title: Incidence of urinary tract infections in infants with antenatally diagnosed hydronephrosis-A retrospective single center study.
abstract: OBJECTIVE
  To evaluate the incidence of urinary tract infections (UTIs) in infants with antenatal hydronephrosis (AHN).
  
  
  METHODS
  A cohort of AHN patients admitted to our institution between 2003 and 2013 were identified. Altogether 192 patients with nonrefluxing hydronephrosis (HN, n=135), nonrefluxing hydroureteronephrosis (HUN, n=21), or vesicoureteral reflux (VUR, n=36) were identified. Patients with complex anomalies or neonatal decompression of the urinary tract were excluded. Information about UTIs diagnosed among the AHN patients was collected and compared with data from 58 controls.
  
  
  RESULTS
  During the median follow-up time of 2.6 (0.3-11.2) years, 24 (13%) patients (15 (10%) males and 9 (19%) females) and 2 (3%) controls experienced at least one UTI (p=0.033). Eighteen (69%) UTIs were febrile. The males had the first UTI at significantly younger age than the females (0.3, 0.0-1.7years vs. 1.0, 0.4-4.8years, p=0.010). UTI was detected in 15 (63%) patients with grade 4-5 VUR, in 8 (6%) patients with HN, and in one (5%) patient with HUN (p-values <0.001, 0.726 and >0.999 against the controls). None of the patients with grade≤3 VUR had UTI. Fifty-eight percent of the patients with UTI were on antimicrobial prophylaxis. In five (12%) cases UTI appeared within one week after voiding cystourethrography (VCUG).
  
  
  CONCLUSIONS
  Infants with AHN and grade 4-5 VUR had the highest risk of UTI. UTIs tented to be more common in females than in males; however, males experienced UTI at younger age than females. VCUG caused UTI in 2.3% in our material.
  
  
  METHODS
  III.
authors.affiliation: Department of Pediatric Surgery, Helsinki University Hospital, Helsinki, Finland. Electronic address: sofia.visuri@fimnet.fi.
authors.forename: Sofia
authors.initials: S
authors.lastname: Visuri
authors.affiliation: Department of Pediatric Nephrology and Transplantation, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland.
authors.forename: Timo
authors.initials: T
authors.lastname: Jahnukainen
authors.affiliation: Department of Pediatric Surgery, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Seppo
authors.initials: S
authors.lastname: Taskinen
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006869:Hydronephrosis / Q000150:complications* / Q000517:prevention & control; D015994:Incidence; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000209:etiology*; D014554:Urination; D014718:Vesico-Ureteral Reflux / Q000150:complications* / Q000151:congenital
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antenatal; Children; Hydronephrosis; Hydroureteronephrosis; Urinary tract infection; Vesicoureteral reflux