Shoulder Dystocia Flashcards
What is shoulder dystocia?
Shoulder dystocia is when the anterior shoulder of the baby becomes stuck behind the pubic symphysis of the pelvis, after the head has been delivered. This requires additional obstetric manoeuvres to enable delivery of the rest of the body. Shoulder dystocia is an obstetric emergency.
What are the risk factors for shoulder dystocia?
Shoulder dystocia is often caused by macrosomia secondary to gestational diabetes.
How does shoulder dystocia present?
Shoulder dystocia presents with difficulty delivering the face and head, and obstruction in delivering the shoulders after delivery of the head. There may be failure of restitution, where the head remains face downwards (occipito-anterior) and does not turn sideways as expected after delivery of the head. The turtle-neck sign is where the head is delivered but then retracts back into the vagina.
Briefly describe the management of shoulder dystocia
Shoulder dystocia is an obstetric emergency and needs to be managed by experienced midwives and obstetricians. The first step is to get help, including anaesthetics and paediatrics. Several techniques can be used to manage the condition and deliver the baby:
- Episiotomy
- McRoberts manoeuvre
- Pressure to the anterior shoulder
- Rubins manoeuvre
- Wood’s screw manoeuvre
- Zavanelli manoeuver
What is the role of episiotomy in shoulder dystocia?
Episiotomy can be used to enlarge the vaginal opening and reduce the risk of perineal tears. It is not always necessary.
What is the role of McRoberts manoeuvre in shoulder dystocia?
McRoberts manoeuvre involves hyperflexion of the mother at the hip (bringing her knees to her abdomen). This provides a posterior pelvic tilt, lifting the pubic symphysis up and out of the way.
What is the role of pressure to the anterior shoulder in shoulder dystocia?
Pressure to the anterior shoulder involves pressing on the suprapubic region of the abdomen. This puts pressure on the posterior aspect of the baby’s anterior shoulder, to encourage it down and under the pubic symphysis.
What is the role of Rubins manoeuvre in shoulder dystocia?
Rubins manoeuvre involves reaching into the vagina to put pressure on the posterior aspect of the baby’s anterior shoulder to help it move under the pubic symphysis.
What is the role of Wood’s screw manoeuvre in shoulder dystocia?
Wood’s screw manoeuvre is performed during a Rubins manoeuvre. The other hand is used to reach in the vagina and put pressure on the anterior aspect of the posterior shoulder. The top shoulder is pushed forwards, and the bottom shoulder is pushed backwards, rotating the baby and helping delivery. If this does not work, the reverse motion can be tried, pushing the top shoulder backwards and the bottom shoulder forwards.
What is the role of Zavanelli manoeuver in shoulder dystocia?
Zavanelli manoeuver involves pushing the baby’s head back into the vagina so that the baby can be delivered by emergency caesarean section.
What are the complication of shoulder dystocia?
The key complications of shoulder dystocia are:
- Fetal hypoxia (and subsequent cerebral palsy)
- Brachial plexus injury and Erb’s palsy
- Perineal tears
- Postpartum haemorrhage
Briefly describe Erb’s Palsy
An Erbs palsy is the result of injury to the C5/C6 nerves in the brachial plexus during birth. It is associated with shoulder dystocia, traumatic or instrumental delivery and large birth weight.
Damaged to the C5/C6 nerves leads to weakness of shoulder abduction and external rotation, arm flexion and finger extension. This leads to the affected arm having a “waiters tip” appearance:
- Internally rotated shoulder
- Extended elbow
- Flexed wrist facing backwards (pronated)
- Lack of movement in the affected arm
Function normally returns spontaneously within a few months. If function does not return then they may required neurosurgical input.
