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Pregnancy and birth

Shoulder dystocia: what it is and how maternity teams manage it

Shoulder dystocia happens when a baby's head is born but a shoulder stays caught behind the mother's pubic bone, delaying the rest of the birth. It is an obstetric emergency that midwives and doctors train for. Most babies recover fully, though some have a temporary arm weakness.

Last checked: 2026-10-03

Key facts

At a glance.

  • Frequency

    Around 1 in 150 vaginal births, about 0.7 per cent.

  • Cannot always be predicted

    About half of cases occur in babies weighing less than 4 kg.

  • Nerve stretch

    About 1 in 10 affected babies has a brachial plexus injury, which is usually temporary.

  • Repeat risk

    Around 1 in 10 women who have had shoulder dystocia have it again.

  • Emergency teamwork

    Extra staff are called and set manoeuvres are used in a fixed order.

What is happening during the birth

In a normal birth the baby's shoulders turn and slip under the pubic bone after the head is delivered. In shoulder dystocia the front shoulder cannot get past, so the body does not follow the head. The delay matters because the umbilical cord can be squeezed, and the baby cannot breathe until the chest is delivered. That is why the team works quickly and calmly through a set sequence.

Risk factors and why it is hard to predict

Shoulder dystocia is more likely in some situations, but the RCOG points out that half of the cases involve babies under 4 kg, so no scan or measurement can reliably predict it.

  • A previous shoulder dystocia.

  • Diabetes in the mother, including gestational diabetes.

  • A BMI of 30 or more.

  • Induced labour or a long labour.

  • An instrumental delivery with forceps or ventouse.

  • A larger baby, although size alone is an imperfect guide.

What the team does

When the problem is recognised, the midwife calls for help and may ask you to stop pushing for a moment. The first-line manoeuvre is the McRoberts position: you lie back with your legs pushed outwards and up towards your chest, which widens the pelvic outlet. Pressure may be applied just above the pubic bone to turn the shoulder.

If that does not free the baby, the team may consider an episiotomy to make room for the hands to work inside, internal manoeuvres to rotate the shoulders, or asking you to move onto all fours. The order and method are chosen by the senior clinician. Afterwards the baby is assessed by a paediatric team.

Effects on the baby

About one in ten babies who experience shoulder dystocia has a brachial plexus injury, a stretch of the nerves that run from the neck to the arm. The best known pattern, Erb's palsy, affects the upper arm. Most recover within weeks or months, and physiotherapy supports the arm in the meantime.

Fractures of the collarbone or upper arm bone can occur and usually heal well. Rarely, a delay in delivering the body leads to lack of oxygen and brain injury, which is why speed matters.

Effects on the mother

The mother has a higher chance of heavy tearing and of postpartum haemorrhage after shoulder dystocia, and some women need a transfusion. Physical recovery is only part of the picture: an emergency birth can feel frightening, and some people have symptoms of distress or post-traumatic stress afterwards. A debrief with a midwife or obstetrician helps you understand what happened and why.

Planning the next birth

The RCOG says around one in ten women who have had shoulder dystocia have it again. Before the next birth, your obstetrician will go through the notes of the previous one, the baby's weight and the nature of any injury, and discuss induction, planned caesarean or waiting for spontaneous labour. A planned caesarean is a legitimate choice, and so is a vaginal birth with an experienced team prepared.

If you have diabetes, good blood sugar control in pregnancy and regular growth scans contribute to the plan.

Frequently asked

Questions people ask.

Quick, plain-English answers to the questions we hear most.

  • Is shoulder dystocia my fault?

    No. It relates to the shape of the pelvis, the baby's size and position and the way the birth progresses, none of which you control.

  • Can it be found on a scan?

    Not reliably. Scans estimate baby weight but half the cases happen in babies under 4 kg, so the RCOG says it cannot be predicted with confidence.

  • Will my baby be injured?

    Most babies are not. About 1 in 10 has a nerve stretch, and these are usually temporary.

  • What is Erb's palsy?

    A weakness of the arm caused by stretching of nerves in the neck. Physiotherapy is the usual treatment and many babies recover fully.

  • Why was I asked to lie on my back with my knees up?

    It is the McRoberts position, which widens the pelvic outlet and often frees the shoulder.

  • Why did they cut an episiotomy?

    To give the clinician space to use internal manoeuvres. It is used selectively, not for every shoulder dystocia.

  • Will it happen again?

    Around 1 in 10 women have a repeat. Your next birth is planned with this in mind.

  • Does having a big baby mean a caesarean?

    Not automatically. Discussion depends on diabetes, previous births and your own preferences, and a suspected large baby alone is not a reason for caesarean in every case.

  • Where can I get support after a frightening birth?

    Ask your midwife for a debrief, and see your GP if distress continues; there are NHS talking therapies and perinatal mental health services.

Where this comes from

Sources and checking.

This guide is for information, not medical advice.

Your GP or consultant knows your history and can tell you which parts apply to you. If your symptoms are severe, rapidly worsening, or come with red-flag features, seek urgent medical care. Figures and availability change, so treat them as a guide and confirm with the provider.

Published 2026-10-03, next review 2027-10-03.

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