Obs Emergencies - Shoulder Dystocia Flashcards
What is shoulder dystocia?
Shoulder dystocia is defined by a delay in delivery of the shoulders following the head during a vaginal delivery with the next contraction after using normal traction.
Shoulder dystocia occurs when after delivery of the head the anterior shoulder becomes impacted on the pubic symphysis of the mother (or rarely posterior shoulder on sacral promontory.
It is an obstetric emergency, with an incidence of approximately 0.6-0.7% in all deliveries.
What are the risk factors for shoulder dystocia?
Pre-labour:
1. Previous shoulder dystocia x10
2. Macrosomia (fetal weight above 4.5kg)
3. Diabetes
4. Maternal BMI >30
5. Induction of Labour
Intra-labour:
1. Prolonged 1st stage of labour
2. Secondary arrest
3. Prolonged 2nd stage of labour
4. Augmentation of labour with oxytocin
5. Assisted vaginal deliver e.g. forceps, ventouse
Impossible to predict or prevent
What are the clinical symptoms of Shoulder dystocia?
Shoulder dystocia is defined by a delay in delivery of the shoulders following the head during a vaginal delivery with the next contraction after using normal traction.
On examination, signs that may occur to aid the diagnosis are:
- Difficulty in delivery of the fetal head or chin.
- Failure of restitution – the fetal remains in the occipital-anterior position after delivery by extension and therefore does not ‘turn to look to the side’.
- ‘Turtle Neck‘ sign – the fetal head retracts slightly back into the pelvis, so that the neck is no longer visible, akin to a turtle retreated into its shell.
What are the complications of shoulder dystocia?
Maternal – 3rd or 4th degree tears (3-4%), post-partum haemorrhage (11%).
Fetal – humerus or clavicle fracture, brachial plexus injury (2-16%), hypoxic brain injury.
- A delay in delivery of the shoulders results in fetal hypoxia that is proportional to the time of delay to complete delivery. Can lead to death. (Due to cord compression)
- Applying traction on the fetal head can result in fetal brachial plexus injury, and is major cause for litigation in obstetrics. (Erbs C5-C6, klumpke palse C8-T1)
- Fetal clavicle/ humerus fracture
- Maternal perineal injury, PPH
What is the management of Shoulder Dystocia?
- Call for help - MDT
- Advise the mother to stop pushing as can worsen the impaction
- Avoid downwards traction on the fetal head as increases risk of Brachial plexus injury - routine axial pressure best
- Consider episiotomy - will not relieve the obstruction but will improve access for manoeuvres
First Line Manoeuvres:
1. McRobert’s Manoeuvre 90% success rate
2. Suprapubic pressure - pressure behind anterior shoulder
Second Line Manoeuvres (Internal):
1. Posterior Arm - insert hand posteriorly into sacral hollow and grasp posterior arm to deliver.
2. Internal rotation - apply pressure simultaneously in front of one shoulder and behind the other to move baby 180 degrees or into an oblique position.
3. Roll onto all 4s and repeat - (this may widen the pelvic outlet as the legs are abducted and flexed).
Last Resort:
1. Cleidotomy – fracturing the fetal clavicle.
2. Symphysiotomy – cutting the pubic symphysis.
3. Zavenelli – returning the fetal head to the pelvis for delivery of the baby via caesarean section.
Post-delivery tips for shoulder dystocia:
After delivery of the fetus, active management of the 3rd stage of labour is recommended (due to increased risk of PPH). A PR examination should be performed to exclude a 3rd degree tear.
Shoulder dystocia can be a traumatic experience, particularly if the women does not have regional anaesthesia. Debrief the mother and birth partner(s), and advise them of the risk of recurrence with any subsequent delivery.
Consider a physiotherapist review before discharge, as women are at increased risk of pelvic floor weakness/3rd degree tear, musculoskeletal pain and temporary nerve damage.
Additionally, a paediatric review is recommended before discharge to assess for brachial plexus injury, humeral fracture or hypoxic brain injury.
