The clavicle, commonly known as the collarbone, is the horizontal bone connecting the breastbone (sternum) to the shoulder. This bone is susceptible to fracture during the birthing process, especially as the baby passes through the narrow birth canal. A broken clavicle in a newborn is generally a straightforward injury with a favorable prognosis. This fracture is considered the most common bone injury sustained by a baby during delivery.
The Frequency of Neonatal Clavicle Fractures
The reported frequency of this injury varies across different studies, but the incidence is consistently low when measured against all live births. Recent data suggest that clavicle fractures occur in approximately 0.41% to 0.43% of all newborns. The overall range cited in medical literature spans from 0.2% to 4.5% of live births. This variation depends on the specific population studied and the diagnostic methods used.
Mechanisms of Injury During Childbirth
The fracture occurs due to mechanical stress placed on the bone as the baby navigates the mother’s bony pelvis. The most frequent mechanism involves the compression of the fetal shoulder against the maternal pubic bone during a vaginal delivery. This pressure causes the clavicle to bend and eventually break, usually near the middle of the bone.
Risk Factors
Certain factors increase the physical stress placed on the clavicle during delivery. Fetal macrosomia (a significantly large baby) is a risk factor because wider shoulders require more force to pass through the canal. Shoulder dystocia, where the baby’s shoulder becomes lodged behind the pubic bone, necessitates specific maneuvers that place excessive force on the collarbone. Assisted deliveries involving instruments like forceps or vacuum extractors are also associated with an elevated risk of this fracture.
Recognizing the Signs in a Newborn
Specific signs of a clavicle fracture may be noticed immediately after birth or within the first few days. A common indicator is reduced movement of the arm on the affected side, sometimes called pseudo-paralysis, as the baby avoids moving the limb due to pain. The newborn may also exhibit tenderness and cry when the injured side is lifted or moved, such as during dressing or diaper changes.
Upon examination, a healthcare provider may feel a grinding sensation, known as crepitus, or detect swelling or bruising over the collarbone. Diagnosis is typically made through a physical assessment, noting these specific symptoms and any asymmetry in the baby’s Moro reflex. A chest X-ray is often used to confirm the presence and location of the break.
Treatment and Recovery Outlook
The management of a neonatal clavicle fracture is almost always conservative, meaning it does not require surgery or a cast. Primary treatment involves ensuring the infant is handled gently to minimize pain and prevent further displacement of the fracture fragments. Parents are advised to support the baby’s body fully and avoid lifting the baby directly under the arms.
The arm on the side of the fracture may sometimes be immobilized for a short period to aid comfort and healing. This is typically achieved by securing the infant’s shirt sleeve to the front of their clothing, keeping the arm resting against the chest. Due to the rapid healing capacity of newborns, initial recovery is quick, with the bone often showing signs of healing within 7 to 10 days.
As the bone begins to knit together, a noticeable firm lump, called a callus, forms at the fracture site. This callus is a mass of new bone tissue and confirms that the healing process is underway. Full recovery is anticipated, and the fracture callus will gradually smooth out and disappear over the following months. Long-term complications are rare, and infants experience a complete recovery without lasting functional issues.