What is shoulder dystocia?
Shoulder dystocia occurs unexpectedly during childbirth and happens when the baby’s head has been born but one of the shoulders becomes stuck behind the mother’s pelvic bone, preventing the birth of the baby’s body.
Shoulder dystocia can occur during any vaginal birth. Sometimes, there can also be difficulty delivering the baby’s shoulders at a caesarean birth. In a normal birth there is usually a small delay between the delivery of the baby’s head and body but in shoulder dystocia the delay is longer than normal. How long this delay is will depend on how easy it is to overcome.
Why is it an emergency?
During birth, when the baby’s head is born, the baby cannot start breathing until it’s body is also born. In this situation the baby’s shoulders need to be quickly released so that the baby’s body can be born and the baby can start breathing air into his or her lungs.
How common is shoulder dystocia?
Shoulder dystocia occurs in about one in 200 births - 0.5 per cent.
Can shoulder dystocia be anticipated?
At every birth there is a small risk of shoulder dystocia and, in most instances, it is not possible to identify who it will happen to or why it occurs.
Some features may suggest when a difficult birth might occur such as when the:
- baby is large
- mother has diabetes
- mother had a previous baby with a shoulder dystocia
- labour is induced
- progress of labour is slow.
Shoulder dystocia has been linked to the birth of large babies; however, most large babies over 4.5 kilograms do not have a difficult birth. We also know that ultrasound scanning is not an accurate predictor of birth weight towards the end of pregnancy, particularly in large babies. At least half of all the babies who have shoulder dystocia weigh less than four kilograms.
Obstetricians and midwives know that in every birth there is a small possibility of shoulder dystocia and it is difficult to be certain about which women are likely to have this complication.
Can shoulder dystocia be prevented?
In most instances, shoulder dystocia cannot be prevented because it usually cannot be predicted.
Even if the baby is suspected to be large during pregnancy most mothers will still be able to have a normal vaginal birth.
Caesarean birth and early induction of labour are not routinely recommended as there are other risks associated with these for mother and baby which are also important to consider.
What happened when your baby had a shoulder dystocia?
When your baby’s head was delivered it became clear that the baby’s shoulders would not follow as they should. This is an emergency and your midwife will have called for help. Additional staff, including an obstetrician, midwives and a baby doctor (paediatrician), came into the delivery room to help. This would have been a very scary time for you and your support people.
The steps required to manage this situation may have included repositioning you which can help to widen the birth canal to give your baby more room, enabling your baby to be born.
You may have been asked to lie on your back with your legs pushed towards your tummy. This is known as the McRoberts’ manoeuvre.
Often babies will be born with this manoeuvre alone, but if not, after a short time, some other things may have been tried including:
- pressing on your tummy just above the pelvic bone to try to release your baby's shoulder
- making a cut (episiotomy) to enlarge your vaginal opening
- trying to move your baby within the birth canal to free the shoulders so that the baby's body could be born
- moving you onto your hands and knees.
Rarely, if none of these steps work, an emergency caesarean section is performed but this is a last resort as it is difficult to do in this situation and takes time to organise.
These are specific manoeuvres to help to release the baby’s shoulder and allow a safe birth. All obstetricians and midwives who attend births are familiar with these manoeuvres, which are practised regularly in all maternity units.
What could shoulder dystocia mean for a mother and her baby?
After the birth, you, and your baby, would have been carefully monitored because there are some risks associated with this complication.
For the baby
- The nerves in the neck called the brachial plexus, provide movement and feeling to the arm. When the baby's shoulder becomes stuck in the pelvis at the time the head is born, these nerves in the baby's neck may become stretched. Up to one in ten babies who have shoulder dystocia have brachial plexus injury. This injury may cause loss of movement (paralysis) to the baby's arm but, in most cases, this is temporary and movement will return within hours or days. A small number of babies (one in 100) who have shoulder dystocia will experience permanent damage.
- Shoulder dystocia can cause other injuries including fractures of the baby's arm or shoulder. In the vast majority of cases, these heal without any problems.
- Sadly, in some situations, even with receiving the best care, a baby can suffer brain damage, if he or she is not getting enough oxygen and can even die.
For the mother
- Vaginal tears can occur during the birth of the baby. This tear may extend to the rectum (third or fourth degree tear) or to the vaginal wall (vaginal laceration). These would have been repaired once the placenta was delivered.
- Heavy bleeding (postpartum haemorrhage). About one in ten (10%) women are affected by heavy bleeding after a birth complicated by shoulder dystocia. To avoid this, additional medications are often recommended. Some women may require other treatment and/or a blood transfusion.
- Emotional impact. After experiencing shoulder dystocia during childbirth, some mothers feel responsible for any harm that occurred to the baby. There is no evidence to suggest that this complication occurred as a result of anything you did, or did not do, during labour. Shoulder dystocia should not affect your chances of conceiving but it may take a while before you feel ready to try again.
What about next time?
The doctor looking after you will discuss what happened at your baby’s birth and answer your questions. They will discuss what to expect with regard to your recovery if you have sustained any injuries. They will also discuss any investigations which may help to identify if there were risk factors, which would be important to know for your next birth e.g. if you may have had diabetes. You will be advised what this might mean for future births.When a mother has previously had a birth complicated by a significant shoulder dystocia, the obstetrician may discuss having a caesarean birth next time.
© 2010 Mater Misericordiae Ltd. ACN 096 708 922
Mater acknowledges consumer consultation in the development of this patient information.
Last modified 12/11/2015.