Single Umbilical Artery and Associated Malformations in over 5500 Autopsies: Relevance for Perinatal Management

Abstract

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. In a series of 5539 perinatal autopsies conducted at the Hospital Materno Infantil Ramón Sardá and the Private Laboratory of Perinatal Pathology, Buenos Aires, Argentina, the rate of each malformation (grouped by organ/system) associated with SUA and the risks of associated malformations were estimated. In this series of autopsies, the rate of SUA showed a 10-fold increase when other malformations were present. The risk for other malformations increased significantly, by a 3-fold to 9-fold measure, when a SUA was present. Urinary and gut anomalies showed a preferential association with SUA. The absence of other birth defects lowered the risk of chromosome anomalies associated with SUA in 56% (odds ratio = 0.44). These results, obtained from a series of perinatal autopsies, are in agreement with most observations found in the literature, namely, high association rates between SUA and urinary and cardiovascular anomalies as well as a low risk for chromosome anomalies in SUA cases without other malformations.

Intestinal associations of a single umbilical artery

“…Single umbilical arteries have a known association with other congenital abnormalities,1 2 in particular hollow organ atresiae 3 4. However, in this case, a direct link between the unusual course of this single umbilical artery and the intestinal atresia is postulated.…”

Isolated Single Umbilical Artery as a Risk Factor for Urinary Tract Infections in Childhood

“…Importantly, postnatal imaging and autopsy examinations have suggested an increased prevalence of renal anomalies among fetuses in whom SUAs were classified prenatally as isolated. 8,11 Current literature does not advocate postnatal GU tract evaluation in iSUA neonates, as the majority of postnatally recognized renal anomalies are mild to moderate. 8,10,11 However, in light of our findings, it is possible that these mild to moderate anomalies contribute to an increased incidence of GU infections.…”

“…8,11 Current literature does not advocate postnatal GU tract evaluation in iSUA neonates, as the majority of postnatally recognized renal anomalies are mild to moderate. 8,10,11 However, in light of our findings, it is possible that these mild to moderate anomalies contribute to an increased incidence of GU infections. While the link between urinary tract anomalies and increased risk of infection in this population is speculative, the possibility begs further consideration of the value and utility of a thorough urinary tract evaluation in children with iSUA who present with a first-time UTI.…”

Congenital abnormalities of the urogenital tract: the clue is in the cord?

“…Two large studies5 6 demonstrated that the presence of an SUA is associated with an increased risk of congenital malformation, particularly renal tract abnormalities. Although the presence of an SUA is not diagnostically specific or sensitive, due to this increased risk it is wise to ensure the renal and reproductive tracts are fully visualised on imaging to exclude malformation.…”