A Novel Double-Line Sign in Axial and Sagittal View of Ultrasound of Fetal Abdomen to Identify Persistent Right Umbilical Vein.

Persistent right umbilical vein (PRUV) is an embryonic vascular developmental abnormality of the fetus with an associated anomaly rate of 13%-40.9%. PRUV can be identified in prenatal ultrasound using axial views of the abdomen. However, the diagnosis may be missed in routine axial views done for abdominal circumference, as oblique views are often required to view the gall bladder. We present a previously unreported and novel double-line sign in axial and sagittal views that we observed in 12 (0.1%) cases of PRUV identified in 11 989 s and third trimester antenatal scans done from 2015 to 2024 at the study institute. Pattern recognition of this new sign in the sagittal view will help to identify PRUV in difficult cases. The usefulness of the sagittal view to diagnose this condition has not been reported previously. The double-line sign seen on axial and sagittal views complement each other to establish the diagnosis of PRUV with certainty.