It is a collection of blood under the scalp.
During the birthing process, the small blood vessels in the fetus’s head rupture as a result of minor trauma.
Specifically for a cephalohematoma, the small blood vessels that cross the periosteum rupture and serosanguineous or bloody fluid accumulates between the skull and the periosteum.
The periosteum is the membrane that covers the outer surface of all bones. The bleeding is gradual; therefore, a cephalohematoma is not evident at birth. A cephalohematoma develops in the hours or days after birth.
Because the accumulation of fluid is located between the periosteum and the skull, the boundaries of a cephalohematoma are defined by the underlying bone.
In other words, a cephalohematoma is limited to the area on top of one of the skull bones and does not cross the midline or suture lines.
Because the pool of blood is at the top of the skull and not under it, there is no pressure on the brain .
Causes of cephalohematoma
The cause of a cephalohematoma is the rupture of the blood vessels that cross the periosteum due to pressure on the head of the fetus during delivery.
During the birth process, pressure on the skull or the use of forceps or a vacuum extractor ruptures these capillaries, causing an accumulation of blood or serosanguineous fluid.
Factors that increase pressure on the fetal head and the risk of the neonate developing a cephalhematoma include:
- Long work.
- Prolonged second stage of labor.
- Weak or ineffective uterine contractions.
- Abnormal fetal presentation.
- Instrument-assisted delivery with forceps or vacuum extractor.
- Multiple pregnancies.
These factors contribute to the traumatic impact of the birthing process on the fetal head.
Cephalohematoma is a subperiosteal accumulation of blood that occurs with an incidence of 0.4% to 2.5% of all live births.
They are most common in primigravidae, large infants, infants in a posterior occipital or transverse occipital position at the onset of labor, and after instrument-assisted deliveries with forceps or a vacuum extractor.
For unknown reasons, cephalohematomas occur more often in men than in women.
Cephalohematoma is a minor condition that occurs during the birth process.
Pressure on the fetus’s head breaks small blood vessels such as when the head is compressed against the maternal pelvis during labor or pressure from the forceps or a vacuum extractor used to aid delivery.
The shearing action between the periosteum and the bone causes bleeding from the emissary and diploic veins. As blood collects, the periosteum moves away from the skull.
As the bleeding continues and fills the subperiosteal space, the pressure builds and the accumulated blood acts as a tamponade to stop the bleeding.
History and symptoms of cephalohematoma
A complete labor and delivery history is needed to identify newborns at risk of developing a cephalohematoma.
Due to the slow nature of subperiosteal bleeding, cephalohematomas are usually not present at birth, but develop hours or even days after birth.
Therefore, repeated inspection and palpation of the newborn’s head is necessary to identify the presence of a cephalohematoma. Ongoing evaluation to document the appearance of a cephalohematoma is important. Once a cephalohematoma occurs, changes in size continue to be evaluated and documented.
The most obvious sign of a cephalohematoma is a raised, smooth area on the newborn’s head. A firm, enlarged, unilateral or bilateral lump on top of one or more bones below the scalp characterizes a cephalohematoma.
The raised area cannot be transilluminated, and the overlying skin is generally not discolored or damaged. Cranial sutures define the boundaries of the cephalohematoma.
Diagnosis of cephalohematoma
There is no diagnostic test for a cephalohematoma. Diagnosis is based on the characteristic lump on the newborn’s head.
However, some providers may order additional tests, such as X-rays, CT scans, or ultrasounds to evaluate possible skull fractures or other problems under the skull, that could affect the newborn’s brain.
Additional tests are especially warranted if there are changes in the behavior of the newborn or other problems, such as respiratory, cardiovascular or neurological.
Treatment / Management
The treatment and management of a cephalohematoma are mainly observational. The mass of a cephalohematoma takes weeks to resolve, as the clotted blood is slowly absorbed.
Over time, the lump may feel harder as the collected blood calcifies. The blood then begins 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 cephalohematoma during resolution.
No attempt should be made to aspirate or drain the cephalohematoma. Aspiration is not effective because the blood has clotted. Additionally, entering the cephalohematoma with a needle increases the risk of infection and abscess formation.
The best treatment is to leave the area alone and give the body time to reabsorb the collected fluid.
Cephalohematomas usually do not present any problems for a newborn. The exception is an increased risk of neonatal jaundice in the first days after birth.
Therefore, the newborn should be carefully evaluated for a yellowish discoloration of the skin, sclera, or mucous membranes. Noninvasive measurements with a transcutaneous bilirubin meter can be used to detect the baby.
A serum bilirubin level should be obtained if the newborn shows signs of jaundice .