Unilateral renal agenesis: a systematic review on associated anomalies and renal injury

Nephrol Dial Transplant. 2013 Jul;28(7):1844-55. doi: 10.1093/ndt/gft012. Epub 2013 Feb 28.


Background: Unilateral renal agenesis (URA) is associated with other congenital anomalies of the kidney and urinary tract (CAKUT) and extra-renal anomalies. However, the reported prevalences of these anomalies are highly variable. We estimated the prevalence of associated CAKUT and extra-renal anomalies in patients with URA. Furthermore, we determined the prevalence of renal injury in URA patients.

Methods: We conducted a systematic review of English and non-English articles using PubMed and Embase.com. Included studies reported at least one of the following items: incidence of URA, gender, side of URA, prenatal diagnosis, performance of micturating cystourethrogram, associated CAKUT, urinary tract infection or extra-renal anomalies. Studies that described a mean/median glomerular filtration rate (GFR) and proportions of patients with hypertension, micro-albuminuria or a decreased GFR were also included.

Results: Analyses were based on 43 included studies (total number of patients: 2684, 63% male). The general incidence of URA was 1 in ∼2000. Associated CAKUT were identified in 32% of patients, of which vesicoureteral reflux was most frequently identified (24% of patients). Extra-renal anomalies were found in 31% of patients. Hypertension could be identified in 16% of patients, whereas 21% of patients had micro-albuminuria. Ten per cent of patients had a GFR<60 mL/min/1.73 m2;.

Conclusions: These aggregate results provide insight in the prevalence of associated anomalies and renal injury in patients with URA. Our systematic review implicates that URA is not a harmless malformation by definition. Therefore, we emphasize the need for clinical follow-up in URA patients starting at birth.

Keywords: congenital anomalies of the kidney and urinary tract; renal injury; solitary functioning kidney; systematic review; unilateral renal agenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Congenital Abnormalities / pathology*
  • Humans
  • Kidney / abnormalities*
  • Kidney / injuries*
  • Kidney / pathology
  • Kidney Diseases / complications
  • Kidney Diseases / congenital*
  • Kidney Diseases / pathology
  • Meta-Analysis as Topic
  • Prognosis
  • Review Literature as Topic
  • Urinary Tract / abnormalities*
  • Urinary Tract / injuries

Supplementary concepts

  • Hereditary renal agenesis