[Single umbilical artery: review of 12 cases].

The umbilical cord normally consists of three vessels, two arteries and one vein. The absence of one umbilical artery or single umbilical artery (SUA) has been associated with some adverse perinatal events, such as low birth weight, prematurity, congenital malformations and perinatal mortality. The authors present 12 cases of SUA confirmed by histologic examination and the principal maternal and perinatal features of these cases are analyzed. In our study there were a prematurity rate of 58%, a low birth weight rate of 66% and a perinatal mortality rate of 580/1000. Among our patients, 42% of the infants with SUA had major congenital malformations. An accurate examination of the umbilical cord at delivery is suggested, mainly because SUA is an important index to detect associated congenital malformations.