Shoulder Dystocia Risks Shoulder Dystocia is an obstetric complication that turns a routine vaginal delivery into a medical emergency within moments. This occurs when the baby’s head delivers successfully, but one or both shoulders become trapped behind the mother’s pelvic bone, preventing completion of the delivery.
Although it is relatively rare (occurring in 0.3–3% of vaginal deliveries),Obstetric Emergency. American family physician, 102(2), 84–90.” style=”position:relative;color:#309b65;cursor:help;border-bottom:1px dotted #309b65;font-weight:bold”>[1] shoulder dystocia is an obstetrical emergency that requires an immediate diagnosis and expert intervention. Its variable presentation and potentially grave consequences can make it one of the most challenging obstetrical dilemmas. Nonetheless, obstetricians are familiar with the strategies for prompt identification and management, and the overwhelming majority of cases are resolved without harm.
Mechanism & Definition: Shoulder Dystocia Risks
Shoulder dystocia is defined as impaction of the fetal anterior shoulder against the maternal pubic bone (usually after the fetal head delivers). Less common is impaction of the posterior shoulder against the sacral promontory.
This mechanical impaction creates an obstetric emergency because any delay in delivery can compromise the newborn’s oxygen supply and increase the risk of traumatic injury during extraction attempts.
Clinical Signs (‘Symptoms’) of Shoulder Dystocia
Shoulder dystocia is a clinical diagnosis. It can be risk-assessed beforehand, but healthcare providers can only diagnose it on direct observation during delivery. The condition becomes recognisable when routine pushing efforts by the mother and gentle downward traction fail to deliver the baby’s body after the head has emerged.
Some of the sure signs of shoulder dystocia are:
- Extended head-to-body delivery interval > 60 seconds
- The “turtle sign”: Retraction of the fetal head against the perineum and crowning as it impacts the shoulder (dystocia)[2]
- Difficulty in rotating the head externally, or delivering the face and chin
- Anterior shoulder entrapment beneath the pubic symphysis despite standard maneuvers
There are no prenatal screening tests for shoulder dystocia. Moreover, even if a comprehensive risk assessment is performed, it will be impossible to identify the individual fetus experiencing a shoulder dystocia. As such, all patients during the second stage of labor should be closely monitored.
Misdiagnosis of Shoulder Dystocia
Diagnosing shoulder dystocia well involves differentiating it from other delivery complications. Misdiagnosis can occur in one of two ways:
- Over-diagnosis: Qualifying a challenging but manageable birth as shoulder dystocia when the usual obstetric maneuvers would be adequate. This can lead to over-intervention and increase anxiety for the mother.
- Underdiagnosis: When shoulder dystocia requires the appropriate maneuvers and is managed as if it were a normal delivery. This can result in increased risk for morbidities and possible lethality.
To avoid misdiagnosis, it is essential that the range of normal delivery be understood, and the clinical findings above recognized, in addition to maintaining good documentation of the head-to-body delivery time in the medical record.
What Causes Shoulder Dystocia?
Shoulder dystocia can occur in any pregnancy, even if the clinician isn’t able to see any obvious risk factors. However, some situations can make it more likely:
a. Fetal Factors:
- Macrosomia (birth weight >4.0–4.5 kg)
- Increased shoulder-to-head ratio
- Post-term pregnancy
b. Maternal Factors:
- Pre-gestational or gestational diabetes
- Elevated body mass index
- Excessive gestational weight gain
- Previous history of shoulder dystocia
c. Labor-Related Factors:
- Prolonged second stage of labor
- Instrumental delivery (forceps or vacuum assistance)
- Rapid labor progression
- Maternal positioning during delivery
Risk stratification is limited in predicting shoulder dystocia. Most women identified with multiple risk factors deliver without complications, while others with no apparent risk factors experience unexpected shoulder impaction. This unpredictability is why obstetric teams must maintain constant readiness rather than relying on risk-based prevention strategies.
Emergency Management Protocols for Shoulder Dystocia
There are established protocols to make sure shoulder dystocia can be promptly recognised and to relieve the obstruction while minimizing maternal and neonatal morbidity.
Initial Response:
- Call for help: summon additional obstetric, anesthesia, and neonatal teams immediately.
- Stop maternal pushing to prevent further impaction
- Avoid excessive traction on the fetal head or neck (can increase the risk of brachial plexus injury)
- Document timing precisely for accurate recording of the head-to-body delivery interval
First-Line Maneuvers:
McRoberts Maneuver
This primary intervention involves hyperflexing and abducting the mother’s hips toward her abdomen. The maneuver flattens lumbar lordosis and rotates the pelvis, effectively increasing the anteroposterior pelvic diameter. Studies show McRoberts’ positioning alone resolves approximately 40% of shoulder dystocia cases.[3]
McRoberts Maneuver. An illustration of how to perform the McRoberts maneuver (arrow 1) and apply suprapubic pressure (arrow 2). (Image Courtesy: Illustration bygeraldbaeck. via Wikipedia commons, CC0.
