Prenatal ultrasonographic morphologic assessment of the umbilical cord: a review. Part II.

Ultrasonographic assessment, although not always possible throughout the entire length of the umbilical cord, may assist in the diagnosis of congenital and functional anomalies of this structure. In such fashion, prenatal ultrasound may outline normal anatomy or alternatively depict various congenital abnormalities of the umbilical cord including: cysts; pseudocysts umbilical vein varix; persistent right umbilical vein; angiomyxomas; aneurysm (arterial or venous); single, hypoplastic or fused umbilical artery; hematomas (spontaneous or iatrogenic); velamentous insertion; vasa previa. The umbilical cord coiling index, an additional ultrasonographic morphologic feature, may identify patients at risk for adverse perinatal outcome. Conditions of potential fetal compromise due to umbilical cord compression including nuchal cords, true knots, occult prolapse, cord presentation, fetal grasping, and cord entanglement in monoamniotic twins, may be detected prenatally; and impaired umbilical flow can be confirmed with Doppler flow velocimetry. Ultrasound has been widely used to guide invasive diagnostic and therapeutic procedures involving access to umbilical circulation. We conclude that the review of current literature supports that precise prenatal ultrasonographic depiction of the morphology of the umbilical cord may enhance perinatal management.