When a newborn’s arm lies still after a difficult delivery, families are left with urgent questions and very few clear answers. This guide explains what brachial plexus injury at birth actually is — medically, practically, and legally.
By Eleanor Davis · Medical-Legal Editorial Contributor
Reviewed by the Editorial Review Team · Updated May 2026
Editorial Disclaimer: This article is for general informational purposes only. It does not constitute medical advice, legal advice, or a guarantee of any diagnosis, legal claim, or compensation outcome. Always consult a qualified physician for medical decisions and a licensed attorney for legal questions. Circumstances vary significantly by individual case, state law, and jurisdiction.
How We Reviewed This Article
This guide was prepared using publicly available medical sources, including peer-reviewed literature on neonatal brachial plexus palsy, clinical references from major medical institutions, and general legal guidance from bar association resources. All factual claims were reviewed against cited sources. Statistics are presented with appropriate context and sourcing. No medical credentials, legal outcomes, settlement values, or expert names were invented or implied.
For most families, the delivery room ends in relief. But when a newborn arrives with one arm that won’t move — a small limb hanging still while everything else is wriggling, crying, alive — that relief turns into something else entirely. Questions begin almost immediately. What happened? Was something done wrong? Will my child’s arm ever work normally?
Those questions deserve clear, honest answers. This guide attempts to provide them.
What Is a Brachial Plexus Injury at Birth?
The brachial plexus is a network of nerves that originates from the lower cervical and upper thoracic spine — specifically the nerve roots labeled C5 through T1. These nerves travel from the neck down through the shoulder, arm, and into the hand, controlling movement and sensation along the entire upper limb. Shoulder rotation, elbow flexion, wrist extension, grip — all of it depends on this network functioning properly.
A brachial plexus injury at birth occurs when those nerves are damaged during delivery. The mechanism is usually mechanical: the nerve roots are stretched, compressed, or torn as the baby passes through the birth canal, particularly during difficult deliveries involving shoulder impaction, instrumental assistance, or unusual positioning. According to StatPearls via the National Library of Medicine, injury severity ranges from temporary bruising with full expected recovery to complete nerve root avulsion — where the nerve tears entirely from the spinal cord.
The most common presentation is Erb’s palsy, an upper trunk injury involving C5 and C6, which primarily affects shoulder and elbow function. The American Academy of Orthopaedic Surgeons describes it as one of the more recognizable birth injuries, though its full spectrum — from mild, transient weakness to lasting paralysis — varies considerably depending on injury type and severity.
Why a Baby’s Arm May Not Move After Delivery
The first sign is usually visible within minutes of birth. The affected arm hangs still at the baby’s side, or rests in an unusual position — internally rotated at the shoulder, elbow slightly flexed, wrist and fingers curled. This posture is often described as a “waiter’s tip” presentation and is a hallmark of upper trunk Erb’s palsy.
Clinicians in the delivery room typically assess asymmetric Moro reflex — the startle response in which a newborn normally extends both arms symmetrically. When one arm fails to respond, it is a meaningful clinical sign. Reduced spontaneous movement of the shoulder and elbow on the affected side, along with diminished grip or arm tone, will also be noted during the initial newborn exam.
Some infants retain meaningful finger movement even with significant upper arm weakness. This reflects the anatomy of which roots were affected: the upper brachial plexus nerves (C5–C6) govern the shoulder and elbow, while the lower roots (C8–T1) control fine hand movement. Preserved finger function in an otherwise still arm is not reassurance that the injury is minor.
Any asymmetric arm movement or absent Moro response at birth warrants prompt clinical evaluation, ideally involving a pediatric neurologist or orthopedic surgeon experienced in brachial plexus birth injuries.
Common Causes and Risk Factors
Shoulder dystocia — when the baby’s anterior shoulder becomes impacted behind the maternal pubic bone after the head has been delivered — is the single most direct precipitating event. The delivery team must act quickly to free the impacted shoulder, and the forces involved, whether applied or inherent to the delivery itself, can stretch the brachial plexus beyond its tolerance.
