Single umbilical artery and associated birth defects in perinatal autopsies: prenatal diagnosis and management

Background: The umbilical cord forms the connection between the fetus and the placenta at the feto-maternal interface and normally comprises two umbilical arteries and one umbilical vein. In some cases, only a single umbilical artery (SUA) is present. This study was conducted to evaluate associations between SUA and other congenital malformations discovered in perinatal autopsies and to ascertain the existence of preferential associations between SUA and certain anomalies. Methods: We evaluated records of all fetuses sent for autopsy to the Department of Pathology during the 10-year period from 2013 through 2022 (n = 1,277). The data were obtained from the hospital's pathology laboratory records. The congenital anomalies were grouped by organ or system for analysis and included cardiovascular, urinary tract, nervous system, gastrointestinal tract, musculoskeletal, and lung anomalies. Results: A SUA was present in 8.61% of the autopsies. The gestational age of the affected fetuses ranged between 13 to 40 weeks. An SUA presented as an isolated single anomaly in 44 cases (3.4%). Of the 110 SUA cases, 60% had other congenital anomalies. There was a significant association between birth defects and SUAs (p < .001). Strong associations between SUA and urinary tract, lung, and musculoskeletal anomalies were observed. Conclusions: A SUA is usually seen in association with other congenital malformations rather than as an isolated defect. Therefore, examination for associated anomalies when an SUA is detected either antenatally or postnatally is imperative. The findings of this study should be helpful in counseling expectant mothers and their families in cases of SUA.