Brachial Plexus Birth Injury: Causes, Symptoms & Treatment

What Is Brachial Plexus Birth Injury?

Brachial plexus birth injury is damage to the network of nerves (brachial plexus) that control movement and sensation in the shoulder, arm, and hand, occurring during the birth process. The injury ranges from mild nerve stretching that heals spontaneously to severe nerve tears or avulsions requiring surgery.

The brachial plexus is a complex network of nerves that originate from the spinal cord in the neck (cervical vertebrae C5-T1) and travel down through the shoulder to control all movement and sensation in the arm and hand. When these nerves are damaged during birth, the baby may have difficulty moving the affected arm, ranging from minor weakness to complete paralysis depending on the severity of the injury.

Brachial plexus birth injury is also known by several other names in medical literature, including obstetric brachial plexus palsy (OBPP), Erb's palsy (when upper nerves are affected), and Klumpke's palsy (when lower nerves are affected). Understanding the specific type and location of nerve damage is important because it determines the expected recovery pattern and treatment approach.

While brachial plexus injury can be frightening for parents to witness, it's important to understand that the vast majority of cases resolve with minimal or no long-term effects. The nerves have remarkable ability to heal, particularly when the injury involves stretching rather than tearing. Modern medical care, including early physical therapy and, when necessary, microsurgical techniques, has significantly improved outcomes even for more severe injuries.

Types of Nerve Damage

The severity of brachial plexus birth injury depends on the type of damage to the nerves. Understanding these different injury types helps predict recovery and guide treatment decisions. There are three main categories of nerve injury that occur in newborns:

• Neurapraxia (nerve stretching): The mildest form where nerves are stretched but not torn. This is the most common type and typically heals completely within 2-3 months without any intervention other than physical therapy.
• Rupture (nerve tear): The nerve is torn within its sheath but remains connected to the spinal cord. This requires more extensive treatment and may need surgical repair. Recovery is possible but may be incomplete.
• Avulsion (nerve root separation): The most severe injury where the nerve root is pulled out of the spinal cord. This type cannot heal on its own and requires surgical nerve transfer procedures to restore any function.

In many cases, a combination of these injury types may be present, with some nerves stretched and others torn. Specialized imaging studies and clinical evaluation help medical teams assess the exact nature of the damage and plan appropriate treatment.

What Causes Brachial Plexus Injury in Newborns?

Brachial plexus birth injury typically occurs during complicated vaginal delivery when the baby's shoulder becomes stuck behind the mother's pubic bone (shoulder dystocia). The nerves can be stretched, torn, or pulled from the spinal cord when medical staff must urgently deliver the baby to prevent oxygen deprivation.

The most common cause of brachial plexus birth injury is shoulder dystocia, a delivery complication that occurs when the baby's head has been delivered but one or both shoulders become trapped behind the mother's pelvic bones. This situation requires urgent intervention because the umbilical cord may become compressed, putting the baby at risk for oxygen deprivation. When the delivery team works to free the trapped shoulder, the stretching force applied to the neck can damage the delicate nerves of the brachial plexus.

It's important for parents to understand that shoulder dystocia is often unpredictable and that medical staff must make rapid decisions to protect the baby's life. While the resulting nerve injury can be distressing, the alternative of prolonged entrapment could result in far more serious consequences including brain damage from oxygen deprivation.

The mechanism of injury involves lateral traction (pulling sideways) on the baby's neck during delivery. When the shoulder is stuck, and the head is being delivered, this creates tension on the brachial plexus nerves. The force required to deliver the baby can exceed the tensile strength of the nerves, causing stretching or tearing. In breech deliveries (feet-first), similar forces can occur when delivering the arms or head.

Risk Factors for Brachial Plexus Birth Injury

While brachial plexus injury cannot always be predicted or prevented, several factors increase the risk of this complication occurring during delivery:

Other contributing factors include breech presentation (feet-first delivery), instrumental deliveries using vacuum or forceps, previous delivery with shoulder dystocia, maternal obesity, and advanced maternal age. However, it's crucial to note that brachial plexus injury can also occur in deliveries with none of these risk factors, and many women with multiple risk factors deliver without complications.

What Are the Symptoms of Brachial Plexus Birth Injury?

The most obvious symptom of brachial plexus birth injury is a limp or paralyzed arm that the newborn cannot move normally. The affected arm may be held close to the body with the elbow straight, arm rotated inward, and wrist and fingers bent. Symptoms typically appear immediately after birth.

