What are the maneuvers to resolve shoulder dystocia in a patient, particularly those with risk factors such as gestational diabetes, obesity, or a history of previous shoulder dystocia?

Management of Shoulder Dystocia

First-Line Intervention

The McRoberts maneuver combined with suprapubic pressure should be performed immediately as the first-line intervention for shoulder dystocia, as this combination successfully resolves 42-58% of cases and is associated with lower rates of neonatal injury compared to more invasive maneuvers 1, 2, 3.

Initial Response Protocol

• Call for help immediately and announce "shoulder dystocia" to activate the emergency response team 4
• Position the mother in McRoberts position: hyperflexion of maternal thighs tightly against the abdomen, which increases the relative anterior-posterior diameter of the pelvis 1, 4
• Apply suprapubic pressure simultaneously: firm downward pressure just above the pubic symphysis (NOT fundal pressure) to dislodge the anterior shoulder 1, 2
• Document the time from delivery of the head to track the duration of dystocia 5, 4

This two-maneuver combination alone resolves shoulder dystocia in 58% of cases without requiring more complex interventions 2.

Second-Line Maneuvers (If McRoberts/Suprapubic Pressure Fails)

If the first-line approach fails after 30-60 seconds, proceed immediately to internal rotational maneuvers or delivery of the posterior arm, as these resolve nearly all remaining cases 2, 6.

Internal Rotational Maneuvers

• Rubin maneuver: Insert hand vaginally and push on the posterior aspect of the most accessible fetal shoulder to rotate the shoulders into the oblique diameter 4, 6
• Woods screw maneuver: Apply pressure to the anterior aspect of the posterior shoulder to rotate the fetus 180 degrees, bringing the posterior shoulder anterior 4, 2, 6

Delivery of Posterior Arm

• Insert hand along the posterior shoulder and sweep the posterior arm across the fetal chest and deliver it 4, 2, 6
• This maneuver may cause clavicular fracture but successfully resolves dystocia when rotational maneuvers fail 2

Important caveat: Research demonstrates that individual maneuvers (Rubin, Woods screw, posterior arm delivery) show no significant difference in neonatal morbidity when adjusted for duration of dystocia, which serves as a surrogate for severity 6. Therefore, use whichever maneuver you can execute most efficiently rather than rigidly following a sequence.

Third-Line Maneuvers (Rarely Needed)

If all standard maneuvers fail (occurs in <2% of cases), consider 4, 2:

• Shoulder shrug technique: Shrug the posterior shoulder and rotate the head-shoulder unit 180 degrees 7
• Intentional clavicular fracture: Apply direct pressure to fracture the clavicle and reduce shoulder diameter 4
• Zavanelli maneuver (cephalic replacement): Replace the fetal head into the vagina and proceed to emergency cesarean delivery 4

Risk Factors and Prevention Context

While you asked about patients with specific risk factors, understand that most shoulder dystocia cases occur without warning in patients without identifiable risk factors 4. However, be particularly vigilant when:

• Fetal macrosomia >4,500g is present: 9.2-24% risk in non-diabetic patients, 19.9-50% in diabetic patients 8
• Gestational diabetes is diagnosed: screening and treatment after 24 weeks reduces macrosomia and shoulder dystocia risk 9, 8
• Maternal obesity (BMI >40 kg/m²) is present: increases risk of shoulder dystocia and associated injuries 8
• Previous shoulder dystocia occurred: significantly increases recurrence risk 9, 8
• Prolonged second stage or arrest of descent with suspected macrosomia: consider cesarean delivery rather than operative vaginal delivery 1

Critical Practice Points

• Never apply fundal pressure during shoulder dystocia—this worsens impaction and increases injury risk 4
• Neonatal injury rates (brachial plexus palsy, fractures) increase with the number of maneuvers required, reflecting severity rather than maneuver choice 2, 6
• Duration of dystocia (head-to-body delivery interval) is the most important predictor of neonatal morbidity, so work efficiently through the algorithm 6
• Regular simulation training significantly improves team performance and outcomes when shoulder dystocia occurs 1, 8, 4
• Document the sequence and timing of all maneuvers performed for medicolegal purposes 5