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.
Shoulder dystocia is often caused by macrosomia secondary to gestational diabetes.
Presentation
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.
Management
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 can be used to enlarge the vaginal opening and reduce the risk of perineal tears. It is not always necessary.
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.
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.
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.
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.
Zavanelli manoeuver involves pushing the baby’s head back into the vagina so that the baby can be delivered by emergency caesarean section.
Complications
The key complications of shoulder dystocia are:
- Fetal hypoxia (and subsequent cerebral palsy)
- Brachial plexus injury and Erb’s palsy
- Perineal tears
- Postpartum haemorrhage
Last updated September 2020