A subgaleal hemorrhage (SGH) is a rare form of bleeding in newborns. It involves the accumulation of blood in the potential space between the galea aponeurotica, a dense fibrous sheet of tissue covering the cranium, and the periosteum, the membrane covering the skull bones. This condition is a serious medical concern because the subgaleal space is extensive and can hold a substantial portion of a newborn’s total blood volume, making it a life-threatening event that requires immediate intervention.
Causes and Risk Factors
Subgaleal hemorrhage is most often the result of birth trauma, with difficult deliveries being the primary cause. The most significant risk factor is the use of instruments to assist with delivery, particularly vacuum extraction (ventouse). The suction and traction forces applied by the vacuum cup can cause the rupture of small emissary veins that pass from the scalp through the skull, allowing blood to pour into the subgaleal space.
Forceps-assisted deliveries also increase the risk of this type of injury, although less commonly than vacuum extraction. The mechanical forces exerted during these procedures can create a shearing effect on the layers of the scalp, leading to venous rupture. Certain delivery scenarios heighten this risk, including prolonged or difficult labor, a baby who is very large for its gestational age (fetal macrosomia), or an unusual presentation of the baby’s head during birth.
While instrumental delivery is the most common precursor, SGH can also occur after spontaneous vaginal deliveries or cesarean sections, though this is far less frequent. Underlying conditions in the newborn, such as congenital bleeding disorders like hemophilia, can also contribute to the risk, as they affect the blood’s ability to clot properly following any trauma.
Symptoms and Diagnosis
A healthcare provider diagnoses SGH through clinical assessment, as the presentation is often distinct. The most prominent sign is a diffuse swelling on the infant’s head that feels soft and boggy, which typically becomes apparent within 12 to 72 hours after birth. A defining characteristic of this swelling is that it crosses the suture lines of the skull. This feature helps distinguish it from a cephalohematoma, where the bleeding is confined beneath the periosteum of a single skull bone.
As blood continues to fill the subgaleal space, the swelling can shift with the baby’s position and may displace the ears forward or cause bruising around the eyes. Due to the significant volume of blood loss, affected infants often show systemic signs of distress. These include pallor, a rapid heart rate (tachycardia), and other symptoms of hypovolemic shock, such as poor perfusion and a drop in blood pressure. Irritability and poor feeding are also common observations.
Diagnosis includes serial measurements of the head circumference to track the swelling. While the physical signs are often clear, imaging tests such as a head ultrasound or a CT scan may be used to confirm the extent of the bleeding or to rule out other injuries, like a skull fracture. Laboratory tests to check hemoglobin and hematocrit levels are performed to quantify the degree of blood loss.
Treatment and Management
A diagnosed subgaleal hemorrhage is treated as a medical emergency that requires immediate admission to a Neonatal Intensive Care Unit (NICU). The management is supportive, with the main goal of stabilizing the infant while the bleeding stops and the body begins to reabsorb the collected blood. There is no specific procedure to drain the blood; instead, treatment focuses on managing the consequences of the blood loss.
The primary treatment is volume resuscitation, which involves administering intravenous (IV) fluids to restore circulatory volume. In cases of significant blood loss, transfusions of packed red blood cells and fresh frozen plasma are necessary to replace lost blood and provide clotting factors. Vitamin K is also administered to correct any underlying deficiencies that could impair coagulation.
Continuous monitoring is a part of management. Medical staff will closely track the infant’s vital signs, including heart rate, respiratory rate, and blood pressure. They will also perform serial measurements of the infant’s head circumference and check blood levels of hemoglobin and hematocrit to assess for ongoing bleeding.
Prognosis and Potential Complications
The outcome for an infant with a subgaleal hemorrhage is dependent on the severity of the bleed and the speed with which it is diagnosed and treated. With early detection and supportive care, many infants can make a full recovery. The mortality rate is estimated to be between 12% and 25%, with death usually resulting from profound hypovolemic shock when the blood loss is massive or treatment is delayed.
The most immediate complication is hypovolemic shock, which occurs when the infant loses a critical volume of blood. Another issue is severe hyperbilirubinemia, or jaundice, which develops as the large amount of pooled blood breaks down. In severe cases, the lack of adequate blood flow can lead to hypoxic-ischemic encephalopathy, a type of brain injury that can result in long-term neurological problems such as cerebral palsy or developmental delays.
Following discharge, infants who have had a significant SGH require follow-up monitoring. These appointments are important to track their development and address any potential long-term issues from the initial injury.