior diameter of the maternal outlet. This change in pelvic orientation and increased space often allows the impacted shoulder to dislodge.
- Assessment: After positioning, gentle but steady downward traction (consistent with normal delivery effort) on the fetal head should be attempted for 10–20 seconds to assess for delivery. If unsuccessful, proceed without delay.
Step 3: Supplemental Pressure – Suprapubic Pressure
Suprapubic pressure (SPP) is applied concurrently with the McRoberts maneuver if the initial attempt is unsuccessful. This differs critically from fundal pressure, which is contraindicated.
- Execution: An assistant applies firm pressure externally over the suprapubic area, aiming the force obliquely downward and toward the fetal back. This pushes the anterior shoulder from its impacted position toward the oblique diameter of the pelvis.
- Direction: The pressure should be applied either continuously or in a rocking motion (resuscitating the baby) to maximize rotational disimpaction.
- Goal: The goal of SPP is to reduce the bisacromial diameter by rotating the anterior shoulder underneath the symphysis.
Secondary and Rotational Maneuvers
If McRoberts and Suprapubic Pressure fail within 60–90 seconds of diagnosis, the provider must transition immediately to internal, rotational maneuvers. The provider must place their hand into the vagina to manipulate the fetus directly.
Step 4: Rotational Maneuvers (Rubin II and Woods Corkscrew)
These maneuvers seek to rotate the fetus to move the impacted bisacromial diameter into the widest pelvic diameter.
- Rubin II Maneuver: The provider inserts the fingers (or the entire hand) vaginally and applies pressure to the posterior aspect of the impacted anterior shoulder. The goal is to rotate the shoulders into an oblique diameter, effectively reducing the girth.
- Woods Corkscrew Maneuver: This is often performed concurrently or sequentially with the Rubin II. The provider applies pressure to the anterior (clavicular) surface of the posterior shoulder while simultaneously pushing on the posterior surface of the anterior shoulder (performing a Rubin II). The simultaneous forces act as a couple, rotating the fetal body 180 degrees into the wider oblique plane.
- Focus: The key to these maneuvers is to apply pressure to the posterior aspect of the shoulders, rotating the fetus without applying traction to the head, thereby minimizing the risk of BPI.
Step 5: Delivery of the Posterior Arm
If rotational maneuvers fail, delivering the posterior arm is often highly effective, as it significantly reduces the bisacromial diameter and usually relieves the impaction.
- Technique: The provider follows the fetal humerus down to the elbow and flexes the fetal forearm across the chest. The hand and arm are then gently swept across the fetal chest and delivered past the perineum. This maneuver requires lubrication and careful, non-forceful movement.
- Potential Complication: While highly successful, there is a risk of humerus or clavicle fracture if the arm is pulled forcefully or extended beyond its functional range. However, a fractured clavicle is usually preferable to permanent neurological damage or hypoxia.
Tertiary and Last Resort Maneuvers
If the fetus remains undelivered after several attempts (typically 3–5 minutes from diagnosis), the maneuvers of last resort must be considered. These carry higher risks but are necessary to prevent death or severe permanent neurological injury.
Step 6: The All Fours (Gaskin) Maneuver
This maneuver involves repositioning the mother onto her hands and knees (all fours). This is often difficult to execute quickly, especially if the mother has an epidural, but can be highly effective.
- Mechanism: The change in position results in a pronounced sag of the abdomen, utilizing gravity and significantly changing the pelvic angle (similar to McRoberts but often more radical). The symphysis shifts, allowing the impacted shoulder to drop free.
- Execution: The mother is quickly assisted by the team to flip to the hands-and-knees position. Once positioned, gentle, downward traction is applied to the head to effect delivery.
Step 7: Intentional Clavicle Fracture (Cleidotomy)
If the prior steps have failed and the fetus is demonstrating signs of severe distress (or death), purposeful fracture of the fetal clavicle may be performed to collapse the shoulder girdle.
- Technique: Pressure is applied digitally or with instruments to fracture the anterior clavicle laterally. This reduces the shoulder diameter instantly, often allowing for delivery. While resulting in a fracture, this is a life-saving measure.
Step 8: Zavanelli Maneuver and Symphysiotomy
These are considered the absolute last resorts, generally requiring immediate operating theatre access.
- Zavanelli Maneuver: This involves cephalic replacement (pushing the fetal head back into the vagina) followed by emergency Cesarean section. This is extremely risky for the fetus and must be performed rapidly and under anesthesia.
- Symphysiotomy: Incision of the symphysis pubis to widen the pelvic outlet. This is rarely performed in developed nations but remains an option in resource-poor settings; it carries significant risks of maternal injury, infection, and long-term disability.
Post-Delivery Care and Documentation
Once the baby is delivered, attention must immediately shift to resuscitation and documentation.
Step 9: Neonatal and Maternal Assessment
- Neonatal Care: The infant must receive immediate neonatal resuscitation and assessment for potential injuries, particularly BPI (Erb’s palsy) and fractures.
- Maternal Care: The mother must be assessed for postpartum hemorrhage (PPH) and lacerations, especially higher-grade extensions or vaginal wall tears, as aggressive manipulation can cause trauma.
Step 10: Documentation and Debriefing
Meticulous documentation is paramount in shoulder dystocia management, serving both clinical and medico-legal purposes.
- Details Required: Record the exact time of head delivery, the time of diagnosis, the total time elapsed until completion of delivery, the sequence and exact execution of every maneuver attempted (e.g., “McRoberts performed at 1 minute, suprapubic pressure applied rocking for 30 seconds, followed by Rubin II rotation,” etc.).
- Team Debrief: A formal debriefing of the team is essential to discuss what worked, what failed, and to provide emotional support, reinforcing the team’s preparedness for future events.
Conclusion
The successful management of shoulder dystocia is the purest test of a delivery team’s coordination, skill, and adherence to protocol. Effective delivery relies on the sequential, rapid application of the maneuvers, moving from the least invasive (McRoberts) to the most invasive (rotational and posterior arm delivery). Regular training, simulation drills, and immediate recognition are indispensable tools for reducing fetal morbidity associated with this obstetric emergency.
References
American College of Obstetricians and Gynecologists (ACOG). (2018). Shoulder Dystocia. Practice Bulletin No. 178. Obstetrics & Gynecology, 131(5), e119-e129.
Royal College of Obstetricians and Gynaecologists (RCOG). (2012). Shoulder Dystocia. Green-top Guideline No. 42. London: RCOG Press.
Gaskin, I. M. (2015). Ina May’s Guide to Childbirth. Bantam Books. (Reference for the Gaskin maneuver.)*
Hofmeyr, G. J., & Kulier, R. (2012). Hands-and-knees posture for facilitating childbirth. Cochrane Database of Systematic Reviews, (7).
Smith, R. B., Campbell, D., & Gooi, A. (1997). Incidence and predictive factors of shoulder dystocia in women with gestational diabetes. Australian and New Zealand Journal of Obstetrics and Gynaecology, 37(1), 37-40.