Brachial plexus injury is usually identified immediately after delivery or within the first few hours of life when medical staff perform the newborn examination. The hallmark sign is asymmetric arm movement – the baby moves one arm normally while the other arm remains limp or moves weakly. This is often noticed when the baby demonstrates the Moro reflex (startle reflex), which should cause both arms to extend symmetrically.

The specific symptoms depend on which nerves are affected and the severity of the injury. When the upper nerves (C5-C6) are damaged, a condition called Erb's palsy, the baby cannot lift the arm at the shoulder or bend the elbow, but hand and finger movement may be preserved. When lower nerves (C8-T1) are affected, called Klumpke's palsy, the hand and fingers are primarily affected while shoulder movement may be relatively normal. In severe cases involving all nerve roots, the entire arm may be paralyzed.

Signs to Look For

Parents and caregivers should be aware of the following signs that may indicate brachial plexus injury in a newborn:

• Limp or floppy arm: The affected arm hangs loosely at the side without active movement
• Characteristic arm position: Arm held close to body with elbow straight, forearm rotated inward ("waiter's tip" position)
• Bent wrist and fingers: The hand may be clenched or the wrist bent downward
• Asymmetric reflexes: The startle reflex (Moro) appears only on one side
• Lack of grasp reflex: The baby doesn't grip with the affected hand when palm is touched
• Decreased sensation: Reduced response to touch on the affected arm (though this is harder to assess)

Symptoms as the Child Grows

For children whose brachial plexus injury does not resolve completely within the first few months, certain symptoms may become more apparent as they grow and develop. These ongoing effects vary considerably depending on the severity of the initial injury and the nerves involved.

Children with residual effects may experience difficulty with specific movements such as lifting the arm above the head, rotating the forearm, or fully extending the elbow. The shoulder joint may develop stiffness (contracture) over time if range-of-motion exercises are not performed regularly. This happens because the muscles on one side of the joint may be weaker, allowing the opposing muscles to pull the joint into an abnormal position.

Another long-term consideration is that the affected arm and shoulder may grow somewhat smaller than the unaffected side. This occurs because reduced nerve stimulation affects muscle development and, to some extent, bone growth. While this size difference may be noticeable, it typically does not significantly impact the child's ability to use the arm functionally.

How Is Brachial Plexus Birth Injury Diagnosed?

Brachial plexus birth injury is initially diagnosed through physical examination immediately after birth, assessing arm movement, reflexes, and muscle tone. Babies who don't show improvement by 2 months should be referred to specialists for comprehensive evaluation including potential MRI imaging to visualize nerve damage and guide treatment planning.

The diagnosis of brachial plexus birth injury begins with careful observation and physical examination in the delivery room or nursery. Healthcare providers assess how the baby moves both arms, check reflexes including the Moro (startle) reflex and grasp reflex, and evaluate muscle tone in the affected limb. The position of the arm at rest and any response to stimulation provide important diagnostic clues.

In the initial days after birth, X-rays may be performed to rule out bone fractures that can cause similar symptoms. Fractures of the clavicle (collarbone) or humerus (upper arm bone) can occur during difficult deliveries and need to be identified because they affect treatment and recovery expectations.

For babies who continue to show signs of nerve injury beyond the first few weeks, referral to a specialized brachial plexus team is recommended. This multidisciplinary team typically includes pediatric neurologists, orthopedic surgeons with expertise in nerve reconstruction, and physical/occupational therapists. They conduct comprehensive evaluations to determine the extent of nerve damage and develop an appropriate treatment plan.

Diagnostic Tests and Imaging

Several diagnostic tools help medical teams assess the severity of brachial plexus injury and plan treatment:

• Physical examination: Regular assessments of arm movement, strength, and reflexes over time help track recovery progress
• MRI (Magnetic Resonance Imaging): High-resolution MRI can visualize the nerve roots and identify avulsion injuries where nerves have been pulled from the spinal cord. This is particularly important when surgery is being considered.
• CT myelography: In some cases, this imaging study provides detailed views of the nerve roots to identify avulsions
• Electromyography (EMG) and nerve conduction studies: These tests measure electrical activity in muscles and nerves, helping determine which specific nerves are affected and their degree of injury. However, these tests are less commonly used in very young infants.