Suprapubic Pressure
Applied directly above the pubic bone with oblique posterior pressure, this technique aims to rotate the fetal shoulders into a more favorable oblique position, often freeing the anterior shoulder.
Secondary Maneuvers (if Unresolved):
When first-line measures fail, clinicians proceed systematically through additional maneuvers:
Rotational Maneuvers
- Rubin maneuvers (I and II) involve manipulation by hand to rotate the anterior shoulder into a more favorable position.
- Woods screw maneuver applies rotational pressure to the posterior shoulder to “unscrew” the fetus from impaction.
Illustration of Rubin I maneuver: Applying suprapubic pressure to the anterior fetal shoulder to shift the shoulder into a wider pelvic diameter. (Image Courtesy: Illustration by Felipe Lage Starling. Alves, Á. L. L., Nozaki, A. M., Polido, C. B. A., & Knobel, R. (2022). Management of shoulder dystocia. Revista brasileira de ginecologia e obstetricia : revista da Federacao Brasileira das Sociedades de Ginecologia e Obstetricia, 44(7), 723–736. Available fromRBGO. Licenced under CC by 4.0)
Delivery of Posterior Arm
This technique involves flexing and sweeping the posterior arm across the chest and delivering it, which significantly reduces the bisacromial diameter and allows completion of delivery.[4]
Last-Resort Options
- Gaskin maneuver, positioning the mother on hands and knees to widen the pelvic outlet (more common in out-of-hospital settings)
- Intentional clavicular fracture reduces shoulder width in refractory cases
- Zavanelli maneuver (cephalic replacement followed by cesarean delivery) represents the final option when all else fails
A flowchart showing the emergency management strategy flow for shoulder dystocia.
Shoulder Dystocia Long-Term Effects
Shoulder dystocia carries risks for both the newborn and the mother. Many cases are resolved without damage, but potential complications are why rapid recognition and skilled management are so stressed upon amongst obstetric teams.
Neonatal Complications:
- Brachial plexus injury: The most common complication, involving damage to network of nerves that control arm and hand function. Most cases are due to temporary neuropraxia with complete recovery over 6-12 months.[5] More severe damage can lead to persistent weakness or paralysis, especially Erb’s palsy that affects the upper arm.[6]
- Skeletal fractures: Clavicular and humeral fractures are relatively uncommon but sometimes are difficult to avoid during difficult delivery, or can be created by the clinician to facilitate delivery. Such fractures heal completely in almost all cases with full functional recovery.
- Hypoxic complications: Head to body delivery interval should be as brief as possible to prevent fetal hypoxemia, which can lead to acidosis and even hypoxic-ischemic encephalopathy in severe cases.
Position of the arm in brachial plexus palsy as a result of shoulder dystocia. (Image Courtesy: Monod, Cécile & Hoesli, Irene & Akra, Samira & Gisin, Martina & Butenschoen, Annkathrin & Katsaouni, Stavroula & Fiechter, Lara & Redling, Katharina. (2025). Shoulder Dystocia. 10.1007/978-3-031-81931-5_9. Available fromSpringer Nature.Licenced under CC by 4.0)
Maternal Complications:
Mothers face several potential complications:
- Postpartum hemorrhage from uterine atony or soft tissue trauma
- Severe perineal lacerations (third or fourth degree tears)
- Pelvic injury, including symphyseal separation (rare but possible with forceful maneuvers.)
- Psychological trauma from the emergency nature of the event
Treatment & Recovery
The management of shoulder dystocia is at the time of delivery, through the maneuvers described earlier. Once delivery is complete, attention shifts quickly to comprehensive assessment of both baby and mother:
Immediate Postpartum Care:
Following successful delivery, care focuses on comprehensive assessment and support:
Neonatal Evaluation
- Respiratory status assessment and resuscitation if needed
- Neurological examination for brachial plexus function
- Skeletal evaluation for fractures
- Ongoing monitoring for signs of hypoxic injury
Maternal Assessment
- Evaluation for hemorrhage and soft tissue trauma
- Pain management and supportive care
- Psychological support and counseling
Recovery Patterns:
Overall, the majority of shoulder dystocias have good long-term outcomes:
- Brachial plexus injuries resolve completely in 80-90% of cases at 6-12 months.
- Bone fractures heal without functional impairment.
- Infants with complications from nerve injury or hypoxia need long-term follow-up with neurology, orthopedics, or developmental medicine.
