A normal fetal umbilical cord contains two umbilical arteries and one umbilical vein within the Wharton's jelly. A single-artery umbilical cord is one of the most common umbilical cord abnormalities that can be life-threatening to the fetus if not detected early.

A single artery umbilical cord is discovered through a routine ultrasound check-up, causing many pregnant mothers to worry. So what is a single artery umbilical cord, is it an abnormality of the fetal umbilical cord, and does it affect the development of the fetus?