ABSTRACT
The normal umbilical cord contains two arteries and one vein. A single umbilical artery occurs in around 1% of cords in singletons, but the incidence may be higher in women with diabetes, and lower in those of African and Japanese ethnic origin. The antenatal diagnosis can be by examination of a transverse section of the cord using B mode, or by using colour Doppler to image the origin of the umbilical arteries on each side of the fetal bladder.
