Shoulder Dystocia
Shoulder dystocia is an unexpected emergency during vaginal birth where a baby's head delivers, but one of their shoulders gets stuck behind the mother's pelvic bone. This delay prevents the baby from moving through the birth canal and can increase the risk of injury to both the baby and the mother.
For most families, the birth still ends safely, but some babies may experience brachial plexus injuries, fractures, or lack of oxygen, potentially leading to complications like Erb's palsy, hypoxic-ischemic encephalopathy (HIE), or cerebral palsy.
What Is Shoulder Dystocia?
Shoulder dystocia occurs when the baby's head is delivered but the front (anterior) shoulder becomes impacted behind the mother's pubic bone. It can also happen when the back (posterior) shoulder becomes stuck on the sacrum.
Clinically, shoulder dystocia is diagnosed when gentle downward traction on the baby's head does not result in delivery of the shoulders, and additional obstetric maneuvers are required.
Shoulder dystocia must be recognized quickly and be given immediate medical attention. Every minute of delay increases pressure on the umbilical cord and chest, which can reduce oxygen flow to your baby.
How Common Is Shoulder Dystocia?
Shoulder dystocia is considered uncommon but not rare, occurring in roughly 0.2—3% of vaginal, head-first births. Since the condition cannot be accurately predicted, doctors and medical staff must always be trained and prepared for the possibility of it occurring during childbirth.
According to the Royal College of Obstetricians and Gynaecologists (RCOG), shoulder dystocia occurs in around 1 in 150 vaginal births (~0.7%). However, depending on infant and maternal risk factors, the rate of shoulder dystocia can vary widely.
Who Is at Higher Risk for Shoulder Dystocia?
Although most cases of shoulder dystocia happen in pregnancies that appeared low-risk without warning, there are certain infant and maternal risk factors that make it more likely, such as:
Fetal Macrosomia (Large Babies)
Babies weighing over 8 lbs 13 oz (4000 g) are diagnosed with macrosomia. Larger babies make vaginal births more difficult and increase the risk of shoulder dystocia. In fact, babies weighing between 8 lbs 13 oz and 9 lbs 14 oz (4500 g) increase risks by 5—9%, and those weighing more than 9 lbs 14 oz (4500 g) increase by 14—23%. Mothers who previously gave birth to a child with macrosomia and who give birth past the age of 35 are also at increased risk.
Maternal Diabetes
When the mother has gestational or pre-existing diabetes, babies tend to store more fat in the shoulders and upper body. If that baby is large and/or also diagnosed with macrosomia, the risk of shoulder dystocia is significantly increased. Some studies show a 2.5 to 6x increased risk of shoulder dystocia for babies with diabetic mothers.
Maternal Obesity and Pregnancy Weight
Mothers with obesity or significant weight gain during pregnancy have higher rates of large babies and longer, more difficult labors. This can increase the risk of shoulder dystocia.
Post-Term Pregnancy
Babies who go well past their due date may continue to grow and gain weight, especially in the shoulders, which can increase the chance of a tight fit in the birth canal.
Prolonged Second Stage of Labor (Pushing Phase)
When pushing goes on for a long time, especially with a larger baby, the chances of the shoulders getting wedged in the pelvis increase. Prolonged second stage often leads to more traction on the head or more frequent use of delivery tools.
Labor Induction and Augmentation (Pitocin Use)
Induction or strong augmentation (with the use of drugs such as Pitocin) of contractions in a pregnancy with risk factors such as a large baby or diabetes may lead to a tight fit in the pelvis. Labor progressing too fast and the baby not having enough time to rotate into an optimal position can increase risk.
What Are the Risks of Shoulder Dystocia?
While many babies with shoulder dystocia recover well, there are possible complications, injuries, and harmful outcomes that can affect both the baby and mother.
Risks for the Baby
- Brachial plexus injury (Erb's palsy or total plexus palsy) - About 2 to 16% of dystocia cases involve a brachial plexus injury, with most of them being temporary and around 10% resulting in permanent disability.
Studies show up to 42% of brachial plexus injuries occur without documented shoulder dystocia. This highlights the fact that not all injuries reflect mismanagement of a dystocia at birth and can often occur without any prior known risk factors.
- Fractures - The clavicle (collarbone) or humerus (upper arm) is often damaged during difficult deliveries, like when the baby's shoulder gets stuck in the birth canal or is forcefully pulled out via forceps or vacuum extractors. Fractures are also one of the most common birth injuries.
- Hypoxia and birth asphyxia - Compression of the umbilical cord or chest can reduce oxygen. This may lead to HIE or acute neonatal encephalopathy.
- Cerebral palsy and developmental delays - In severe or prolonged cases, reduced oxygen may cause permanent brain injury and lead to developmental disorders such as cerebral palsy.
Risks for the Mother
- Heavy bleeding (postpartum hemorrhage)
- Severe perineal or cervical tears (including third- and fourth-degree tears)
- Uterine rupture (rare but serious)
- Bladder or rectal injuries
- Pubic symphysis pain
How Is a Baby Monitored and Treated After Shoulder Dystocia?
