Cephalohematoma

Etiology

The etiology of cephalohematoma is the rupture of blood vessels crossing the periosteum due to the pressure on the fetal head during birth. During the birthing process, pressure on the skull from the rigid birth canal or the use of ancillary external forces such as forceps or a vacuum extractor can result in the rupture of these small and delicate blood vessels resulting in the collection of sanguineous fluid.[7] Factors that increase pressure on the fetal head and ultimately increase the risk of the neonate developing a cephalohematoma include the following:

• A prolonged second stage of labor
• Macrosomia, or increased size of the infant relative to the birth canal 
• Weak or ineffective uterine contractions
• Abnormal fetal presentation
• Instrument-assisted delivery with forceps or vacuum 
• Multiple gestations
• Presentation of occiput in transverse or posterior position during delivery
• Cesarean section initiated following the first stage of labor
• Coagulopathy [8]

These risk factors contribute to the traumatic impact of the birthing process on the fetal head. Aside from the birthing process, cephalohematoma may rarely occur in adults or juveniles following trauma or surgery.[2]

Epidemiology

Cephalohematoma occurs with an incidence of 0.4% to 2.5% of all live births.[3] For unknown reasons, cephalohematomas occur more often in male than female infants.[9][10]

The lowest incidence of cephalohematoma occurs in unassisted vaginal delivery (1.67%).[11] Cephalohematomas are more common in primigravidae, large infants, infants in an occipital posterior or transverse occipital position at the start of labor, and following instrument-assisted deliveries with forceps or a vacuum extractor.[3] Amongst instrument-assisted deliveries, cephalohematomas occur most commonly following vacuum-assisted delivery (11.17% of deliveries), compared to forceps-assisted and cesarean delivery (6.35%).[12][11] A cesarean section that is initiated before the commencement of natural labor, however, is not associated with cephalohematoma.[3] 

Pathophysiology

Cephalohematoma is a condition that most commonly occurs during the birthing process and rarely in juveniles and adults following trauma or surgery. External pressure on the fetal head results in the rupture of small blood vessels between the periosteum and calvarium. External pressure on the fetal head is increased when the head is compressed against the maternal pelvis during labor or when additional external forces are applied from instruments such as forceps or a vacuum that may be used to assist with the birth. Shearing action between the periosteum and the underlying calvarium causes slow bleeding. As blood accumulates, the periosteum elevates away from the skull. As the bleeding continues and fills the subperiosteal space, pressure builds, and the accumulated blood acts as a tamponade to stop further bleeding. 

History and Physical

A comprehensive history of labor and birth is necessary to identify newborns at risk of developing cephalohematoma. Factors that increase pressure on the fetal head and the risk of developing a cephalhematoma should be identified, including a prolonged second stage of labor, abnormal fetal presentation, macrosomia, and operative or surgical delivery.

Due to the slow nature of subperiosteal bleeding, cephalohematomas usually are not present at birth but instead become most noticeable within the first 1 to 3 days following birth. Therefore, repeated inspection and palpation of the newborn’s head is necessary to identify the presence of a cephalohematoma. Ongoing assessment to document the appearance of a cephalohematoma is important. Once a cephalohematoma is present, assessing and documenting changes in size is continued. Patients may initially present with a firm but increasingly fluctuant area of swelling over which the scalp moves easily.[2] A firm, enlarged unilateral or bilateral bulge on top of 1 or more bones below the scalp characterizes a cephalohematoma. The raised area cannot be transilluminated, and the overlying skin is usually not discolored or injured. Cranial sutures define the boundaries of the cephalohematoma. The parietal or occipital region of the calvarium is the most common site of injury, but a cephalohematoma can occur over any of the cranial bones. 

Evaluation

The diagnosis of cephalohematoma is largely a clinical one. Diagnosis is based on the characteristic bulge on the newborn's head that does not cross cranial suture lines. The bulge may be initially firm and become more fluctuant as time passes. In contrast to caput succedaneum and subgaleal hematoma, cephalohematoma becomes most apparent in the first 1 to 3 days following birth rather than being immediately apparent.[13][14] Some providers may request additional tests, including skull x-rays, computed tomography (CT) scans of the head, or head ultrasound for further evaluation.[15] Skull x-rays and CT imaging may be useful if there is suspicion of an underlying skull fracture. CT imaging and head ultrasound can be useful to evaluate for intracranial hemorrhage and to further define which extracranial compartment the hemorrhage is located.

