The possible causes of single umbilical artery are: First, chromosomal abnormalities, a portion of children with chromosomal abnormalities will have a single umbilical artery. Second, accidental factors, there are various environmental factors that can cause problems in the fetus when carrying a baby, no matter how hard the parents try it cannot be completely avoided, there is a possibility that the baby will have abnormalities, the only thing you can do is to reduce the chances. It is advisable to go to the hospital for maternity checkups during pregnancy to be able to detect problems and take early action.