Parents can contribute valuable information by observing their baby's arm movements at home and noting any changes. Keeping a written record or video documentation of movements can help specialists assess progress over time. Any improvements in movement, even small ones, are important to report as they indicate nerve recovery.

How Is Brachial Plexus Birth Injury Treated?

Treatment depends on injury severity. Most cases require only physical therapy to maintain joint flexibility while nerves heal naturally. Severe cases with no improvement by 3 months may need microsurgical nerve repair. Secondary surgeries for muscle/tendon transfers may be needed later to improve function in persistent cases.

The treatment approach for brachial plexus birth injury is tailored to the severity of the nerve damage and the child's response over time. For the majority of infants (80-90%), the injury involves nerve stretching that will heal spontaneously, and treatment focuses on supportive care to maintain joint flexibility and prevent complications during the healing period.

The fundamental principle of treatment is to preserve joint mobility and muscle flexibility while the nerves regenerate. Without regular movement, joints can become stiff (contractures), which can limit function even after nerve recovery is complete. This is why physical therapy is considered essential for all cases, regardless of severity.

For parents, receiving an early diagnosis of brachial plexus injury in their newborn can be overwhelming. It's important to understand that treatment is a gradual process, and many babies show significant improvement within the first months of life. The medical team will provide guidance and support throughout the recovery journey.

Physical Therapy and Home Exercises

Physical therapy is the cornerstone of treatment for brachial plexus birth injury. A physical therapist (or physiotherapist) specializing in pediatric conditions will teach parents gentle range-of-motion exercises to perform with their baby several times daily. These exercises are crucial for:

• Maintaining flexibility in all joints of the affected arm
• Preventing joint contractures (stiffness) from developing
• Stimulating muscle activity and preventing muscle wasting
• Encouraging normal movement patterns as nerves recover

The exercises involve gently moving each joint – shoulder, elbow, wrist, and fingers – through their full range of motion. Parents learn specific techniques to support the arm properly while performing movements. It's important that exercises are gentle and never forced; they should not cause pain or distress to the baby.

An occupational therapist may also be involved, providing guidance on positioning, play activities that encourage arm use, and adaptive techniques for daily care. They may recommend splints (orthoses) if certain joints are becoming stiff despite exercises. Splints help hold joints in functional positions, particularly during sleep.

Surgical Treatment

Surgery is considered when there is no significant improvement in arm function by approximately 3 months of age, suggesting that the nerves may be torn rather than just stretched. The optimal window for nerve reconstruction surgery is generally between 3-6 months of age, though the exact timing depends on the individual case.

Microsurgical nerve reconstruction is performed by specialized surgeons and may include:

• Nerve repair: Direct suturing of torn nerve ends when the gap is small enough
• Nerve grafting: Using a healthy nerve (usually taken from the baby's leg) to bridge gaps where nerves are torn
• Nerve transfer: Redirecting a less important working nerve to take over the function of a damaged critical nerve

The goal of primary nerve surgery is to restore nerve connections so that signals can travel from the brain to the arm muscles. Recovery after nerve surgery is gradual, occurring over months to years as new nerve fibers grow along the reconstructed pathways. Physical therapy continues throughout this period and is essential for maximizing functional outcomes.

Secondary Surgical Procedures

Some children may benefit from additional surgeries later in childhood to improve specific movements or correct joint problems. These secondary procedures are typically considered after nerve recovery has stabilized, usually after age 2-4 years:

• Muscle/tendon transfers: Moving functioning muscles to take over for those that did not recover
• Release of contractures: Surgically loosening tight muscles or tendons to improve joint mobility
• Bone procedures: Correcting shoulder or arm alignment if development has been affected

What Is the Long-Term Outlook for Brachial Plexus Birth Injury?

The prognosis for brachial plexus birth injury is generally positive, with 80-90% of affected babies achieving full or near-complete recovery. Children who recover within 2-3 months typically have no lasting effects. Those with persistent weakness can still lead active lives with appropriate therapy and support.

The long-term outlook for children with brachial plexus birth injury depends primarily on the type and severity of the initial nerve damage and how the nerves respond in the first few months of life. The natural healing ability of stretched nerves is remarkable, which is why the majority of cases resolve without surgical intervention.

