OP12.02: Assessment of brain volume and cortical development in fetuses with congenital aortic abnormalities

To establish a database of normal fetal brain and evaluate brain volume and cortical development in fetuses with congenital aortic abnormalities (CAA). Fetal brain volume and sulcal measurements were performed on routine prenatal examinations of fetuses at 18-40 weeks gestation. 3D volume data of the fetal brain were acquired, and the VOCAL software was used to measure volumes of total brain, frontal lobe and thalamus. The depth, width and angle of the Sylvian fissure (SF), depth of the parieto-occipital fissure and calcarine fissure were measured at different gestational ages. Fetuses diagnosed with CAA were involved as study group, all measurements mentioned before were performed and hemodynamic indices (middle cerebral artery and umbilical artery) were measured. A total of 2584 normal fetuses were included and divided into 23 groups according to gestational age (18-40 weeks). Both volumes of frontal lobe and thalamus increased and had a good linear relationship with gestational age. Reference equations were constructed for characters of brain development. 235 fetuses with CAA were included in the study group. Compared with the reference value summarised with normal fetuses, only volume of frontal lobe was smaller in study group (P < 0.05). Width and depth of the SF was below the equation line and the angle of SF was greater in fetuses with aortic stenosis (n = 32), aortic valve lesions (n = 29), aortic coarctation (n = 41) and aortic interruption (n = 11), especially in fetuses with aortic coarctation and aortic interruption (P < 0.001). Measurements related to fetal brain development are significantly positively correlated with gestational age. Fetuses in CAA may affect cerebral development which characterised by decreased measurements of brain volume and sulcus. The more severe the phenotype, the more significant the difference.