Shoulder dystocia happens when the baby’s shoulder gets stuck behind the mother's pubic bone during birth. It’s a medical emergency because it can deprive the baby of oxygen.
What is shoulder dystocia?
During the second stage of labour, there is normally a pause after the baby’s head has been born but before the body comes out. When shoulder dystocia occurs, this delay is longer delay than normal. The baby will need emergency help to be born.
It happens when one of the baby’s shoulders gets stuck behind the mother’s pubic bone (the bone behind the pubic hair) or sacrum (the bone at the back of the pelvis, above the tailbone).
Shoulder dystocia happens in about 1 in every 200 births. It’s more common during a vaginal birth, but a baby’s shoulder can also get stuck during a caesarean.
Shoulder dystocia is a medical emergency. While the baby is stuck, they can’t breathe and the umbilical cord may be squeezed. They will need help to be born quickly so they can get enough oxygen.
Sometimes shoulder dystocia can lead to complications for the mother, including tears or a haemorrhage. The baby may have damage to the nerves that lead to the arm (called a 'brachial plexus' injury), or a fracture. It is rare for these complications to be permanent. Sadly, however, there’s a risk that lack of oxygen during birth can lead to brain damage or even death.
These complications are very rare, and doctors and midwives are highly trained to deal with shoulder dystocia if it happens.
Why does shoulder dystocia happen?
Shoulder dystocia can happen during any vaginal birth. It is usually because the baby is too big, because it is in the wrong position, or because the mother is in a position that restricts the room in the pelvis.
It’s impossible to predict whether shoulder dystocia will happen, but there are some things that make it more likely, including when you:
- experienced shoulder dystocia during a previous labour
- are having a large baby (called ‘fetal macrosomia’)
- are very overweight
- have diabetes
- have had labour induced, or other interventions are used during labour
Shoulder dystocia can also happen if the labour goes very quickly or very slowly.
What to expect if shoulder dystocia happens
If your doctor or midwife suspects shoulder dystocia, they will first tell you to stop pushing. They will immediately call for help, since you may need other specialist doctors to care for you or the baby.
Sometimes simply changing your position can free the shoulder. You might be asked to lie flat on your back with your knees pulled back as far as they can go. The midwife or doctor will gently press on your tummy to help free the baby’s shoulder. This is called the 'McRoberts manoeuvre'.
Another position that can work is if you get onto all fours. Sometimes the midwife or doctor will need to put their hand inside your vagina to free the baby’s body. You will need an episiotomy first.
In very rare cases, the doctor will need to break the baby’s collarbone to get them out. It will heal quickly afterwards. The other option is for you to have a caesarean under general anaesthetic. Once the anaesthetic has taken effect, the baby will be pushed back into your uterus and delivered through your tummy. Both of these options are a last resort.
After the birth
Most babies recover from shoulder dystocia very well. But because they may have been injured or deprived of oxygen, they may need to be watched more closely or spend time in the neonatal intensive care unit. Some babies will need physiotherapy, and you may need help with breastfeeding if your baby has been injured.
If you had a tear or haemorrhage, it will take some time for you to recover. It can also be hard emotionally if you have had a difficult birth. You might feel shocked, guilty or worried about your baby. Midwives, your doctor or a maternal child health nurse can help you deal with these feelings.
Your doctor will talk to you about why the shoulder dystocia might have happened. As you are at greater risk of it happening again, they may suggest you consider a planned caesarean next time around.
Preventing shoulder dystocia
Shoulder dystocia is unpredictable so there’s very little you can do to prevent it. Managing conditions like diabetes and watching your weight during pregnancy can help. If your baby is big, it may be a good idea to give birth lying on your side or on all fours.
For more information
If you are worried about shoulder dystocia or if you have experienced a difficult birth, call Pregnancy, Birth and Baby on 1800 882 436 to talk to a maternal child health nurse.
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Last reviewed: February 2019