The Canadian Paediatric Society identifies the following as established risk factors for neonatal brachial plexus palsy:
- Fetal macrosomia (large birth weight, often defined as above 4,000–4,500 g)
- Maternal diabetes, gestational or pre-existing, which increases macrosomia risk
- Prolonged or arrested second-stage labor
- Instrumental vaginal delivery using forceps or vacuum
- Breech presentation, particularly with extended arms
- Prior delivery complicated by shoulder dystocia
- Maternal obesity or short stature
Cesarean section substantially reduces — but does not eliminate — the risk. Cases of brachial plexus injury have been documented following C-sections, and some research suggests that a small proportion of injuries may originate in utero, before labor begins. The clinical significance of in-utero injury as a proportion of all cases remains a subject of ongoing expert discussion.
Not every brachial plexus birth injury is the result of preventable error. Some occur in the context of an unexpected shoulder dystocia that develops despite careful obstetric management. That distinction matters — both medically and legally.
~1.7
cases per 1,000 live births (pooled global estimate)
Source: Developmental Medicine & Child Neurology systematic review
3–27%
of affected infants may experience some permanent deficit
Source: HSS Health Library; range reflects variation in injury severity and study methodology
C5–C6
most commonly affected nerve roots (Erb’s palsy pattern)
Source: AAOS; StatPearls / NLM
These are population-level estimates. Figures vary across studies based on population, injury definition, follow-up duration, and methodology. They do not predict outcomes for any individual child.
Types of Brachial Plexus Nerve Injuries
Not all brachial plexus injuries are the same. The degree of structural damage to the nerve determines both the severity of initial paralysis and the realistic window for recovery. According to StatPearls, injuries are generally classified along the following spectrum:
- Neurapraxia — nerve bruising without structural disruption; the most common and typically most recoverable form
- Axonotmesis — partial disruption of nerve fibers within an intact sheath; recovery is possible but slower
- Neurotmesis — complete severance of the nerve; recovery requires surgical intervention and is less predictable
- Avulsion — the nerve root is torn from the spinal cord; spontaneous recovery is not possible and surgical options are limited
The majority of birth-related brachial plexus injuries are upper trunk injuries (C5–C6), affecting shoulder elevation, elbow flexion, and forearm rotation. More severe total plexus injuries involve all five roots and can leave the entire arm without voluntary movement or sensation. These are less common but carry a substantially different prognosis.
Diagnosis and Early Evaluation
Initial diagnosis is clinical — based on the newborn physical exam and the asymmetric Moro reflex. A more thorough neurologic and orthopedic assessment follows in the days after birth, mapping the specific pattern of weakness and identifying associated injuries such as clavicle fractures or cervical spine abnormalities, which can occur in the same delivery complications.
For infants with more severe or uncertain presentations, advanced imaging provides additional information. MRI of the brachial plexus or cervical spine can identify root avulsions and help guide surgical planning. CT myelography remains an option when MRI is not feasible. Electrodiagnostic studies — including electromyography (EMG) and nerve conduction velocity testing — are typically performed around three to four months of age to assess reinnervation and inform decisions about surgical intervention.
Early referral to a brachial plexus specialty program is strongly recommended when weakness persists beyond the first weeks of life. The window for nerve surgery, if needed, is generally between three and nine months of age.
Treatment and Recovery
Early physical therapy is the foundation of initial management. Beginning within the first weeks of life, gentle range-of-motion exercises help preserve joint mobility, prevent contracture, and maintain the affected limb while the nervous system either heals or is assessed for surgical candidacy. Occupational therapy becomes increasingly important as children develop fine motor skills, self-care abilities, and daily function.
The three-month checkpoint is widely referenced in clinical literature: infants who show no meaningful bicep function at around three months are generally considered candidates for nerve surgery evaluation. This is not a hard deadline, and individual circumstances vary — but it reflects the documented window during which nerve grafting and nerve transfer procedures tend to produce the most meaningful functional gains.