Infants should be evaluated for bleeding diathesis, such as von Willebrand disease, which may have predisposed the infant to develop cephalohematoma.[2] Needle aspiration of the cephalohematoma is discouraged due to the risk of introducing infection and is only indicated if an infection is suspected. Escherichia coli is the primary pathogen associated with an infected cephalohematoma.[2][1][16]

Treatment / Management

Treatment and management of cephalohematoma are primarily observational. The mass from a cephalohematoma can take weeks to resolve as the clotted blood is slowly absorbed. Over time, the bulge may feel harder as the collected blood calcifies. The blood then starts to be reabsorbed. Sometimes, the center of the bulge begins to disappear before the edges do, giving a crater-like appearance. This is the expected course for the cephalohematoma during resolution.[17][18][19][20](B2)

One should not attempt to aspirate or drain the cephalohematoma unless there is a concern for infection. Aspiration is often not effective because the blood has clotted. Also, entering the cephalohematoma with a needle increases the risk of infection and abscess formation. The best treatment is to observe the area alone and give the body time to reabsorb the collected fluid.

Usually, cephalohematomas do not present any problems to a newborn. The exception is an increased risk of neonatal jaundice in the first days after birth. Therefore, the newborn needs to be carefully assessed for a yellowish discoloration of the skin, sclera, or mucous membranes. Noninvasive measurements with a transcutaneous bilirubin meter can be used to screen the infant. A serum bilirubin level should be obtained if the newborn exhibits signs of jaundice.

Rarely, calcification or ossification may occur in cases that do not resolve.[21][1] A skull x-ray or CT scan of the head is indicated in patients whose cephalohematomas have not resorbed within 6 weeks of birth.[2] Rather than absorbed, an ossified cephalohematoma has hardened and has a clearly defined outer and inner layer of the bone surrounding the lesion.[1][3] The inner layer of the ossified cephalohematoma is composed of the outer and inner table of the infant's calvarium, whereas the outer table is composed of the infant's sub-pericranial bone derived from the elevated pericranium.[1] The contour of the inner layer of the ossified cephalohematoma can follow either the convex shape of the calvarium or become concave, encroaching upon the intracranial compartment.[1](B3)

There is an ongoing debate regarding conservative management versus early surgical intervention for cephalohematoma, as there are currently no randomized controlled trials for reference. It has been suggested that early surgical intervention is not necessary if the cephalohematoma diameter is >50 mm unless other clinical indications are present.[10](B3)

In patients with later-stage ossification or calcification, the advocates for surgery argue that outcomes are superior with intervention at an earlier age due to the infant's natural molding process, decreased risk of elevated intracranial pressure, and cosmetic advantage.[2] A rare surgical indication for ossified cephalohematoma is persistent cosmetic disfigurement.[2](B3)

When indicated, ossified cephalohematoma can be treated safely surgically with craniotomy or craniectomy and cranioplasty, yielding good outcomes.[1][3] The surgical technique involves resection of the overlying newly formed bone, the soft tissue mass, as well as the underlying original bone.[1] Following removal, the underlying depressed region is often sectioned into multiple pieces and is remodeled as a bone graft. There are multiple techniques for cranioplasty, each with favorable outcomes and minimal, if any, residual evidence in the following years.[3] (B3)

Differential Diagnosis

When diagnosing cephalohematoma, it's crucial to consider other conditions that may present similarly. These differential diagnoses require careful evaluation to ensure accurate identification and appropriate management.

Caput Succedaneum

Caput succedaneum is scalp edema located above the epicranial aponeurosis and beneath the overlying skin. The swelling in caput succedaneum is poorly defined and crosses suture lines. In contrast to cephalohematoma, caput succedaneum is present at the time of birth and typically disappears in the following days.[2]

Subgaleal Hematoma

Subgaleal hematomas are located superficial to the periosteum and beneath the epicranial aponeurosis. Subgaleal hematoma may be associated with the rupture of emissary veins, becoming life-threatening, also presenting immediately after birth or a few hours later. In contrast to cephalohematoma, subgaleal hematomas are capable of crossing suture lines. 

Prognosis

The majority of cases (approximately 80%) of cephalohematoma resorb within the first month of life.[1] Children typically do not have an associated neurologic deficit as the cephalohematoma is superficial to the calvarium and not in contact with the brain parenchyma.[1] In rare instances, cephalohematomas may calcify or lead to cosmetic deformities, but these occurrences are uncommon and typically do not result in long-term adverse effects on the infant's health.

Complications

Rare complications associated with cephalohematoma include anemia, infection, jaundice, hypotension, intracranial hemorrhage, and underlying linear skull fractures (5% to 20% of cases).[2][22][23] Cephalohematomas may calcify or lead to cosmetic deformities, though such occurrences are infrequent.