Shoulder Dystocia

!!! OBSTETRIC EMERGENCY !!!

Complication of a vaginal cephalic delivery. Difficulty to deliver the fetal body after the head, due to impaction of shoulder (usually anterior) behind pubis symphysis. 

The longer delivery of the shoulders is delayed, the greater the extent of fetal hypoxia. 

Largely unpredictable and unpreventable event. 

Presentation

• Turtle neck sign

  • • The head appears and then retracts like a turtle head retracting into its shell 

• Failure of restitution

• • Following delivery of the fetus's head it does not ‘turn to look to the side’ (as expected) and remains in the occipital-anterior position 

Risk Factors 

• Previous shoulder dystocia 

• Fetal macrosomia 

• Post-dates fetus 

• Maternal (gestational) diabetes 

• Short maternal stature 

• Abnormal maternal pelvic anatomy 

• Maternal BMI>35 

• Prolonged first or second stage of labour 

• Induction of labour 

• Instrumental delivery 

Complications

Fetal:

• Brachial plexus palsy (Erb's palsy - adduction and internal rotation of arm) via applying traction on fetal head 

• Hypoxic brain injury 

• Fracture of clavicle or humerus 

• Fatal acidosis 

Maternal:

• Third and fourth degree tears - anal sphincter damage 

• Postpartum haemorrhage 

Management

1. Call for help - this is an emergency and senior attendance is needed 

2. Advise the mother to stop pushing to avoid worsening the impaction 

3. Avoid:

   1. • Downwards traction of fetal head - keep the head in line with the baby's spine 

      • Applying fundal pressure - risk of uterine rupture 

4. First line MANOEUVRES - works in 90% of cases 

   1. • McRobert's (maternal knee to chest position - hyperflexion of hips)

      • Suprapubic pressure 

5. Internal maneouvres are required if this has failed 

   1. • Wood's screw manoeuvre 

      • Grasping posterior arm

6. Post delivery care 

   1. • PR exam to exclude 3rd degree tear 

      • Debrief mother - advise future risk of recurrence 

      • Physiotherapist review - risk of pelvic floor weakness/3rd degree tear, MSK pain and temporary nerve damage