Normally, the umbilical cord has 2 arteries and 1 vein. A single umbilical artery means that there is only one umbilical artery in the umbilical cord. During fetal development, the vessels of the cord can also change and atresia of the umbilical artery and thus one remaining umbilical artery can occur. A single umbilical artery is a marker for a chromosomal abnormality. A marker is a sign that is often seen in conjunction with other abnormalities and should be noticed if the pregnant woman has any other markers related to Down’s syndrome. If necessary, chromosomal diagnosis should be done. A simple single umbilical artery in a chromosomally normal fetus may result in fetal growth restriction, otherwise, there are no other adverse effects. A simple single umbilical artery is not an indication for fetal induction of labor.