Human Phenotype Ontology identifier HP_0001195 (Single umbilical artery) (SUA) is the absence of one of the two umbilical arteries surrounding the fetal bladder and in the fetal umbilical cord. Also known as: 2 vessel cord, 2 vessel umbilical cord, Only one artery in umbilical cord instead of two, SUA, Two vessel cord, Two vessel umbilical cord, Two-vessel cord.