Risks of Renal Anomalies and Urinary Tract Infections in Neonates With Single Umbilical Artery

Background Our study aims to evaluate the characteristics of congenital anomalies of kidneys and urinary tracts (CAKUT) and urinary tract infection (UTI) in babies with single umbilical artery (SUA) and to identify factors associated with these outcomes. Methods We performed a 15-year retrospective analysis on babies who were born ≥34 weeks with SUA between 2006 and 2020. Relevant clinical information on obstetrics and neonatal examinations, UTIs, and imaging of the urinary systems was evaluated. Results The frequency of SUA in newborns was 3.28 per 1,000 deliveries. The majority (271/291; 93.1%) of patients had kidney ultrasound, and 19 (7.0%) had CAKUT. Hydronephrosis (n = 11, 57.9%) was the commonest CAKUT, followed by unilateral kidney agenesis (n = 3, 15.8%), horseshoe kidney (n = 2, 10.5%), and right low-lying kidney (n = 2, 10.5%). Most significant CAKUT (including solitary kidney and urinary tract obstruction) could be detected during the antenatal period. Congenital heart defect (OR 4.93, 95% CI 1.59-15.34), limbs (OR 9.77, 95% CI 1.53-62.44), and sacral abnormalities (OR 5.06, 95% CI 1.25-20.55) were associated with CAKUT. Six (2.1%) developed UTIs during the study period, with the majority below two years old. The presence of CAKUT was associated with the development of UTI after adjustment (adjusted HR 10.28, 95% CI 1.86-56.83). Conclusions The overall prevalence of CAKUT was 7.0% in patients with SUA, and the majority of significant CAKUT was identified during the antenatal period. Congenital heart defects, limbs, and sacral abnormalities were associated with CAKUT. UTI occurred in 2.1% of patients.