Health Library

Shoulder Dystocia

Definition

Shoulder dystocia is a problem during birth. The baby’s head has been born but the shoulders are stuck. The shoulder becomes trapped against the mother’s pubic bone.

Most babies will be able to be born safely with some help. Sometimes the baby may be stuck in the birth canal too long, which can cause some problems.

Problems for the baby may include:

  • Lack of oxygen
  • Broken arm or collarbone
  • Arm nerve damage
  • Paralysis

Problems for the mother may include:

  • Tearing or bruising of the cervix, rectum, or vagina
  • Bruising to the bladder
  • Severe bleeding
Shoulder Dystocia
Shoulder Dystocia
The baby's shoulder is lodged behind the mother's pubic bone.
Copyright © Nucleus Medical Media, Inc.

Causes

Shoulder dystocia happens because of one or both of the following:

  • Baby’s shoulders are too wide—larger babies are common in women with diabetes or late-term pregnancies
  • Mother's pelvic opening is too small for child
Narrow Pelvic Opening
Pelvis birth
Copyright © Nucleus Medical Media, Inc.

Risk Factors

Things that may increase a baby's chance of shoulder dystocia include:

  • Mother has diabetes
  • Mother is significantly overweight
  • Mother has small stature which may mean small pelvis
  • A very large baby
  • Shoulder dystocia in previous birth

Signs and Symptoms

There are no symptoms of shoulder dystocia.

Diagnosis

The doctor or midwife will know when the birth process stops after the head is born.

Prenatal tests will estimate the size of the fetus and the mother’s pelvis. These tests may show a risk for shoulder dystocia.

An ultrasound may be done before labor. The doctor will be able to see if the baby is too large to fit safely through the birth canal. A vaginal delivery may not be a safe method if the baby is too large.

Treatment

The care team will act fast if a shoulder dystocia occurs. The goal is to release the baby as fast as possible. This will allow the vaginal birth to continue. The doctor or midwife may:

  • Reposition the mother
  • Reposition the baby to try to move the shoulder away from the bone

A C-section may be needed if the baby remains stuck in the birth canal.

Prevention

Shoulder dystocia cannot always be prevented. If you have a high risk of shoulder dystocia the doctor may offer:

  • Early induced labor—the baby will be smaller
  • Planned C-section

Resources

American Congress of Obstetricians and Gynecologists
http://www.acog.org

American Pregnancy Association
http://www.americanpregnancy.org

Canadian Resources

The Society of Obstetricians and Gynaecologists of Canada
http://www.sogc.org

Women's Health Matters
http://www.womenshealthmatters.ca

References

American College of Obstetricians and Gynecologists (College), Society for Maternal-Fetal Medicine, Caughey AB, Cahill AG, Guise JM, Rouse DJ. Safe prevention of the primary cesarean delivery. Am J Obstet Gynecol. 2014 Mar;210(3):179-93. Reaffirmed 2016.

Cesarean section. EBSCO DynaMed website. Available at: https://www.dynamed.com/procedure/cesarean-section. Updated March 5, 2020. Accessed March 19, 2020.

National Institute for Health and Clinical Excellence (NICE). Caesarean section. NICE 2011 Nov:CG132PDF, summary can be found in BMJ 2011 Nov 23;343:d7108.

World Health Organization. Managing complications in pregnancy and childbirth: a guide for midwives and doctors. World Health Organization website. Available at: http://whqlibdoc.who.int/publications/2007/9241545879%5Feng.pdf. Updated 2007. Accessed March 19, 2020.