Prenatal intracranial hemorrhage (ICH), also known as a brain bleed, is a potential fetal and neonatal alloimmune thrombocytopenia (FNAIT) complication, and specific imaging patterns could help physicians determine the cause of the bleed, according to a recently published abstract in Ultrasound in Obstetrics and Gynecology.
ICH has a broad range of underlying causes, which are often challenging to determine before birth. The emergence of advanced neuroimaging, combined with genetic diagnostics, offers new hope for understanding its origins. In this context, the authors aimed to characterize imaging features of ICH diagnosed in utero, focusing on how specific patterns correlate with specific causes.
Researchers analyzed 42 cases of prenatal ICH diagnosed between 2015 and 2024, excluding twin pregnancies and cases without comprehensive genetic evaluation. The study categorized cases into five groups: COL4A1/2 gene variants (a genetic disease that leads to blood vessel abnormalities), FNAIT, infections, other known causes and unknown etiologies. All cases were assessed using ultrasound and MRI to identify imaging patterns that could help differentiate between causes.
Among the identified causes, COL4A1/2 variants were most frequently associated with severe injuries. All nine cases in this group presented with hemorrhage in the ventricles, the hollow parts of the brain that produce spinal fluid. White matter injury was present in all, with a majority exhibiting extensive damage. Furthermore, complex structural abnormalities were frequent, highlighting the destructive potential of these mutations.
FNAIT was identified in four cases, typically presenting with focal hemorrhages: three with intraventricular hemorrhage and one with a bleed in brain tissue. Infectious causes included three parvovirus infections and one cytomegalovirus (CMV) case. Interestingly, cerebellar hemorrhage was observed in all three parvovirus cases.
Other causes were less common and included a case of maternal hypoxia, one with fetal coagulopathy, and another associated with a NOTCH3 variant. Despite exhaustive investigation, 22 cases (52.4%) had no definitive cause. H
The researchers emphasized that distinct imaging patterns can offer crucial diagnostic clues. COL4A1/2-related hemorrhages show extensive parenchymal and structural brain damage, while FNAIT and infectious causes exhibit more localized or pattern-specific findings. Recognizing these patterns prenatally could improve counseling, guide further diagnostic work-up, and influence perinatal management strategies.
“Understanding these imaging patterns may enhance prenatal diagnosis and management strategies for ICH,” the authors wrote.
Sign up here to get the latest news, perspectives, and information about FNAIT sent directly to your inbox. Registration is free and only takes a minute.