For babies who show good biceps function (ability to bend the elbow against gravity) by 3 months of age, the prognosis is excellent, with most achieving complete or near-complete recovery. These children typically have no significant long-term limitations in arm function. However, even these children benefit from continued monitoring throughout early childhood to ensure optimal development.

For children with more severe injuries, the outlook depends on multiple factors including the specific nerves involved, whether surgical repair was possible, and the success of reconstructive procedures. Even when complete recovery is not achieved, many children develop effective compensatory strategies and adapt remarkably well to any residual limitations.

Living with Residual Effects

Children who have permanent effects from brachial plexus birth injury may face certain ongoing challenges, but these should not prevent them from leading full, active lives. Understanding what to expect helps families prepare and adapt:

• Arm size difference: The affected arm may be slightly shorter or smaller than the other arm. This is usually cosmetic rather than functional.
• Limited shoulder mobility: Difficulty raising the arm overhead or rotating the shoulder is common and may affect certain activities
• Muscle weakness: Ongoing weakness in specific muscle groups may require adaptations for certain tasks
• Coordination challenges: Some children have difficulty with fine motor skills or coordinating movements involving both hands

Most children with residual effects from brachial plexus injury participate fully in school, sports, and social activities. They may need to adapt how they perform certain tasks, and some activities may be more challenging, but children are remarkably adaptable. Schools can provide appropriate accommodations as needed, such as modified physical education activities or assistance with tasks requiring two-handed skills.

Can Brachial Plexus Birth Injury Be Prevented?

While not all cases can be prevented, risk can be reduced through proper prenatal care, management of gestational diabetes to prevent excessively large babies, and skilled delivery techniques when shoulder dystocia occurs. Women who have previously had a baby with brachial plexus injury are often recommended cesarean delivery for future pregnancies.

Prevention of brachial plexus birth injury focuses on identifying and managing risk factors when possible, and on appropriate management of shoulder dystocia when it occurs. However, it's important for parents to understand that shoulder dystocia can occur unexpectedly even in seemingly low-risk deliveries, and not all cases are preventable despite excellent care.

Prenatal care plays an important role in prevention by identifying factors that increase the risk of difficult delivery. Careful monitoring of fetal size through ultrasound measurements can identify babies that are growing exceptionally large (macrosomia). For women with gestational diabetes, good blood sugar control throughout pregnancy helps prevent excessive fetal growth.

When risk factors for shoulder dystocia are present, healthcare providers discuss delivery options with expectant mothers. In some cases, planned cesarean delivery may be recommended to avoid the potential complications of vaginal delivery. This decision involves weighing the risks and benefits for both mother and baby.

Prevention in Subsequent Pregnancies

For women who have previously had a baby with brachial plexus injury, the question of how to manage future pregnancies is important. The recurrence risk depends on several factors, and discussions with obstetric care providers should include:

• Review of the circumstances of the previous delivery
• Assessment of current pregnancy risk factors
• Estimated fetal size for the current pregnancy
• Discussion of delivery options including cesarean section

Many healthcare providers recommend cesarean delivery for subsequent pregnancies after a previous brachial plexus birth injury, particularly if shoulder dystocia was severe or if risk factors (such as large fetal size) are present in the current pregnancy. This recommendation balances the goal of preventing recurrence against the risks associated with cesarean surgery.

Where Can Families Find Support?

Families affected by brachial plexus birth injury can find support through specialized medical centers, parent support groups, and international organizations dedicated to this condition. Connecting with other families who have similar experiences can provide valuable emotional support and practical advice.

Receiving a diagnosis of brachial plexus birth injury in your newborn can be emotionally challenging. It's normal for parents to experience a range of feelings including shock, sadness, guilt, and anxiety about the future. Remember that this condition is not caused by anything the parents did or failed to do – it is a complication of the delivery process that can occur despite excellent medical care.

Building a support network is important for the well-being of both the child and the family. This network may include:

• Medical team: Pediatricians, specialists, physical therapists, and occupational therapists who understand your child's specific needs
• Family and friends: Loved ones who can provide practical help and emotional support
• Other affected families: Connecting with families who have been through similar experiences can be incredibly valuable
• Support organizations: Many countries have organizations dedicated to supporting families affected by brachial plexus injuries

Your child's medical team can provide referrals to local support resources and may know of family support groups in your area. Online communities can also be valuable, allowing you to connect with other families regardless of geographic location. These connections can provide practical tips, emotional support, and hope from seeing how other children have thrived despite their injuries.