Sonographic assessment of the umbilical cord

The umbilical cord is crucially important feto-maternal unit, though very simple in structure while containing two arteries and one vein; it modulates blood flow conveyance between the fetus and placenta. Umbilical cord characteristics, such as cord length and thickness, number of vessels and their diameters, amount of Wharton's jelly, type of placental insertion, coiling and blood flow patterns are recognized contributors that may reveal increased risk for possible antenatal and perinatal complications. However, during the “routine” fetal anatomical survey, only the number of umbilical cord vessels is recorded in majority of antenatal centers. Thereafter, umbilical cord is rarely analyzed, except for umbilical artery blood flow patterns that are mainly used to further assess well-being of growth-restricted fetuses. At present time, it appears prudent to exercise more detailed umbilical cord analysis, including but not limited to vessel number, coiling patterns and cord thickness, during the fetal anatomical survey, because an abnormal presentation of these variables could be associated with adverse ante- and perinatal events.