Shoulder dystocia: what is it and why does it happen?
Shoulder dystocia happens when a baby’s shoulder gets stuck during birth. It’s rare, but is more common with bigger babies (macrosomia) and bigger mums. It can feel alarming for parents in the delivery room because your baby needs to be freed quickly so it counts as an emergency. But the vast majority of babies are delivered safely with no lasting ill-effects.
What is shoulder dystocia?
After your baby’s head emerges from the birth canal, their shoulders usually follow in the next contraction. Often the baby will turn slightly so they’re at the best angle to allow the shoulders through.
But sometimes one shoulder will get stuck behind your pelvic bone, and the midwife and/or doctor will need to take swift action to release it, so the rest of your baby’s body can be born safely and get the oxygen it needs.
Shoulder dystocia happens in around one in 150 births, so it’s quite rare.
Who is at risk of shoulder dystocia?
It’s pretty difficult to predict who will have shoulder dystocia as it’s fairly random. But it is more common in bigger babies over 4kg/8lbs 13oz (having a large baby is called macrosomia). That’s because they have wider shoulders to fit through. But if you know you’re having a large baby, don’t panic: more than half the cases of shoulder dystocia happen with babies under 4kg.
Other risk factors are:
- If you’ve had a labour with shoulder dystocia before. Your doctor may suggest a Caesarean delivery if it was difficult to free the shoulder last time
- If you are overweight (especially with a body mass index of 30 or more).
- If you have gestational diabetes (that’s because your baby is likely to be bigger)
- If your labour is induced
- If your labour is long and you need forceps or ventouse
What will happen?
Things will happen very fast if your baby is delivered with shoulder dystocia – which is why it can feel alarming for parents. That’s because your baby’s shoulder needs to be freed quickly so they can be born and start using their lungs to breathe.
The midwife will press the emergency buzzer or call for help, and 3 or 4 medical staff, including a paediatrician, will arrive in the delivery room.
This is usually what happens next:
- They’ll ask you to stop pushing. Then they’ll get you to lie on your back with your legs pushed outwards and upwards to give the baby more room inside you.
- The obstetrician or midwife will press just above your pubic bone to try to release the trapped shoulder
- Sometimes they may make a cut (episiotomy)
Most babies are born safely by now. But if that didn’t work, you might be asked to roll onto all fours which can help free the shoulder. Or the midwife/doctor will put their hand inside you to help release it
Will everything be ok?
Most babies and mums are absolutely fine after shoulder dystocia, although it can be traumatic and upsetting to have a difficult birth
But there can be some after-effects:
- You’re more likely to have vaginal tears and heavier bleeding afterwards
Even if everything went fine in the end, it can feel shocking and upsetting to have such a traumatic start to your baby’s life. Some mums feel depressed, angry and guilty (even though they couldn’t have done anything to avoid it). Don’t suffer in silence: make sure you talk to your midwife, doctor or health visitor and get the help you need
One in 10 babies with shoulder dystocia will have brachial plexus injury – that’s when the nerves in their neck are stretched and they may not be able to move their arm for a few hours. Sometimes it can take a few days to go away, but permanent damage is very rare
Sometimes the baby’s collar bone or arm is fractured during the efforts to free them, but these heal quickly
Being stuck in the birth canal can affect a baby’s supply of oxygen if it takes a long time to free them. In a very few, highly exceptional cases, this may result in some brain damage