Single umbilical artery and associated malformations in over 5500 autopsies: relevance for perinatal management.

With a birth prevalence rate of about 1%, single umbilical artery (SUA) is the most frequent of all congenital anomalies. It is recognizably associated with a variety of birth defects, but disagreement exists as to whether a SUA can predict an adverse perinatal outcome; disagreement also exists related to if, when present, other birth defects should be ruled out. The aims of the study were to estimate the association between SUA and other birth defects in a series of perinatal autopsies, to establish if preferential associations between SUA and certain birth defects exist, and to quantify the risks for other birth defects when a SUA is diagnosed.