Two Vessel Cord (Single Umbilical Artery)

As part of the routine 19-21 morphology scan the number of blood vessels in the umbilical cord are counted. The cord splits into 3 vessels after entering the baby’s abdomen; 2 pass downwards towards the baby’s bladder and one up through the baby’s liver. By looking with colour ultrasound, blood flowing through the vessels we are able  to count them. As long as there is one vessel entering and leaving the baby there will be a normal supply of blood, oxygen and nutrients to the baby. A 2 vessel cord therefore in itself does not result directly in any problems to the baby.


In fact in the vast majority of patients the pregnancy progresses uneventfully without complications and the 2 vessel cord is simply regarded as a variation of normal. There is however an increased chance of delayed growth in later pregnancy and an increased chance of associated fetal heart abnormalities. For this reason a careful examination of the fetal heart will be performed at the 19-21 week morphology scan when the majority of major cardiac abnormalities may be detected. Your doctor will also recommend a further ultrasound examination in late pregnancy.