Neurosonographic Assessment of the Corpus Callosum as Imaging Biomarker of Abnormal Neurodevelopment in Late-Onset Fetal Growth Restriction

Objective: To explore corpus callosum (CC) developmental differences by ultrasound in late-onset small fetuses compared with adequate for gestational age (AGA) controls. Study Design: Ninety four small (estimated fetal weight <10th centile) and 71 AGA fetuses were included. Small fetuses were further subdivided into fetal growth restriction (IUGR, n = 64) and small for gestational age (SGA, n = 30) based on poor perinatal outcome factors, that is, birth weight <3rd centile and/or abnormal cerebroplacental ratio and/or uterine artery Doppler. The entire cohort was scanned to assess CC by transvaginal neurosonography obtaining axial, coronal and nnidsagittal images. CC length, thickness, total area and the areas after a subdivision in 7 portions were evaluated by semiautomatic software. Furthermore, the weekly average growth of the CC in each study group was calculated and compared. Results: Small fetuses showed significantly shorter (small fetuses: 0.49 vs. AGA: 0.52; p < 0.01) and smaller CC (1.83 vs. 2.03; p < 0.01) with smaller splenium (0.47 vs. 0.55; p < 0.01) compared to controls. The CC growth rate was also reduced when compared to controls. Changes were more prominent in small fetuses with abnormal cerebroplacental Doppler suggesting fetal growth restriction. Conclusions: Neurosonographic assessment of CC showed significantly altered callosal development, suggesting in-utero brain reorganization in small fetuses. This data support the potential value of CC assessment by US to monitor brain development in fetuses at risk. (C) 2015 S. Karger AG, Basel