Intraventricular hemorrhage

Definition and Incidence

Intraventricular hemorrhage (IVH) refers to bleeding into the ventricles of the brain.
It is a condition noted mostly in extreme preterm babies.
The bleeding originates from the fragile capillary network of the subependymal germinal matrix.
Severe IVH is defined as hemorrhage into the ventricles with ventricular dilatation or periventricular hemorrhagic infarction (PVHI).
The incidence of severe IVH is 10% to 25% among survivors born at 24 weeks of gestational age.
The incidence drops significantly to less than 5% in neonates born at 28 weeks of gestation and higher.

The germinal matrix is the most vascular and metabolically active area of the brain in a baby born before 32 weeks of gestation.
This area lacks adequate structural support and begins to involute after 34 weeks of gestation.
The proposed mechanisms for bleeding include severe ischemia followed by reperfusion injury.
Fluctuations in cerebral circulation that fall outside the normal autoregulation range contribute to the injury.
Cerebral venous vasodilation, often following hypercarbia, and venous congestion are also major factors.

Chorioamnionitis and severe placental insufficiency increase the risk of IVH.
Fetal growth restriction and absent or reversed umbilical artery doppler flow are significant risk factors.
A need for extensive resuscitation at birth increases the likelihood of bleeding.

Asphyxia causing the disruption of capillaries leads to IVH.
Rapid fluid boluses and volume expansion cause sudden hemodynamic shifts.
Hypocarbia, hypercarbia, and the occurrence of pneumothorax are known contributors.
The presence of a hemodynamically significant patent ductus arteriosus (hsPDA) increases the risk.

Antenatal administration of corticosteroids and magnesium sulphate are highly protective.
Delayed cord clamping and the use of volume-targeted ventilation are associated with a decrease in IVH.

Symptoms evolve gradually over days to weeks.
Neonates may present with lethargy, apnea, tone abnormalities, and a tight popliteal angle.

This presentation involves rapid clinical evolution over several hours.
It manifests with a bulging fontanelle, a sudden drop in hemoglobin, and decreased consciousness.
Additional signs include spontaneous abnormal eye movements, hypotonia, decerebrate posturing, seizures, and severe hypotension.

IVH occurs with ventricular dilatation, occupying more than 50% of the ventricle.

This was previously referred to as grade IV IVH or parenchymal extension.
Neuropathologic studies show it is a separate lesion consisting of a venous hemorrhagic infarction.
It results from the obstruction of blood flow in the terminal vein by a large ipsilateral IVH.

CUS is the primary imaging modality for screening and diagnosis.
It provides an ideal acoustic window through the anterior fontanelle without radiation hazards.
Routine CUS screening is recommended for all newborns born before 32 weeks of gestation or weighing less than 1500 g.
The first screening ultrasound is typically performed between 7 and 14 days of life.
A second scan is performed between 36 and 40 weeks to screen for periventricular leukomalacia.

Also referred to as post-hemorrhagic hydrocephalus (PHH).
It may occur days to weeks after the initial IVH.
It is primarily caused by impaired cerebrospinal fluid (CSF) resorption or obstruction by particulate blood clots.

Lower grades of IVH (I and II) require no specific change in clinical care.
Supportive care aims to maintain stable cerebral perfusion by keeping blood pressure and blood gases in a normal range.
Preventive measures include avoiding rapid fluid boluses, hypercarbia, hypoxia, and pneumothorax.
Thrombocytopenia and coagulation disturbances should be corrected.
Transfusion of packed red blood cells may be required for large IVH to restore blood volume.

Serial ultrasound measurements are necessary to monitor ventricular size using the Levene index.
Clinical monitoring includes measuring head circumference on alternate days to detect excessive growth.
Serial therapeutic lumbar punctures can be used to remove CSF if communication exists with the subarachnoid space.
Slowly progressive PVD may resolve spontaneously.
Permanent CSF diversion with a ventriculoperitoneal (VP) shunt may be required for established hydrocephalus.

The severity of the IVH is the primary predictor of adverse short-term and long-term outcomes.
Even milder grades of IVH have an increased risk of cerebral palsy (CP) and cognitive impairment.
Newborns with PVHI have a significantly higher risk for neurodevelopmental deficits.
Localized PVHI can cause spastic hemiparesis, whereas extensive PVHI leads to quadriparesis and mental retardation.