Morphological patterns of fetal lateral ventricular border irregularities: descriptive study

OBJECTIVES: Alterations in the lateral ventricular borders have been documented in the prenatal diagnosis of certain fetal brain conditions. This study aimed to describe and classify the morphological patterns of lateral ventricular border irregularities (LVBI) and to discuss possible etiologies. METHODS: This multicenter retrospective study reviewed all cases of prenatally diagnosed LVBI at three centers between January 2014 and December 2022. Neurosonography and fetal magnetic resonance imaging were used to determine the type of LVBI, its location and the presence of other ependymal abnormalities. Data regarding other prenatally diagnosed malformations, maternal TORCH serology, genetic testing, autopsy findings and postnatal outcomes were collected. RESULTS: Sixty-six fetuses were included in the analysis. Genetic testing was performed in 30/66 (45.5%) cases. Termination of pregnancy was elected in 33/66 (50.0%) of cases, and 28/66 (42.4%) were liveborn (mean ± SD age at postnatal neurodevelopmental follow-up, 3.4 ± 1.2 years). Four main LVBI patterns were identified: protrusions (nodular or non-nodular), indentations (round or wedge-shaped), undulations and mixed. Nodular protrusions (19/66 (28.8%)) were observed with neuronal migration disorders (periventricular nodular heterotopia or tuberous sclerosis complex), whereas non-nodular protrusions (4/66 (6.1%)) were observed in cases of disruptive injury (intraventricular hemorrhage or intrauterine fetal cytomegalovirus infection). Round indentations (7/66 (10.6%)) were observed in the context of porencephalic cysts, whereas wedge indentations (15/66 (22.7%)) were typically consistent with either periventricular venous hemorrhagic infarction or cleft (schizencephaly) with an abnormal ependymal lining. Undulating or mixed patterns (21/66 (31.8%)) were often observed in association with other malformations of cortical development. CONCLUSIONS: Characterizing the pattern of LVBI can provide a framework for describing fetal brain anomalies and suggesting their etiologies. These morphological configurations may represent different developmental or disruptive etiologies, but causal relationships require further study. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.