Surgical options, when indicated, may include:
- Nerve grafting — using a section of sensory nerve to bridge a torn brachial plexus segment
- Nerve transfer — redirecting a functioning nerve to restore movement in a specific muscle group
- Tendon transfers — repositioning tendons to compensate for function that nerves have not recovered
- Botulinum toxin (Botox) injections to manage muscle imbalance in some presentations
According to the Cleveland Clinic, many children with upper trunk injuries recover significant function — some fully — especially with early, consistent therapy. Children with severe or total plexus injuries, or those with avulsion components, face a substantially more difficult path. Prognosis depends on injury type and severity and cannot be generalized from population statistics.
“Recovery is possible for many children — but the severity of the nerve injury, the timing of evaluation, and the consistency of early therapy each play a significant role in outcomes. No single statistic applies to any individual child.”
When Brachial Plexus Injury May Involve Medical Negligence
This section deserves a careful, honest answer: not every brachial plexus birth injury is the result of medical negligence.
Some injuries occur despite appropriate clinical management. Shoulder dystocia can develop unexpectedly, and the forces required to cause nerve damage can, in some documented cases, be generated by the normal expulsive forces of labor without additional clinician-applied traction. Published research has noted brachial plexus injuries following cesarean deliveries and in cases where injury appears to have occurred before delivery began — though the frequency and clinical significance of these findings remain areas of ongoing expert discussion.
That said, the circumstances surrounding some deliveries raise legitimate questions about whether the standard of care was met. Clinical and legal experts reviewing brachial plexus cases often examine whether:
- Shoulder dystocia was recognized promptly and managed with established maneuvers
- Excessive lateral traction was applied to the baby’s head or neck
- Fundal pressure was used during shoulder impaction, which may worsen the obstruction
- Known macrosomia or diabetes risk went unaddressed in the delivery plan
- Forceps or vacuum were applied appropriately and under appropriate indications
- Cesarean delivery was considered when risk factors were present and labor was not progressing
- Documentation accurately reflects the sequence of events, timing, and maneuvers used
Establishing negligence requires demonstrating both a breach of the standard of care and that the breach caused the specific injury. That causation analysis requires qualified expert medical review. Neither conclusion can be reached from a parent’s perspective without access to the full medical record and professional evaluation.
What Medical Records Matter Most
If families want to understand what happened during delivery — for their own clarity or as part of a potential legal review — gathering complete medical documentation is the essential first step.
- Prenatal care records, including growth scans and fetal weight estimates
- Gestational diabetes screening and management records
- Labor and delivery nursing notes
- Fetal monitoring strips (CTG / EFM records)
- Delivery or operative notes documenting the sequence of events
- Documentation of shoulder dystocia, if noted, and maneuvers performed
- Forceps or vacuum application records and clinical indications
- Records of any decision to proceed with or delay cesarean delivery
- Newborn physical exam findings from the delivery room and nursery
- Neurology and orthopedic consultation reports
- Physical and occupational therapy records
- Imaging reports (MRI, CT myelography) and electrodiagnostic results
- Surgical records, if applicable
In most U.S. jurisdictions, patients and their legal representatives have the right to request complete medical records. Hospitals are generally required to provide them within a defined timeframe. Requesting records promptly is advisable.
What Compensation May Cover
In cases where a birth injury claim is pursued and succeeds, compensation may address a range of documented losses and needs. These vary significantly depending on injury severity, jurisdiction, and the specific facts of each case. Commonly cited categories in birth injury litigation include:
- Physical and occupational therapy costs, past and projected
- Nerve surgery, tendon transfer, and related surgical procedures
- Specialist consultations and ongoing monitoring
- Adaptive equipment or assistive devices
- Pain and suffering, and effects on quality of life
- Long-term functional limitations and educational or vocational impact
- In severe cases, loss of future earning capacity
No specific settlement amounts or outcomes are represented here. Compensation in birth injury cases varies based on legal theory, expert testimony, jurisdiction, insurance coverage, and individual case facts. There is no guarantee of recovery.
