Difficulty delivering the baby's shoulder after the head has already come out (called shoulder dystocia)
Brachial plexus injury 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, and the procedure carries other risks.
Brachial plexus injury 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
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 or nerve injury.
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 evaluated 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 - 6 months old.
Most babies will fully recover within 3 to 6 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 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 health care 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 injury in newborn babies.
Pham CB, Kratz JR, Jelin AC, Gelfand AA. Child neurology: brachial plexus birth injury: what every neurologist needs to know. Neurology. 2011;77:695-697. PMID: 21844527 www.ncbi.nlm.nih.gov/pubmed/21844527.
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.