Shoulder dystocia is a potentially dangerous childbirth complication. It occurs when an infant’s head emerges, but their shoulders remain trapped behind the pubic bone of the birthing parent.

Shoulder dystocia is relatively uncommon, occurring in 0.5% to 1% of vaginal deliveries.

When the baby’s head is born for longer than a minute and the shoulders do not emerge, medical providers consider it a shoulder dystocia. This is a medical emergency requiring immediate treatment. It can cause serious complications for both parents and babies.

Read on to learn about what shoulder dystocia is, including complications, treatment options, and more.

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Shoulder dystocia causes a baby to get stuck during birth.

Specifically, their head appears, but at least one shoulder remains stuck behind the birthing parent’s pubic bone. This can cause serious injuries, especially if the baby remains stuck for an extended period. Prompt intervention to deliver the infant can reduce potential risks.

In most cases, a doctor or midwife considers the condition to be shoulder dystocia if the baby’s shoulders do not emerge within 1 minute of the birth of the head.

Some people can manage this condition relatively easily with a change of position. A doctor will advise an individual on changing position and help them deliver the baby safely.

However, in severe cases, they may advise more significant intervention. They may need to break an infant’s collarbone to deliver them or perform an emergency cesarean delivery.

If the delivery is quick, infants with shoulder dystocia are often born without injuries. However, the longer there are delays to delivery, the more likely they are to experience complications.

The most common complication is a brachial plexus injury, which affects 3–17% of babies. This causes damage to the nerves around the shoulder and neck.

Infants with this complication may have reduced movement or difficulties moving their arms or hands. Most recover within a few months, but some need surgery, and a few have long-term mobility issues.

Some other complications include:

  • Clavicle fracture: This affects 1% to 9.5% of infants with shoulder dystocia.
  • Humerus fracture: This affects 1% to 4.2% of infants with shoulder dystocia.
  • Hypoxic brain injury: This is very rare, affecting about 0.3% of infants with shoulder dystocia. It occurs when oxygen to the brain becomes restricted.
  • Death: This is very rare, affecting 0.35% of infants with shoulder dystocia.

A 2017 study followed healthcare professionals who implemented specific protocols for shoulder dystocia. These protocols enabled delivery in less than 3 minutes in 99% of cases, greatly reducing complications. There were 1.4 injuries to babies per 1,000 births.

Many different management techniques can enable safe delivery. Most involve changing position and moving the baby.

These techniques include:

  • McRoberts maneuver: This first-line intervention involves the birthing person bending their knees and flexing their thighs back toward the abdomen. This can increase space in the birthing canal.
  • Suprapubic pressure: People sometimes use this method alongside position changes. It involves placing downward pressure on the pubic area to encourage delivery.
  • Gaskin maneuver: A second-line option if McRobert’s maneuver fails, this involves placing the individual on their hands and knees. A healthcare professional then inserts a hand into the vagina to apply downward pressure on the infant’s shoulder.
  • Moving the baby: Several interventions involve attempting to move the baby. For example, a doctor may ask the birthing person to adopt a position to widen the birthing canal. A healthcare professional may then deliver one of the baby’s arms, making it easier for them to pass through the birth canal.

If these interventions are unsuccessful, a doctor may resort to significant measures. While these may cause injuries to both the birthing parent and the baby, in some cases, they are necessary.

These interventions include:

  • Clavicular fracture: A doctor may reach into the birthing canal and intentionally fracture the baby’s collarbone, making it easier to move them out.
  • Zavanelli maneuver: This involves rotating the baby back up into the uterus for an emergency cesarean delivery.
  • Abdominal rescue: This involves placing a surgical incision low in the abdomen, so a doctor can rotate the baby, freeing them and making a vaginal delivery possible.
  • Symphysiotomy: This is typically a last resort measure. It involves widening the delivery space by cutting into the pubic cartilage. It can cause numerous complications for the birthing parent, but in some cases, it may be the best option for both parent and infant.

Shoulder dystocia occurs when the baby’s shoulder or shoulders cannot fit past the pubic bone during delivery. This often occurs when the baby is larger than average.

Risk factors, such as gestational diabetes, which increase the risk of a larger baby, also increase the risk of shoulder dystocia.

Shoulder dystocia affects 0.5% to 1% of vaginal deliveries.

However, when a baby weighs more than 4.5 kilograms (kg), the rate rises to 10%. In babies under 4 kg, the rate is about 1%. In slightly larger babies of 4 to 4.5 kg, the rate is 5%.

While size is a significant predictor of shoulder dystocia, at least half of cases occur in babies under 4.5 kg.

Risk factors for shoulder dystocia predict just 50–70% of cases, which means this complication can occur in any birth. Fetal macrosomia — when a baby’s birth weight is more than 8 pounds and 13 ounces — is the most significant risk factor. However, at least half of cases occur in pregnancies where the fetus is of a typical size.

Some other risk factors include:

  • use of epidural anesthesia
  • a prolonged second stage (pushing) of labor
  • giving birth to a male baby
  • significant weight gain during pregnancy
  • gestational diabetes
  • gestation longer than 42 weeks
  • pelvic stenosis
  • obesity in the birthing parent
  • vacuum or forceps-assisted vaginal birth

Shoulder dystocia is a medical emergency requiring immediate care. If a person is giving birth in the hospital and a doctor is not present, it is critical to get a doctor immediately.

Position changes may help during a home birth or accidental home birth. A birthing parent should try changing positions and encourage pushing. They should also immediately call 911.

Shoulder dystocia is a serious complication that requires prompt intervention. However, with adequate care, almost all babies are born, with most avoiding serious injury.

People with a history of shoulder dystocia have a significant risk of another shoulder dystocia. It is important to discuss this history with a healthcare professional and develop a treatment plan should this emergency arise.