Subgaleal hemorrhage is a medical condition that involves bleeding outside a newborn’s skull but beneath the scalp. This condition primarily affects infants after birth. Prompt recognition and medical intervention are important for management due to potential complications.
Understanding Subgaleal Hemorrhage
A subgaleal hemorrhage is a collection of blood in the subgaleal space, located between two layers of the scalp: the galea aponeurotica and the periosteum covering the skull. This loose connective tissue layer extends across the entire cranial vault and is not limited by the skull’s suture lines. Unlike other types of scalp bleeding, such as a cephalohematoma, a subgaleal hemorrhage can spread widely over the head.
Bleeding into this large, potential space can lead to substantial blood loss. A newborn can lose 20% to 40% of their total blood volume into this space, which can lead to severe blood volume depletion. Such substantial blood loss can result in hypovolemic shock, a life-threatening condition where the heart cannot pump enough blood to the body. This can cause systemic complications like anemia, hyperbilirubinemia, and organ failure due to reduced oxygen delivery to tissues.
Causes and Risk Factors
Subgaleal hemorrhages are caused by trauma to the head during labor and delivery. The primary mechanism involves the tearing or rupture of emissary veins, small blood vessels connecting the scalp’s veins to larger venous sinuses inside the skull. These veins are particularly susceptible to injury when significant pulling or shearing forces are applied to the infant’s head during birth.
Instrumental deliveries are a significant risk factor, with vacuum extraction being the most common cause. The suction from a vacuum extractor can pull the scalp away from the skull, rupturing emissary veins. Forceps delivery can also contribute by applying excessive pressure to the baby’s head. Other risk factors include a large baby size (macrosomia), prolonged labor, a first-time pregnancy, or when the baby’s head is too large to fit through the mother’s pelvis.
Recognizing the Signs
Signs of a subgaleal hemorrhage typically appear shortly after birth. A prominent indicator is swelling on the baby’s head, which is often described as diffuse, soft, and boggy (fluid-filled). This swelling is not confined by the skull’s suture lines and can spread across the entire scalp, distinguishing it from other types of birth-related head swellings. The swelling may cause earlobes to elevate and displace, and eyelids to become puffy.
Beyond scalp swelling, parents or caregivers might notice paleness due to blood loss. Signs of blood loss can also include a fast heart rate (tachycardia) and low blood pressure. The infant may exhibit neurological signs such as lethargy, poor feeding, irritability, or a high-pitched cry. These symptoms warrant immediate medical attention.
Diagnosis and Treatment
Medical professionals diagnose subgaleal hemorrhage through physical examination and diagnostic tests. A thorough physical assessment of the newborn’s head includes palpation for swelling characteristics and head circumference measurement. Monitoring vital signs, such as heart rate, blood pressure, and respiratory rate, provides information about the baby’s stability and potential blood loss. Laboratory tests, including hemoglobin and hematocrit levels, assess the extent of blood loss and check for anemia.
Imaging studies are used to confirm the diagnosis and determine the size of the hemorrhage. A head ultrasound is often the initial imaging choice due to its safety and effectiveness in newborns. In some cases, a CT scan or MRI may be used for a more detailed view or to rule out other conditions. Treatment primarily involves supportive care, including fluid resuscitation to restore blood volume and, for significant blood loss, blood transfusions. Close monitoring for complications like anemia, jaundice, and shock continues, and any underlying issues, such as clotting disorders, are managed.