- Maternal recovery is usually assured with standard postpartum care. A few women may have pelvic floor concerns, pain, or long-term consequences of a severe perineal laceration.
Psychological Impact:
An often-overlooked element is the emotional impact of shoulder dystocia. Parents may experience distress or anxiety after a complicated delivery, especially if the baby required resuscitation or sustained an injury. Support from healthcare teams, counseling, and clear follow-up can help families process the experience.
Prevention Strategies & Limitations
There is no guaranteed way to prevent shoulder dystocia. Most cases occur unpredictably, even in pregnancies without known risk factors. However, evidence-based strategies can reduce likelihood in high-risk scenarios.
Evidence-Based Prevention Recommendations:
Professional guidelines propose specific measures for avoiding shoulder dystocia and its complications:
Labor Induction
- Recommended for impending macrosomia when the cervix is favorable at 39 weeks or greater gestational age.[7]
Elective Cesarean delivery before Labor
- Estimated fetal weight (EFW) >4,500g when associated with maternal diabetes
- EFW > 5,000g in women without diabetes
- History of shoulder dystocia associated with severe neonatal or maternal complications[8]
Cesarean during Labor
- Fetal macrosomia combined with failure to progress in the second stage when fetal head position remains high.
General Risk Reduction Approaches:
- Managing maternal diabetes: Optimal blood glucose control during pregnancy reduces excessive fetal growth
- Weight management: Following evidence-based guidelines for gestational weight gain minimizes macrosomia risk
- Labor preparedness: Ensuring trained personnel and established protocols are in place represents the most effective safeguard
Despite risk factor identification, shoulder dystocia prediction remains unreliable. The condition’s low overall incidence means preventive measures like routine elective cesarean would subject many women to surgical risks without benefit.
Importantly, shoulder dystocia is not caused by anything parents did or failed to do. It represents a complication of childbirth that can occur despite optimal care, which is why obstetric teams focus on readiness and rapid response rather than prevention strategies alone.
Conclusion
Shoulder dystocia represents one of obstetrics’ most challenging emergency scenarios: unpredictable, yet demanding immediate, skilled intervention. While the condition cannot be reliably prevented, systematic preparation, skilled management, and compassionate follow-up care invariably results in the best possible outcome for mother and baby.
Most cases of shoulder dystocia have a successful resolution, and all parties make a full recovery, with any complications being transient and amenable to proper care. This positive outlook, combined with continuing advances in obstetric emergency management, provides reassurance that shoulder dystocia, while serious, need not result in poor long-term outcomes when handled with expertise and care.
Success in managing shoulder dystocia ultimately depends not on prediction or prevention, but on recognition, rapid response, and systematic application of proven techniques by well-prepared healthcare teams. This approach transforms a potentially catastrophic event into a manageable emergency with favorable outcomes for families and healthcare providers alike.
References
[1] Hill, D. A., Lense, J., & Roepcke, F. (2020). Shoulder Dystocia: Managing an Obstetric Emergency. American family physician, 102(2), 84–90.
[2] Moore C, Bell D, Iqbal S, Turtle sign (fetal shoulder dystocia). Reference article, Radiopaedia.org (Accessed on 28 Aug 2025) https://doi.org/10.53347/rID-71627
[3] Gesner T, Toncar A, Jenkins SM, et al. McRoberts Maneuver. [Updated 2024 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537280/
[4] Alves, Alvaro & Nozaki, Alexandre & Andreucci, Carla Betina & Knobel, Roxana. (2022). Management of shoulder dystocia. Revista Brasileira de Ginecologia e Obstetricia / RBGO – Gynecology and Obstetrics. 44. 723-736. 10.1055/s-0042-1755446.
[5] Perkins, R., & Nadeem, S. (1994).The natural history of obstetrical brachial plexus palsy.Journal of Pediatric Orthopaedics, 14(4), 394–397.
[6] Hill, M. G., & Cohen, W. R. (2016). Shoulder Dystocia: Prediction and Management. Women’s Health, 12(2), 251. https://doi.org/10.2217/whe.15.103
[7] Sentilhes, L., Sénat, M.-V., Boulogne, A.-I., Deneux-Tharaux, C., Fuchs, F., Legendre, G., Le Ray, C., Lopez, E., Schmitz, T., & Lejeune-Saada, V. (2016). Shoulder dystocia: Guidelines for clinical practice from the French College of Gynecologists and Obstetricians (CNGOF). European Journal of Obstetrics and Gynecology and Reproductive Biology, 203, 156–161. https://doi.org/10.1016/j.ejogrb.2016.05.047
[8] Hill, M. G., & Cohen, W. R. (2016). Shoulder Dystocia: Prediction and Management. Women’s Health, 12(2), 251. https://doi.org/10.2217/whe.15.103