Shoulder Dystocia: Diagnosis, Evaluation and Management

SUMMARY:

Shoulder dystocia is an obstetrical emergency. While there are associated risk factors, they are poor at predicting shoulder dystocia. The majority of cases will occur in women without diabetes whose offspring are within normal weight range. Nor is there any evidence that shoulder dystocia can be prevented. Complications include PPH and brachial plexus injuries. ACOG published guidance in 2017 that has been reaffirmed (2019).

Diagnosis (ACOG):

Failure to deliver the fetal shoulder(s) with gentle downward traction on the fetal head, requiring additional obstetric maneuvers to effect delivery

Risk Factors

• Maternal
  • Prior history of shoulder dystocia
    • Universal prophylactic cesarean section is not recommended
    • Due to recurrence risk (1% to 16.7%), evaluate EFW, GA, glucose and severity of previous event
    • Patient discussion and careful delivery planning are recommended
  • Diabetes: GDM and pre-gestational diabetes
• Fetal
  • Macrosomia (see delivery recommendations below)
  • Large fetal chest relative to biparietal diameter (seen with diabetes)

Note: Despite known risk factors “…shoulder dystocia cannot be accurately predicted or prevented”

Evaluation:

• There are no ultrasound findings or labor patterns that are predictive of shoulder dystocia
• The classic “turtle sign” is “…suggestive, but not diagnostic, of the presence of shoulder dystocia”
• Diagnosis is based on clinical judgement when there is failure to deliver the fetal shoulders after initial traction attempts

Management  for Suspected Fetal Macrosomia (see Related ObG Topics below):

• Delivery <39 weeks gestation is not recommended without medical indication
• Elective cesarean delivery should be considered for the following
  • Without diabetes: estimated fetal weight of ≥5,000 gm
  • With diabetes: estimated fetal weight of ≥4,500 gm
• Induction
  • Not suggested for suspected fetal macrosomia as induction has not been shown to improve maternal or fetal outcomes
• Trial of labor
  • Suspected fetal macrosomia is not a contraindication to a trial of labor after cesarean delivery

Maneuvers (see videos in ‘Learn More – Primary Sources’ below):

• McRoberts maneuver: Best first step (Level B Evidence)
  • Maternal knees flexed and brought to chest while suprapubic pressure is applied
• Posterior Shoulder Delivery to reduce shoulder diameter
  • Next option if McRoberts unsuccessful
  • Decreases the diameter of the fetal shoulder girdle
• Additional techniques to deliver the posterior shoulder include the following
  • Rubin maneuver: Place hand on the back of the posterior fetal shoulder followed by anterior rotation towards the fetal face
  • Woods Screw maneuver: Apply pressure to anterior surface of the posterior shoulder with fetal rotation until anterior shoulder disengages from behind the maternal symphysis
  • Posterior axilla sling traction: Thread a size 12 or 14 French soft catheter around the posterior shoulder and apply moderate traction to the sling to deliver the shoulder
  • Gaskin all-fours maneuver (for women without anesthesia): With patient on hands and knees, apply gentle downward traction on the posterior shoulder or upward traction on the anterior shoulder
• ‘Last Resort’ maneuvers: Associated with significant maternal and/or fetal morbidity and mortality
  • Zavanelli maneuver: Head placed back in vaginal canal followed by cesarean section
  • Abdominal rescue: shoulder dislodged from above via hysterotomy
  • Intentional fetal clavicular fracture

Additional Considerations:

• Do not apply fundal pressure due to risk for uterine rupture
• Instruct patient to stop pushing until dystocia is resolved
• Evidence does not support use of routine episiotomy
  • Reserve for clinical situation where additional room may be needed for above maneuvers
• Documentation should be contemporaneous and include
  • Time of diagnosis
  • Management
  • Time of delivery
  • Sequelae
• Simulation Programs
  • Simulation is used to train healthcare personnel for particularly severe, high acuity events that are relatively infrequent
  • Simulation is effective in the setting of shoulder dystocia and improves
    • Communication | Use of maneuvers | Documentation

Note: Maneuvers may be repeated if not successful initially and in addition

…clinicians should use the maneuver most likely to result in successful delivery

No randomized controlled trials have compared maneuvers for shoulder dystocia alleviation

Brachial plexus injury can occur regardless of the procedures used to disimpact the shoulder(s) because all maneuvers can increase the degree of stretch on the brachial plexus

Learn More – Primary Sources

ACOG Practice Bulletin 178: Shoulder Dystocia

Johns Hopkins Medicine | Gynecology & Obstetrics: Shoulder Dystocia Simulation and Training Videos