What is the major predisposing factor for development of subarachnoid hemorrhage in the preterm neonate?

What is the major predisposing factor for development of subarachnoid hemorrhage in the preterm neonate?

• A. Hypoxic event
• B. Intraventricular hemorrhage
• C. Birth trauma
• D. Seizure activity

Answer: (A)

When a preterm infant experiences a hypoxic event, the brain’s blood vessels respond with increased and fluctuating flow, while autoregulation is immature. The germinal matrix in these tiny infants contains extremely fragile capillaries, so these sudden changes in cerebral perfusion readily cause rupture and bleeding into the subarachnoid space. This linkage between hypoxia and rupture of delicate cerebral vessels explains why a hypoxic event is the major predisposing factor for subarachnoid hemorrhage in preterm neonates. While intraventricular hemorrhage can accompany SAH, the initiating stress—hypoxia—is the key factor that sets the stage for hemorrhage to develop.

When a preterm infant experiences a hypoxic event, the brain’s blood vessels respond with increased and fluctuating flow, while autoregulation is immature. The germinal matrix in these tiny infants contains extremely fragile capillaries, so these sudden changes in cerebral perfusion readily cause rupture and bleeding into the subarachnoid space. This linkage between hypoxia and rupture of delicate cerebral vessels explains why a hypoxic event is the major predisposing factor for subarachnoid hemorrhage in preterm neonates. While intraventricular hemorrhage can accompany SAH, the initiating stress—hypoxia—is the key factor that sets the stage for hemorrhage to develop.