Prenatal diagnosis of malformations of cortical development by dedicated neurosonography

Objective: Malformations of cortical development (MCD) are rarely diagnosed in utero. We describe and compare the ultrasonographic and pathology findings in a cohort of fetuses with MCD.

Methods: Fetuses with MCD were identified among all fetuses evaluated for suspected brain anomalies at the Fetal Neurology Clinic, and the ultrasonographic findings were compared with the results of the pathology examination.

Results: We suspected the presence of MCD by ultrasonography in 23 fetuses. The mean gestational age at the time of ultrasound diagnosis was 26.2 (range, 18-40) weeks. The ultrasonographic findings leading to the diagnosis of MCD were abnormally overdeveloped gyri and sulci for gestational age (n = 7), delay in sulcation (n = 5), abnormally thin cortex (n = 5) abnormally wide and broad sulci (n = 3), bulging into the lateral ventricle (n = 1), cortical cleft (n = 1), and multiple intraparenchymal echogenic nodules (n = 1). All fetuses had associated central nervous system (CNS) and/or non-CNS anomalies. Pathology examination (performed in 17 fetuses) confirmed MCD in 16.

Conclusions: Cortical malformations can be diagnosed in utero by ultrasonography based on the presence of specific deviations from the normal pattern of development. The identified cases may represent the more severe forms in the MCD spectrum. The pathology findings do not always conform to the current classification systems of MCD but help in differentiating between possible genetic and acquired etiologies and in some cases provide a definitive syndromic diagnosis.