Shoulder Dystocia

What Is Shoulder Dystocia?

Doctor Checking Baby's ArmShoulder dystocia is an obstetrical emergency during childbirth that occurs when a baby's anterior shoulder becomes stuck behind the mother's pelvic bone preventing the baby from continuing through the birth canal. Shoulder dystocia is a comparatively common type of obstetrical complication.

Approximately 2% of vaginal deliveries in the U.S. reported some level of shoulder dystocia. Of course, the true incidence of shoulder dystocia is somewhat difficult to establish because there is a wide variation in diagnostic and reporting criteria among hospitals. Not surprisingly, shoulder dystocia is more common in male babies and full-term babies because both of tend to be comparatively larger.

Shoulder dystocia is caused by many interrelated factors including the size of the baby (particularly the width of the baby's shoulders); the size of the mother and the birth canal, and the angle of the baby in the birth canal.

How Should Shoulder Dystocia Be Handled?

When shoulder dystocia occurs it immediately threatens the safety of both mother and baby. It is treated as an obstetrical emergency. If shoulder dystocia is not properly identified and overcome, a baby can potentially die or suffer serious brain damage from oxygen deprivation. As a result, OB/GYNs have a very limited window of time to act in response to shoulder dystocia. Unfortunately, the response to shoulder dystocia by doctors can often be just as risky for the baby.

There are a variety of well-known manipulative techniques and obstetrical procedures that obstetricians can employ to overcome shoulder dystocia. The primary manipulative techniques commonly used by OB/GYNs when infant shoulder dystocia occurs include the Rubin, Jacquemier, and Woods techniques. The so-called McRoberts maneuver and the use of suprapubic pressure are other widely used procedures for handling shoulder dystocia.

When shoulder dystocia is first encountered during delivery, the doctor's initial step is to accurately determine the actual orientation of the baby's anterior shoulder (i.e., angle, depth, etc.). Accurate assessment of shoulder position and orientation is critical because the specific orientation will dictate what obstetrical techniques and/or maneuvers will be most effective in dislodging the shoulder. Certain techniques are designed for use with specific orientations.

After the orientation of the shoulder has been fully assessed the doctor must decide on a strategy for responding to the situation, including which of the various techniques to employ. This is where things can get very tricky. It is very important to overcome the dystocia and deliver the baby as quickly as possible.

At the same time, however, excessive haste, overly aggressive manipulation, hyperflexion of the baby's neck, or the use of excessive force will easily cause injury to the baby. A very high level of skill is required to overcome the baby's shoulder dystocia without injuring the mother or child.

The problem is that shoulder dystocia simply does not occur often enough for most doctors to develop expertise or test out various methods. As a result, many OB/GYNs lack confidence in their skills which often causes them to panic and make rushed decisions.

Shoulder Dystocia and Birth Injuries

When shoulder dystocia occurs the risk of a birth injury automatically skyrockets. Anxiety and a lack of experience caused many doctors to employ excessive force in response to shoulder dystocia which routinely causes injury to the baby. Physical trauma injuries to the newborn such as broken bones or facial damage are common. Other common birth injuries resulting from shoulder dystocia include:

  • Erb's Palsy: birth injury caused by damage to the brachial plexus nerves in the shoulder/neck area. The brachial plexus nerves connect the brain to the arms and hands. When these nerves are damaged during childbirth it can result in Erb's palsy which is characterized by paralysis in the arm/hand.
  • Klumpke's Palsy: nerve damage injury during childbirth that also results in paralysis of the newborn's hands or lower arms caused by injury to a nerve channel in the lower spine.
  • Cerebral Palsy: mismanagement of shoulder dystocia can potentially result in a temporary loss of oxygen to the infant's brain. This can happen several ways including prolonged pressure, compression of the umbilical cord, and excessive trauma. Oxygen deprivation during childbirth can result in cerebral palsy - a condition that impairs the brain's ability to control the movement of the body.
FAQs: Shoulder Dystocia

Below are answers to some of the most commonly asked questions and concerns about shoulder dystocia (shoulder stuck at birth). So some of this is a retread from above.  But some parents prefer to digest information in this format.

How often does a baby’s shoulder get stuck at birth?

Shoulder dystocia (baby’s shoulder gets stuck during birth) occurs in roughly 3% of vaginal deliveries in the U.S. and 5% of vaginal deliveries worldwide. Shoulder dystocia is much more common in full-term, male babies with larger birth weights.

Why does baby shoulder dystocia happen?

Shoulder dystocia happens when the baby’s shoulder gets stuck behind the mother’s pelvic bone during vaginal childbirth. Shoulder dystocia is usually the result of various factors such as the size and width of the baby, the size of the mother’s pelvis, and the angle of the baby during delivery.

What is a shoulder dystocia injury?

Shoulder dystocia birth injuries occur when the doctor or midwife uses excessive force or pressure to dislodge the baby’s stuck shoulder. Excessive force or the use of instruments such as forceps or vacuum extractors can result in nerve damage and conditions such as Erb’s palsy. Mismanaged shoulder dystocia can also result in oxygen deprivation causing brain damage and cerebral palsy.

Can shoulder dystocia cause brain damage?

When shoulder dystocia occurs during childbirth it can cause compression of the umbilical cord and oxygen deprivation. Permanent brain damage will occur if the baby is deprived of sufficient oxygen for a prolonged period.

Shoulder Dystocia - Studies & Research

Poujade, Olivier, et al. "Prevention of shoulder dystocia: A randomized controlled trial to evaluate an obstetric maneuver." European Journal of Obstetrics & Gynecology and Reproductive Biology 227 (2018): 52-59. (This study evaluated whether the push back maneuver could reduce the shoulder dystocia risk. The researchers found that it reduced shoulder dystocia rates compared to standard vaginal deliveries.)  

 Sancetta, Ronald, Hiba Khanzada, and Ricardo Leante. "Shoulder shrug maneuver to facilitate delivery during shoulder dystocia." Obstetrics and Gynecology 133.6 (2019): 1178. (This study looked at whether the shoulder shrug maneuver could resolve shoulder dystocia. The researchers examined three cases involving this technique. They concluded that successful shoulder shrug maneuvers decreased neonate morbidity. The researchers advised healthcare providers to consider this technique to address shoulder dystocia.)  

 Santos, Palmira, et al. "Population-based risk factors for shoulder dystocia." Journal of Obstetric, Gynecologic & Neonatal Nursing 47.1 (2018): 32-42. (This study re-examined shoulder dystocia risk factors. Based on their data, the researchers found that epidural anesthesia and gestational diabetes treated with insulin were significant risk factors. Other risk factors included being Black or Latino, Medicaid-insured or uninsured, chronically diabetic, and 41 weeks pregnant or later.) 

 Tsur, A., et al. "Development and validation of a machinelearning model for prediction of shoulder dystocia." Ultrasound in Obstetrics & Gynecology 56.4 (2020): 588-596. (Researchers developed a machine-learning model that attempted to predict shoulder dystocia. They found that the model was better at predicting shoulder dystocia than estimated fetal weight, even with the inclusion of gestational diabetes.)    

 Zhang, C., et al. "Maternal prepregnancy obesity and the risk of shoulder dystocia: a metaanalysis." BJOG: An International Journal of Obstetrics & Gynaecology 125.4 (2018): 407-413. (This meta-analysis looked at the association between maternal obesity and shoulder dystocia. The researchers concluded that maternal obesity increased the shoulder dystocia risk.)