At an otherwise normal delivery, just after the baby's head has emerged, the neck suddenly retracts back against the mother's perineum causing the baby's cheeks to puff out. The experienced midwife knows at this point that the baby's anterior shoulder is caught on the mother's pubic bone and if he or she is unable to free up the shoulder within a few minutes the baby will suffer irreversible brain damage or death. Shoulder dystocia occurs in approximately one half of one percent of all deliveries. The larger the baby, the more likely it is to occur. However, even with very large babies shoulder dystocia occurs only occasionally and sporadically. Therefore a midwife never knows when it will be encountered. The most common serious complication following a shoulder dystocia delivery is brachial plexus injury. This is when the nerves in a baby's neck--the brachial plexus--are temporarily or permanently damaged. The nerves of the brachial plexus control the function of the arm and hand. Injury to the upper part of the brachial plexus is called Erb palsy while injury to the lower nerves of the plexus is called Klumpke palsy. Both can cause significant, lifelong disability. Because of the gravity and unexpectedness of shoulder dystocia it has long been a major area of concern. Yet despite the hundreds of published studies about shoulder dystocia there still are multiple, important unanswered questions: - Is shoulder dystocia predictable?
- Can it be prevented?
- Is there anything that can be done when it does occur to prevent brachial plexus nerve damage?
- If there is an injury, was it caused by mismanagement on the part of the midwife while attempting to resolve the shoulder dystocia or was it an inevitable consequence of the shoulder dystocia?
Risk factors for shoulder dystocia:
Maternal obesity (it is thought that fatty deposits are laid down in the pelvis)
Maternal diabetes (this often leads to macrosomia - larger babies)
Post dates
Previous shoulder dystocia or big baby
Prolonged 1st and/or 2nd stage of labour (delayed progress can indicate a larger baby and problems with the natural mechanism of labour)
Operative delivery (this interferes with the natural mechanism of labour)
Small or abnormal pelvis / short stature.
These risk factors may or may not be present, and often the first indicator of a shoulder dystocia is failure of the baby's chin to escape the perineum, 'turtle-necking', where the baby's head appears to retract back into the pelvis, and failure of the baby's head to undergo restitution (Medforth, Battersby, Evans, Marsh and Walker, 2006).
Complications of shoulder dystocia include:
Maternal - vaginal lacerations, uterine rupture, haemorrhage due to uterine atony or birth canal trauma, symphseal diathesis and transient femoral neuropathy.
Fetal/Neonatal - Brachial plexus injury, fractures, hypoxia, death.
Management of shoulder dystocia: HELPERR is the mnemonic that is used on recognition of a shoulder dystocia:
H - obtain
help, in the form of the most senior on call obstetrician, paediatrician, anaesthetist, midwives and support workers. Record-keeping is essential. It is important that a scribe is present, and the time of delivery of the head is noted.
E - evaluate for
episiotomy (ensure episiotomy scissors are open, symphysiotomy tray is available).
L -
legs. The McRoberts manoeuvre should be facilitated, which involves hyperflexion of maternal thighs, so that the woman's thighs are resting on her abdominal wall. The bed should be flat, with pillows removed.
P - external manual suprapubic
pressure. 30 seconds of firm constant pressure, followed by intermittent rocking. This aims to rotate the anterior shoulder, and so it is important to ascertain the position of the baby, so that pressure can be applied to the posterior aspect of the anterior shoulder.
E -
Enter. Enter the vagina to perform a series of manoeuvres, starting with: Rubin's manoeuvre, Wood's screw manoeuvre and Reverse Wood's Screw manoeuvre.
R -
Remove posterior arm. - The practitioners hand should enter posteriorly, follow the arm to flex it at the elbow, grasp the hand of the fetus and sweep the arm across the face and chest to deliver it.
R -
Roll the patient onto hands and knees and repeat the above manoeuvres.
70% of shoulder dystocia's are delivered following the McRober's manoeuvre and suprapubic pressure.
If the McRobert's manoeuvre, suprapubic pressure and a 'generous' episiotomy has failed, and reasonable obstetric assistance is not available, it is reasonable to try delivering in a squatting position or on all fours, using downward traction to release the posterior shoulder. (CESDI, 1998).
Other manoeuvres that may be attempted, but only by an obstetrician, include the zavanelli technique - replacement of the head in the birth canal and delivery by caesarean section. Symphysiotomy.
It is important to avoid the following at all times in the management of a shoulder dystocia:
fundal pressure
increasingly forceful traction on the head
Fetal blood pH:
pH declines at 0.04 units per minute following delivery of the head.
pH is reduced by 0.28 units following 7 minutes after delivery of the head.
7.25 is regarded as normal pH.
Below a pH of 7.0, it is increasingly difficult to resuscitate the infant.
47% of shoulder dystocia's death occurs in 5 minutes
(ALSO, 2000).
McRobert's Manoevre 
Suprapubic pressure 
Rubin's Manoeuvre 
Wood's Screw Manoeuvre 
Reverse Wood's Screw Manoeuvre 
Remove Posterior Arm 
Advanced Life Support in Obstetrics (ALSO). (2000) Advanced
Life Support in Obstetrics Manual. 4th ed. Kansas: American Academy of Family Physicians.
Confidential Equiry into Stillbirths and Deaths in Infancy (CESDI). (1998)
5th Annual Report. London: The Maternal and Child Health Research Consortium.
Medforth, J., Battersby, S., Evans, M., Marsh, B. and Walker, A. (2006)
Oxford Handbook of Midwifery. Oxford: Oxford University Press.
www.thewomens.org.au http://www.shoulderdystociainfo.com/ Further Resources Videos:-Websites:-