What is the most appropriate maneuver to reduce the risk of shoulder dystocia before it occurs?

McRoberts Maneuver is the Most Appropriate Preventive Positioning

None of the listed options (Rubin, suprapubic pressure, Gaskin, or Zavanelli) are preventive maneuvers—they are all treatment interventions used after shoulder dystocia has already occurred. However, if the question intends to ask which maneuver should be used first when shoulder dystocia occurs, the answer is McRoberts maneuver combined with suprapubic pressure.

Understanding the Distinction: Prevention vs. Treatment

True Prevention Strategies (Before Shoulder Dystocia Occurs)

• Prophylactic cesarean delivery should be considered for suspected fetal macrosomia with estimated fetal weights >5,000g in women without diabetes and >4,500g in women with diabetes 1, 2
• Labor induction is NOT recommended for suspected macrosomia, as it doubles the cesarean delivery risk without reducing shoulder dystocia incidence 1, 2
• Recognition of warning signs during labor includes prolonged deceleration phase (8-10cm dilation) and arrest of descent in the second stage, which should prompt consideration of cesarean delivery rather than continued vaginal delivery attempts 3

First-Line Treatment When Shoulder Dystocia Occurs

The McRoberts maneuver combined with suprapubic pressure is the recommended first-line intervention when shoulder dystocia is diagnosed 2, 3, 4, 5:

• McRoberts maneuver involves hyperflexion of the mother's legs tightly to her abdomen, which straightens the sacrum and increases the pelvic outlet diameter 2, 6
• Suprapubic pressure should be applied simultaneously to help dislodge the anterior shoulder from behind the pubic symphysis 2, 4
• This combination is simple to perform, effective, and associated with the lowest neonatal morbidity compared to other maneuvers 6, 5

Why the Other Options Are NOT First-Line

Rubin Maneuver (Option A)

• This is a second-line internal rotational maneuver performed inside the vagina to rotate the fetal shoulders 7, 5
• Should only be attempted after McRoberts maneuver fails 5

Suprapubic Pressure (Option B)

• While this IS part of first-line management, it is used in combination with McRoberts, not alone 2, 4
• Critical error to avoid: Fundal pressure (pushing on top of the uterus) is contraindicated and can worsen impaction 5

Gaskin Maneuver/All-Fours (Option C)

• This involves positioning the patient on hands and knees 8
• Considered a second-line maneuver when McRoberts fails, though it shows good efficacy (83% success rate in one series) 8
• Less commonly used as first-line due to practical difficulties in repositioning during an emergency 5

Zavanelli Maneuver (Option D)

• This is a last-resort maneuver involving cephalic replacement (pushing the fetal head back into the vagina) followed by emergency cesarean delivery 4
• Only considered when all other maneuvers have failed 4

Critical Management Principles

Avoid excessive traction on the fetal head, as this is significantly correlated with brachial plexus palsy 6, 5:

• Strong downward traction has the highest association with neonatal trauma 6
• Focus on finesse rather than force when performing maneuvers 7

Time management is essential but should not lead to panic 4:

• Document the head-to-body delivery interval 4
• Most cases resolve with McRoberts maneuver within 2-3 minutes 8

Team preparation and simulation training significantly improve outcomes 2, 3, 4:

• Multiprofessional training using high-fidelity simulation is recommended 3
• All delivery personnel should know at least two maneuvers beyond McRoberts 5