During which time frame does 90% of intraventricular hemorrhage occur?

The majority of intraventricular hemorrhage (IVH) cases, particularly in preterm infants, typically occur within the first 72 hours of life. This critical timeframe correlates with several physiological changes after birth, as premature infants often experience fluctuations in cerebral blood flow and oxygenation. These factors can lead to the rupture of fragile blood vessels in the brain's ventricles, where IVH develops. The risk is particularly heightened during the first few days due to the vulnerability of the immature brain structures.

In contrast, IVH is less common after this initial period, as the infant begins to stabilize and develop more mature vascular structures. Understanding the timing of IVH occurrence is crucial for NICU staff, as it helps in monitoring at-risk infants more closely during this specific window to potentially mitigate severe outcomes associated with hemorrhagic events.