Relationship Between Cavum Septi Pellucidi Measurements and Fetal Hypoplastic Left Heart Syndrome or Dextro-Transposition of the Great Arteries

Objectives-The aim of this study was to compare the size and position of the cavum septi pellucidi (CSP) in fetuses with hypoplastic left heart syndrome (HLHS) or dextro-transposition of the great arteries (d-TGA) with healthy fetuses. Methods-The CSP length, CSP width, and frontal lobe length were measured in 185 healthy fetuses (404 scans), 11 fetuses with HLHS (16 scans), and 11 fetuses with d-TGA (12 scans) between January 2005 and April 2016. Each measurement was compared between healthy fetuses and those with HLHS or d-TGA, controlling for the biparietal diameter. Results-Positive correlations were noted between biparietal diameter and CSP length, CSP width, and frontal lobe length (adjusted R-2=0.811, 0.821, and 0.878, respectively). An increased CSP length was found in both fetuses with HLHS and those with d-TGA (P<.0001). The CSP width was only increased in fetuses with d-TGA (P=.0466). No difference in the frontal lobe length was noted. Conclusions-In fetuses with HLHS, the CSP is increased in length. In fetuses with d-TGA, the CSP is increased in both length and width.