Since shoulder dystocia is difficult to predict, doctors and medical staff must be able to spot the signs during labor and recognize signs of injuries after birth. The healthcare team will carefully evaluate your baby for any potential injuries or signs of oxygen deprivation. This diagnosis may include:
- A detailed newborn physical and neurological exam
- Checking arm movement, reflexes, and symmetry for possible brachial plexus injury
- Palpating the clavicles and upper arms for fractures
- Monitoring breathing, color, muscle tone, and feeding
- Blood tests (blood gases, lactate) if there is concern for asphyxia
- NICU admission and continuous monitoring for babies who appear unstable or show signs of HIE
Depending on the condition or severity of injury, your baby may be referred early to:
- Pediatric neurology (for seizures or suspected HIE)
- Physical and occupational therapy (for brachial plexus injury or Erb's palsy)
- Orthopedics (for fractures or joint concerns)
Can Shoulder Dystocia Be Prevented?
Experts agree that shoulder dystocia is mostly unpredictable and oftentimes unpreventable. There are some ways that providers can reduce the risks in certain situations, including:
- Closely monitoring women with diabetes or suspected macrosomia.
- Discussing planned cesarean birth (C-section) in very high-risk situations such as extreme fetal size with diabetes, very narrow pelvis, or prior severe shoulder dystocia with permanent injury.
- Using standardized skills training and simulation so that all medical staff know how to correctly and rapidly respond when shoulder dystocia occurs.
Delivery Maneuvers to Prevent Shoulder Dystocia
When shoulder dystocia happens, the delivery team follows specific maneuvers to free the baby's shoulder without pulling hard on the head or neck. These techniques widen the birth canal, rotate the baby's shoulders, and reduce pressure on the brachial plexus nerves that can lead to Erb's palsy.
McRoberts Maneuver: The McRoberts maneuver is often the first step when doctors recognize shoulder dystocia.
- The mother's legs are brought up and flexed tightly toward her abdomen.
- This position tilts the pelvis, flattens the lower spine, and increases the space for the baby's shoulder to pass through.
- It is simple and quick, and can resolve many cases without needing more invasive maneuvers.
Suprapubic Pressure: Suprapubic pressure is typically used together with the McRoberts maneuver.
- A provider presses firmly just above the mother's pubic bone (not on the baby's head) to help push the stuck shoulder forward and under the pubic bone.
- The pressure is directed downward and slightly sideways to rotate the shoulder, which can free the shoulder without excessive traction on the baby's neck.
Internal Rotational Maneuvers (Rubin & Woods "Corkscrew"): If McRoberts and suprapubic pressure do not work, the provider may perform internal maneuvers inside the birth canal, such as:
- Rubin Maneuver: The doctor reaches inside and applies a gentle amount of pressure to the back of the baby's front shoulder to rotate them into a narrower position. This helps the baby to slip under the pelvic bone with more ease.
- Woods Corkscrew Maneuver: This maneuver applies pressure to the back of the baby's rear shoulder and "corkscrews" the shoulders into a better angle. This maneuver rotates and releases the shoulders instead of pulling straight down on the head.
Delivery of the Posterior Arm: In some cases, the safest option involves bringing the baby's rear (posterior arm) out first.
- The provider reaches in and grabs the baby's forearm and sweeps it across the chest and out of the birth canal.
- Once that arm is delivered, the baby's shoulder width essentially shrinks, which gives more room for the front shoulder to pass.
Gaskin All-Fours Maneuver: The Gaskin maneuver involves changing the mother's position to hand-and-knees (all fours).
- Repositioning onto the hands and knees changes the shape of the pelvis and can help free the impacted shoulder.
- Gravity and pelvic movement may reduce the pressure on the baby's shoulder and allow delivery with much less traction.
- This technique is mainly used when the mother has enough mobility and pain control to safely change positions.
Episiotomy (Making More Space for Maneuvers): An episiotomy is a surgical cut in the perineum (the tissue between the vagina and anus).
- On its own, an episiotomy does not fix shoulder dystocia since the shoulder is stuck behind the pubic bone, not the vaginal opening.
- However, it gives the provider more room to perform internal maneuvers (such as Rubin, Woods, or delivery of the posterior arm) safely and quickly.
Last Resort Maneuvers (In Very Rare Situations): In extremely rare and life-threatening cases where standard maneuvers fail, these last resort options can help.
- Zavanelli Maneuver: Gently pushing the baby's head back into the birth canal and then performing an emergency C-section.
- Symphysiotomy (almost never used in high-resource situations): Cutting the cartilage of the pubic symphysis to widen the pelvic opening.
Note: The Zavanelli maneuver and symphysiotomies are rarely performed in modern obstetric practice and are last resort options for situations where the baby's life is in immediate danger and all of the other maneuvers and techniques have failed.
Doctors and nurses are trained to move quickly, call for extra help, and work as a team. Families usually see a lot happening all at once, but behind the scenes there is a structured protocol being followed.
What Is the Prognosis for Shoulder Dystocia?
Prognosis can vary from near-full recovery to lifelong disability. However, most babies affected by shoulder dystocia recover very well. According to Cleveland Clinic, 50% of babies function completely by 3 months, and about 82% by 18 months after shoulder dystocia.
In rarer, severe cases, children may live with:
- Persistent arm weakness or limited range of motion (Erb's palsy)
- Asymmetry in arm length or muscle mass
- Long-term effects of HIE, such as cerebral palsy, epilepsy, or developmental delays
The good news is that more than 90% of brachial plexus injuries improve within 6 to 12 months, with fewer than 10% resulting in permanent disabilities.
Shoulder Dystocia FAQs
Written and Medically Reviewed by:
Cerebral Palsy Hub Team
Cerebral Palsy Hub was founded to help support children and their families with cerebral palsy and to create a safe space for those affected. We strive to provide the most accurate, up-to-date information, and tools to help give your child the life they deserve.
Last Updated: December 13, 2025
