What is the primary cause of neonatal subdural hematoma?

From the Guidelines

The primary cause of neonatal subdural hematoma is birth trauma, particularly during difficult vaginal deliveries. This condition occurs when blood vessels between the brain's surface and its outer covering tear during the birthing process, leading to blood accumulation in the subdural space. Instrumental deliveries using forceps or vacuum extraction significantly increase the risk, as does cephalopelvic disproportion where the infant's head is too large for the birth canal. Prolonged or precipitous labor can also contribute to this injury. Premature infants are especially vulnerable due to their fragile blood vessels and underdeveloped brain structures.

Symptoms may include seizures, lethargy, poor feeding, increased head circumference, bulging fontanelle, and neurological abnormalities. Management typically involves close monitoring for small hematomas that often resolve spontaneously, while larger collections may require neurosurgical intervention through burr hole drainage or craniotomy. Prevention focuses on appropriate obstetrical care, including careful assessment of delivery risks and judicious use of instrumental assistance. Although child abuse, as discussed in 1, and bleeding disorders, as mentioned in 1 and 1, can also be causes of subdural hematoma, the primary cause in the neonatal context is birth trauma.

Key factors to consider in the management and prevention of neonatal subdural hematoma include:

• Careful assessment of delivery risks
• Judicious use of instrumental assistance during delivery
• Close monitoring of infants for signs of subdural hematoma
• Prompt neurosurgical intervention when necessary
• Consideration of child abuse and bleeding disorders as potential causes, especially if the clinical presentation is atypical or if there are other suspicious findings, as noted in 1. However, birth trauma remains the most common and primary cause of neonatal subdural hematoma, and management should prioritize this etiology while also considering other potential causes.

From the Research

Causes of Neonatal Subdural Hematoma

The primary cause of neonatal subdural hematoma is related to birth trauma, particularly during difficult deliveries. Some key points to consider include:

• Birth-related subdural hemorrhage occurs in over a third of normal deliveries and has a characteristic distribution, predominantly in the posterior fossa 2.
• The incidence of subdural hemorrhage is higher in babies born by vaginal delivery, especially assisted vaginal delivery, compared to those born by cesarean section 3, 2.
• Forceps-assisted delivery is a recognized complication that can lead to subdural hematoma in neonates 4.
• Spontaneous subdural hematoma in infants can occur, but it is rare and often associated with idiopathic macrocrania, arachnoidomegaly, or dehydration 5.

Risk Factors

Some risk factors for neonatal subdural hematoma include:

• Difficult delivery, such as forceps-assisted or vacuum-assisted delivery 3, 4.
• Vaginal delivery, especially assisted vaginal delivery 2.
• Idiopathic macrocrania or arachnoidomegaly 5.
• Dehydration 5.
• Premature birth 6.

Clinical Presentation

Neonatal subdural hematoma can be asymptomatic or present with symptoms such as:

• Retinal hemorrhage 5, 6.
• Increased intracranial pressure 6.
• Abnormal head growth curves 5.
• Seizures or other neurological abnormalities 6.