Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) of the newborn, more precisely germinal matrix-intraventricular hemorrhage, is bleeding that originates in the fragile germinal matrix near the cerebral ventricles of the preterm infant and may extend into the ventricular system and, in severe cases, the surrounding brain. It is one of the most common and consequential neurological complications of prematurity, with risk and severity rising as gestational age and birth weight fall.

Definition

Neonatal intraventricular hemorrhage is bleeding arising from the subependymal germinal matrix of the preterm brain that may rupture into and distend the lateral ventricles, classically graded by the extent of intraventricular blood and any associated parenchymal hemorrhage.

Scope

This entry covers the anatomical origin of the hemorrhage in the germinal matrix, the factors that make the immature brain vasculature vulnerable, the widely used grading of severity, and the principal complications including posthemorrhagic ventricular dilatation and parenchymal involvement. It is a reference description of the condition and its prognosis and does not provide management protocols or individualized advice.

Core questions

• Why is the germinal matrix the source of hemorrhage in preterm infants?
• How is the severity of intraventricular hemorrhage graded?
• What are posthemorrhagic ventricular dilatation and periventricular hemorrhagic infarction?
• How does the grade of hemorrhage relate to neurodevelopmental outcome?

Key concepts

• Germinal matrix
• Fragile immature vasculature
• Fluctuating cerebral blood flow and pressure-passive circulation
• Grading of hemorrhage severity
• Posthemorrhagic ventricular dilatation and hydrocephalus
• Periventricular hemorrhagic infarction
• Cranial ultrasound screening

Mechanisms

The germinal matrix is a richly vascularized but structurally immature region near the ventricles that involutes as the brain matures; its thin-walled vessels are prone to rupture. In the sick preterm infant a pressure-passive cerebral circulation, fluctuations in blood flow and venous pressure, and disturbances of coagulation predispose these vessels to bleed. Hemorrhage may remain confined to the germinal matrix, rupture into the ventricles with or without ventricular distension, or be accompanied by hemorrhagic infarction of adjacent white matter. Volpe (2009) describes how this destructive lesion interacts with the developmental vulnerabilities of the preterm brain.

Clinical relevance

Because severe intraventricular hemorrhage is associated with posthemorrhagic hydrocephalus and with adverse motor and cognitive outcomes, cranial ultrasound surveillance of preterm infants and grading of any hemorrhage inform prognosis and counselling. The grade and any parenchymal involvement carry most of the prognostic weight. This material describes the condition and its outcomes and is not a basis for individual management decisions.

Epidemiology

Intraventricular hemorrhage is predominantly a disease of very preterm and very-low-birth-weight infants, and both its frequency and severity increase with decreasing gestational age. Cohort studies link higher grades, and complications such as shunt-requiring posthemorrhagic hydrocephalus, to worse neurodevelopmental outcomes, while even lower-grade hemorrhage has been associated with measurable risk in some series (Papile 1978; Adams-Chapman 2008; Bolisetty 2014).

Evidence & guidelines

The grading framework derives from the cranial-imaging classification introduced by Papile and colleagues (1978), and outcome data come from large preterm cohorts relating hemorrhage grade and its complications to later development (Adams-Chapman 2008; Bolisetty 2014). Mechanistic synthesis is provided by Volpe (2009) and the standard neonatal neurology reference (Volpe et al. 2018).

History

Subependymal and intraventricular hemorrhage was characterized as a major lesion of prematurity in the 1970s, when Papile and colleagues used computed tomography to describe its incidence and to propose a grading scheme that, with the later shift to cranial ultrasound, became the standard language for the condition. Subsequent decades clarified the germinal-matrix origin of the bleed and the prognostic importance of parenchymal involvement and posthemorrhagic ventricular dilatation.

Debates

How prognostically important is low-grade hemorrhage?

Severe hemorrhage and parenchymal infarction clearly worsen outcome, but whether isolated lower-grade germinal matrix or intraventricular hemorrhage independently affects neurodevelopment has been debated across cohorts with differing conclusions.

Key figures

• Lu-Ann Papile
• Joseph J. Volpe
• Linda S. de Vries

Seminal works

• papile-1978
• volpe-2009

Frequently asked questions

Where does neonatal intraventricular hemorrhage come from?

It originates in the germinal matrix, a fragile, highly vascular region near the ventricles of the immature brain whose thin-walled vessels are prone to rupture; the bleeding may then extend into the ventricular system.

Does the grade of hemorrhage matter for outcome?

Yes. Higher grades, particularly those with ventricular distension or associated parenchymal hemorrhagic infarction, carry a substantially greater risk of posthemorrhagic hydrocephalus and of later motor and cognitive impairment than lower-grade bleeds.