Antepartum fetal intracranial hemorrhage, predisposing factors and prenatal sonography: a review.

Our objective was to review current literature pertaining to antepartum fetal intracranial hemorrhage. To this goal we selected all manuscripts published in the English language regarding this topic obtained from a MEDLINE search for 1966 through January 1998. Additional sources were identified through cross-referencing. Antenatal fetal intracranial hemorrhage may occur spontaneously, or occur in association with various maternal or fetal conditions. Predisposing maternal conditions at risk for this occurrence include alloimmune and idiopathic thrombocytopenia, von Willebrand's disease, specific medications (warfarin) or illicit drug (cocaine) abuse, seizures, severe abdominal trauma inflicting subsequent fetal injury, amniocentesis, cholestasis of pregnancy and febrile disease. Predisposing fetal conditions include congenital factor-X and factor-V deficiencies, hemorrhage into various congenital tumors, twin-twin transfusion, demise of a co-twin, or fetomaternal hemorrhage. Currently, antepartum fetal intracranial hemorrhage may be diagnosed by imaging techniques including ultrasonography and less frequently, magnetic resonance imaging. Early real-time sonographic signs of intracranial hemorrhage consist of irregular echogenic patterns representing the associated hematoma that may clearly distort normal intracranial structures. Recent reports have suggested Doppler flow velocimetry and color Doppler imaging as additional tools in detecting fetal intracranial hemorrhage. Various types of antenatal fetal intracranial hemorrhages that have been visualized sonographically include intraventricular, periventricular, subependymal, parenchymal, subdural, and intracerebellar events. Active hemorrhages may be associated with fetal distress manifested by fetal heart rate changes. Infrequently, antenatal ultrasonographic depiction of intracranial hemorrhage may precede devastating sequelae such as hydrocephalus, hydranencephaly, porencephaly, or microcephaly. Due to the significant associated neonatal neurological impairment and potential medicolegal implications of antepartum fetal intracranial hemorrhage, it follows that obstetricians and sonographers should be familiar with predisposing factors and typical diagnostic imaging findings of these events.