Outcome: the fetus died spontaneously one week later. The parent refused the autopsy.
Intracranial hemorrhage
Definition
- Bleeding within fetal cranium.
- An intracranial hemorrhage (ICH) is a collection of extravasated blood occurring in the fetal brain, usually affecting the lateral ventricles, although it can occasionally be found in other parts of the brain.
Synonymous: germinal matrix hemorrhage, intraventricular hemorrhage, intraparenchymal hemorrhage and subdural hematoma.
Prevalence: Overall estimated incidence of 1:10,000 pregnancies.
Etiology
- Alterations in maternal-fetal blood pressure:
+ Maternal seizure disorder-acute abdomen
+ Drug use: Cocain, aspirin
+ Maternal hemorrhagic disorders, maternal hypotension, HELLP syndrome.
+ Complications of monochorionic twin pregnancies
- Trauma: fetal subdural hematomas can be caused by trauma
- Maternal thrombocytopenia-coagulation disorders:
+ Immune thrombocytopenic purpura, alloinmune thrombocytopenia, and hidden antiplatelet autoantibodies.
+ Factor V or X deficiency, coumadin therapy
- Bacterial/viral infection
-Abnomalies of umbilical cord, placenta, amniocentesis complication
Pathogenesis: postnatally, most intraventricular hemorrhages originate in the subependymal germinal matrix region. In the premature brain, the germinal matrix contains thin-walled friable vessels supported by a delicate matrix that is easily injured by any elevation of the cerebral blood pressure, as in fetal hypoxia or thrombosis. It is unclear whether the pathophysiology is the same in intrauterine hemorrhage.
Ultrasound diagnosis:
- Hemorrhage usually extensive when diagnosed in utero: normal intracranial landmarks often obscured
- Intraparenchymal
+ Hyperechoic mass within parenchyma
+ Porencephaly develops with time
- Subependymal
+ Same appearance/grading as neonatal GMH
- Intraventricular
+ Hyperechoic intraventricular clot
+ Irregular bulky choroid plexus
+ Echogenic, irregular ependyma
+ Hydrocephalus
- Subdural
+ Hyperechoic material outlining cortex
+ Separates Sylivian fissure from calvarium: normal distance cortex to skull vault ≤ 4mm.
Classification: ICH is commonly classified by severity into four grades, as follows:
- Grade I: limited to the subependymal matrix
- Grade II : clear spillover to the ventricles but filling less than 50% of the lateral ventricle (without acute ventriculomegaly)
- Grade III: spillover to the ventricles with filling more than 50% of the lateral ventricle (with acute ventriculomegaly)
- Grade IV: characteristics of grades I to III with destruction of periventricular parenchyma
Differential diagnosis:
- Intracranial tumor
+ Large, heterogeneous, rapid growth
+ Caution: intracranial tumors may bleed, look for blood flow in periphery of mass with color Doppler. Clot is not perfused, tumor will show flow
+ Macrocephaly common
+ Choroid plexus papilloma is a potential mimic for intraventricular clot
- Infection
+ May cause detructive brain lesions
+ Intracranial/liver calcifications, hydrops.
- Ischemia
+ Periventricular leukomalacia
Prognosis: the prognosis for ICH largely depends on the severity of the condition, which ranges from mild neurologic deficits to neonatal death. A 50% perinatal death rate and 50% neurologic compromise in survivors have been reported, and the grade of hemorrhage correlates with the severity of the prognosis. The risk of recurrence depends on the underlying cause. Patients with alloimmune thrombocytopenia carry a very high (85% to 90%) recurrence risk of ICH.
Management: the management options are mainly based on timely termination of pregnancy in severe cases, and conservative approaches including early postnatal neurological evaluation, shunting operation, and implementing special rehabilitation program in milder cases.
Referrences:
1. Joshua A. Copel et al (2012), Obstetric Imaging, Intracranial Hemorrhage, p. 236 – 237.
2. Paula J. Woodward, Anne Kennedy, Roya Sohaey, Janice L.B. Byrne, Karen Y. Oh, Michael D. Puchalski (2005), Diagnostic Imaging Obstetrics, Intracrainal Hemorrage, p. 2-64 – p.2-68