The umbilical cord usually contains two arteries and one vein. The vein carries the oxygenated blood from the placenta to the fetus. The arteries carry the deoxygenated blood and the waste products from the fetus to the placenta. Occasionally, primary agenesis or secondary atrophy of one of the arteries occurs resulting in single umbilical artery.
Keywords: Congenital anomalies; single umbilical artery; two vessel umbilical cord.