When to Speak With a Birth Injury Lawyer
Families do not need to have concluded that negligence occurred before consulting an attorney. The purpose of an initial legal consultation is to have qualified professionals review the medical record — with the help of expert consultants — and help families understand whether the circumstances of the delivery warrant further investigation.
Many birth injury attorneys offer initial consultations at no cost, though policies vary by firm and jurisdiction. What matters in those early conversations is usually access to the medical record, which is why gathering documentation early is valuable regardless of whether a legal claim is ultimately pursued.
Statutes of limitations — the legal deadlines for filing a birth injury claim — vary by state and by the type of claim. In some jurisdictions, special rules apply to minors, extending the available time. Because these deadlines vary and can be consequential, consulting an attorney sooner rather than later is generally advisable. The American Bar Association’s legal help resources can assist families in locating qualified attorneys in their area.
Key Takeaways
- Brachial plexus injury at birth occurs when nerves running from the lower neck to the arm are damaged during delivery, causing weakness or paralysis of the affected limb
- The most common form — Erb’s palsy — affects the upper trunk (C5–C6) and primarily limits shoulder and elbow movement, while preserving some finger function in many cases
- Risk factors include shoulder dystocia, fetal macrosomia, maternal diabetes, instrumental delivery, prolonged labor, and prior shoulder dystocia — though no risk factor guarantees injury will occur
- Injury severity ranges from temporary nerve bruising (neurapraxia) to complete avulsion from the spinal cord; prognosis varies accordingly and cannot be generalized from population data
- Early physical therapy and specialist evaluation are critical; the three-month window is a clinical checkpoint, not an absolute deadline, for nerve surgery candidacy
- Not every brachial plexus birth injury is caused by medical negligence; some occur despite appropriate care, and establishing liability requires expert medical-legal review
- Families who have concerns should gather complete medical records early and, if warranted, consult a qualified birth injury attorney
A Final Note for Families
A newborn with a still, unmoving arm is not an abstraction. It is a child who will grow, adapt, and face real challenges — and a family navigating fear, grief, and uncertainty in one of the most vulnerable moments of their lives.
The medical system can feel opaque. The legal system can feel adversarial. Neither process is easy. But understanding what happened — medically and factually — is not just a legal question. For many families, it is the beginning of being able to plan, advocate, and provide what their child needs.
That process starts with honest clinical evaluation, complete documentation, and, when questions remain, professional guidance from people with the expertise to actually assess the record.
If your baby’s arm was weak or paralyzed after delivery, the next step is not to assume malpractice occurred. It is to have the medical records, diagnosis, and delivery timeline reviewed by qualified professionals — medical and legal — who can evaluate what actually happened and what options, if any, may be available. Many birth injury attorneys offer initial consultations at no cost, though policies vary by firm and jurisdiction. Deadlines to file a claim vary by state, so early inquiry is advisable.
Recommended External Sources
- American Academy of Orthopaedic Surgeons — Erb’s Palsy / Brachial Plexus Birth Palsy
- MedlinePlus (NIH) — Brachial Plexus Injuries
- StatPearls / National Library of Medicine — Brachial Plexus Injuries
- Canadian Paediatric Society — Neonatal Brachial Plexus Palsy
- Cleveland Clinic — Erb’s Palsy
- Hospital for Special Surgery — Brachial Plexus Birth Injuries
- Developmental Medicine & Child Neurology — Global Incidence of Neonatal Brachial Plexus Palsy
- American Bar Association — Free Legal Help Resources
This article is for informational purposes only. It does not constitute legal or medical advice and does not create an attorney-client relationship. Laws vary by state and jurisdiction. Consult a qualified attorney for guidance specific to your situation.
Eleanor Davis
