The brachial plexus is a group of nerves around shoulder. A loss of movement or weakness of the arm may occur if these nerves are damaged. This injury is called neonatal brachial plexus palsy (NBPP)
The nerves of the brachial plexus can be affected during a difficult delivery. Injury may be caused by:
- The infant's head and neck pulling toward the side as the shoulders pass through the birth canal
- Stretching of the infant's shoulders during a head-first delivery
- Pressure on the baby's raised arms during a breech (feet-first) delivery
There are different forms of NBPP. The type depends on the amount of arm paralysis:
- Brachial plexus palsy most often affects only the upper arm. It is also called Duchenne-Erb or Erb-Duchenne paralysis.
- Klumpke paralysis affects the lower arm and hand and is much less common.
The following factors increase the risk of NBPP:
- Breech delivery
- Larger-than-average newborn (such as an infant of a diabetic mother)
- Difficulty delivering the baby's shoulder after the head has already come out (called shoulder dystocia)
NBPP is less common now that delivery techniques have improved. Cesarean delivery is used more often when there are concerns about a difficult delivery. Although a C-section reduces the risk of injury, it does not prevent it. A C-section procedure also carries other risks.
NBPP may be confused with a condition called pseudoparalysis. This is when the infant has a fracture and is not moving the arm because of pain, but there is no nerve damage.
Symptoms can be seen right away or soon after birth. They may include:
- No movement in the newborn's upper or lower arm or hand
- Absent Moro reflex on the affected side
- Arm flexed (bent) at elbow and held against body
- Decreased grip on the affected side
Exams and Tests
A physical exam most often shows that the infant is not moving the upper or lower arm or hand. The affected arm may flop when the infant is rolled from side to side.
The Moro reflex is absent on the side with the brachial plexus palsy.
The health care provider will examine the collarbone to look for a fracture. The infant may need to have an x-ray taken of the collarbone.
Gentle massage of the arm and range-of-motion exercises are recommended for mild cases. The infant may need to be seen by specialists if the damage is severe or the condition does not improve in the first few weeks.
Surgery may be considered if some strength has not returned to the affected muscles by the time the baby is 3 to 9 months old.
Most babies will fully recover within 3 to 9 months. Those who do not recover during this time have a poor outlook. In these cases, there may be a separation of the nerve root from the spinal cord (avulsion).
It is not clear whether surgery to fix the nerve problem can help. Nerve grafts and nerve transfers are sometimes tried in specialized centers with expertise in managing NBPP.
In cases of pseudoparalysis, the child will begin to use the affected arm as the fracture heals. Fractures in infants heal quickly and easily in most cases.
- Abnormal muscle contractions (contractures) or tightening of the muscles. These may be permanent.
- Permanent, partial, or total loss of function of the affected nerves, causing paralysis of the arm or arm weakness
When to Contact a Medical Professional
Call your provider if your newborn shows a lack of movement of either arm.
Taking measures to avoid a difficult delivery, whenever possible, reduces the risk of brachial plexus palsy in newborn babies.
Klumpke paralysis; Erb-Duchenne paralysis; Erb's palsy; Brachial palsy; Obstetrical brachial plexus palsy; Birth-related brachial plexus palsy; Neonatal brachial plexus palsy; NBPP
Executive summary: Neonatal brachial plexus palsy. Report of the American College of Obstetricians and Gynecologists' Task Force on Neonatal Brachial Plexus Palsy. Obstet Gynecol. 2014 Apr;123(4):902-904. PMID: 24785634 www.ncbi.nlm.nih.gov/pubmed/24785634.
Liu RW, Thompson GH. Musculoskeletal disorders in neonates. In: Martin RJ, Fanaroff AA, Walsh MC, eds. Fanaroff and Martin's Neonatal-Perinatal Medicine. 10th ed. Philadelphia, PA: Elsevier Mosby; 2015:chap 105.
Update Date 11/3/2015
Updated by: Kimberly G Lee, MD, MSc, IBCLC, Associate Professor of Pediatrics, Division of Neonatology, Medical University of South Carolina, Charleston, SC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.