Fetal intracranial hemorrhage is generally diagnosed in the late second trimester as an asymmetric echogenic mass within the ventricles, mostly associated with some degree of ventriculomegaly.
Causes to be considered include drug use (warfarin, cocaine), alloimmune thrombocytopenia, coagulation disorders, or trauma.
Grading of severity uses a similar scale to that for neonatal intraventricular hemorrhage (IVH), with prognosis being quite poor for most cases of Grades III or IV IVH.
The only specific treatment relates to situations in which the underlying cause is alloimmune thrombocytopenia, where aggressive therapy with IVIG and steroids in subsequent pregnancies may minimize recurrence.
Fetal intracranial hemorrhage refers to bleeding that occurs antenatally from a blood vessel into the ventricles, subdural space, or parenchyma of the brain. Whereas neonatal hemorrhage is a relatively common occurrence, affecting 40% to 60% of infants delivered before 32 weeks of gestation, fetal intracranial hemorrhage is quite rare. Factors that may place the fetus at risk for intracranial hemorrhage include alterations in maternal blood pressure, a maternal seizure disorder, placental abruption, specific medication or substance exposure (such as warfarin or cocaine), severe abdominal trauma, hereditary coagulation disorders (Komlósi et al., 2005) or alloimmune platelet disorders (Kuhn et al., 1992; Sherer et al., 1998; Lynch et al., 2002). Coagulation disorders associated with fetal intracranial hemorrhage incude factor V Leiden (Komlósi et al., 2005), Factor X mutations (Herrmann et al., 2005), prothrombin G20210A mutation, protein C or S deficiency, antithrombin III deficiency, and antiphospholipid antibody syndrome (Lynch et al., 2002).
Three types of intracranial hemorrhages can occur: intraventricular (or periventricular), intraparenchymal, and subdural. Intraventricular or periventricular hemorrhages are the most common, emanating from small vessels within the subependymal germinal matrix before 33 weeks of gestation (McGahan et al., 1984). The pathogenesis of intraventricular hemorrhage (IVH) is related to fragility of the capillary bed of germinal matrix, a disproportionate amount of total cerebral blood flow to the periventricular area, and the lack of autoregulation of cerebral blood flow in the fetus or premature infant. IVH is the most common form of intracranial hemorrhage seen in the neonate and is categorized in severity on a four-point scale, with the most severe fourth grade including parenchymal involvement (Lynch et al., 2002).
Intraparenchymal hemorrhages may be identified as distinct echogenic areas within the cerebral tissue, with or without displacement of the underlying ventricular or outer surfaces of the brain. As these hemorrhages evolve, they become hypoechoic and flattened as the hematoma liquefies. Residual changes may include development of a porencephalic cyst (see Chapter 21) or ventricular enlargement. Clots in the ventricular system are seen as bright echogenic areas that are similar to choroid plexus.
Subdural hematoma generally presents as fetal macrocephaly, with separation of the skull from the cerebral cortex. Hyperechoic and hypoechoic ...