Germinal Matrix-Intraventricular Haemorrhage (GM-IVH) is the most common form
of intracranial haemorrhage in preterm infants. It can occur in up to 20%
of infants delivered at less than 32 weeks gestation.
Pathophysiology
The site of origin of GM-IVH is at the subependymal germinal matrix.
This is the area of the brain where neuroblasts migrate from between 10 and 20
weeks, and becomes the source of glioblasts. It is a very vascular
structure. At a microscopic level, destruction of the germinal matrix
occurs when there has been a GM-IVH.
In approximately 15% of infants, there is also intraparenchymal involvement.
This was previously though to represent parechymal extension of an
intraventricular haemorrhage. It is associated with an ipsilateral GM-IVH
in 80% of cases. However, it is now thought to represent periventricular
haemorrhagic venous infarction, due to occlusion of medullary veins which return
adjacent to lateral ventricle and germinal matrix.
Terminology and Classification
GM-IVH is frequently described according to where the bleed is, and how
extensive. However, most neonatal units also use a grading system (Grades
1 to 4) according to extent of the haemorrhage. This is useful for audit
purposes and for some prognostic categories, but is not as precise as a detailed
description in this regard.
For the purposes of this website, images are presented according to their
Papile grading 1. Links to the
left will take you to the appropriate images.
The grading system is as follows:
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- Germinal matrix haemorrhage
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- Extension into the lateral ventricle(s), with haemorrhage filling
less than 50% of the ventricular area
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- Extensive haemorrhage with distension or dilatation of the lateral
ventricles
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Grade 1 and 2 haemorrhage make up about 75% of IVH.
1.
Papile LA, Burnstein J, Burnstein R, et al. Incidence and evolution of
subependymal and intraventricular hemorrhage: a study of infants with
birth weights less than 1,500 gm. J Pediatr 1978; 92;529-34.
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Ministry of Health
