What maneuver is used to prevent shoulder dystocia in a 41-week gestation female patient in labor with a 4.5kg fetus?

Management of Shoulder Dystocia in a 41-Week Gestation with 4.5kg Fetus

Suprapubic pressure (Option D) is the most commonly used maneuver to prevent and manage shoulder dystocia, typically employed in combination with the McRoberts maneuver as first-line interventions. 1, 2, 3

Understanding the Clinical Context

This patient presents with significant risk factors for shoulder dystocia:

• Post-term gestation (41 weeks) increases macrosomia risk 4
• Estimated fetal weight of 4.5kg places this delivery at 9.2-24% risk for shoulder dystocia 4
• Risk of brachial plexus injury is 18-21 fold higher at this birth weight 4

First-Line Maneuvers for Shoulder Dystocia Management

McRoberts maneuver combined with suprapubic pressure represents the initial approach:

• Suprapubic pressure is used in 90.2% of shoulder dystocia cases across all maternal body mass index categories 3
• McRoberts maneuver is employed in 96.0% of cases, making it the most frequently used positioning technique 3
• These two maneuvers work synergistically: McRoberts rotates the symphysis cephalad and flattens the sacrum (enlarging the pelvic outlet), while suprapubic pressure dislodges the anterior shoulder from behind the pubic symphysis 1, 2

Clarifying the Question: Prevention vs. Management

Important distinction: The question asks about "preventing" shoulder dystocia, but the clinical scenario describes a patient already in labor. True prevention would involve delivery planning decisions made before labor onset 4, 5:

• Prophylactic cesarean delivery may be considered for estimated fetal weights >4,500g in non-diabetic women, though this remains controversial 4
• Induction of labor is NOT recommended for suspected macrosomia, as it doubles cesarean risk without reducing shoulder dystocia 4, 5

Ranking the Maneuvers by Frequency of Use

Suprapubic pressure (Option D) is the correct answer based on frequency:

• Used in 90.2% of shoulder dystocia cases 3
• Applied as part of the initial HELPERR mnemonic sequence 2

Rubin maneuver (Option B) is a second-line internal rotation technique:

• Used in 22.4-34.6% of cases, with higher frequency in obese patients 3
• Involves placing fingers behind the anterior shoulder to rotate it toward the fetal chest 2

Woods screw maneuver (Option A) is another rotational technique:

• Less commonly documented in recent literature compared to Rubin 3
• Involves rotating the posterior shoulder forward in a corkscrew motion 2

Zavanelli maneuver (Option C) is a last-resort procedure:

• Involves cephalic replacement (pushing the fetal head back into the vagina) followed by cesarean delivery 2
• Reserved for cases where all other maneuvers fail 2
• Rarely performed due to its complexity and associated risks 2

Practical Algorithm for This Patient

If shoulder dystocia occurs during delivery:

1. Call for help immediately - announce "shoulder dystocia" clearly 1, 2
2. McRoberts position - hyperflex maternal thighs onto abdomen 1, 2, 3
3. Suprapubic pressure - apply downward and lateral pressure above pubic symphysis 1, 2, 3
4. If unsuccessful, proceed to internal maneuvers: delivery of posterior arm (41.1% frequency) or Rubin maneuver 2, 3
5. Track time from head delivery to complete delivery 1

Critical Pitfalls to Avoid

• Never apply fundal pressure - this worsens shoulder impaction and increases injury risk 1, 2
• Avoid midpelvic operative delivery (forceps/vacuum) with suspected macrosomia - this increases shoulder dystocia risk to 21% in infants >4kg 6
• Do not perform excessive traction on the fetal head - this increases brachial plexus injury risk 1, 2