Fetal Intracranial Hemorrhage: What to Tell Expecting Parents?

ABSTRACT To review the classification, epidemiology, etiology, prenatal diagnostic approach, and neurodevelopmental outcomes of fetal intracranial hemorrhage (ICH), and to provide clinicians with a practical, fetal‐specific framework for investigating and counseling families facing this diagnosis. Narrative review of the current evidence on fetal ICH, encompassing intraventricular hemorrhage (IVH) and periventricular hemorrhagic infarction (PVHI), cerebellar hemorrhage, and extra‐axial bleeding, with a primary focus on IVH as the most common presentation. The true prenatal incidence of fetal ICH is uncertain, with estimates of 0.5–1 per 10,000 pregnancies likely underestimating the true burden. Etiologies are diverse, including fetal‐neonatal alloimmune thrombocytopenia (FNAIT), monogenic vasculopathies (notably COL4A1/COL4A2 ), congenital infection, fetal anemia, coagulopathy, and twin‐related complications; however, a definitive cause is identified in fewer than half of cases even after complete workup, with a genetic etiology found in roughly 30% of fully investigated cases. Detailed neurosonography remains the primary diagnostic tool, with fetal MRI serving as an important adjunct for characterizing hemorrhage extent, associated parenchymal injury, and posterior fossa involvement. Outcomes vary substantially by hemorrhage grade, location, and laterality: low‐grade IVH generally carries a favorable prognosis, while PVHI—for which the Bassan territorial classification aids prognostication—carries substantially higher rates of cerebral palsy, ventriculoperitoneal shunting, and cognitive impairment, particularly when extensive and bilateral. Existing prognostic data derive largely from small, heterogeneous neonatal cohorts using a grading system not designed for the fetal context, limiting the precision of individualized counseling. Fetal ICH is rare, etiologically heterogeneous, and variable in severity, and current evidence does not support precise individualized outcome prediction. A thorough, systematic evaluation and an interdisciplinary team approach are essential, with transparent communication about the inherent uncertainties forming the foundation of parental counseling.