Mild external ear malformations and renal tract abnormalities: a meta-analysis.

BACKGROUND: The association between isolated mild external ear malformations and urinary tract anomalies has not been sufficiently researched, and prevalence of renal abnormalities reported in different studies is controversial, which is the subject of considerable debate, currently causing confusion over which specific ear anomalies do and do not require imaging. Therefore, we examined this controversial issue by conducting a meta-analysis to asses the association of renal tract abnormalities in infants with isolated mild external ear malformations.

METHODOLOGY: A meta-analysis of all published case-controlled studies, published in all languages. 65 articles were found, but only 4 were relevant. Main outcome measure was prevalence of urinary tract abnormalities detected by ultrasonography. Four studies involving 32983 evaluable infants were identified. The combined results indicated that the risk, in a fixed effects model, of renal tract anomalies in infants with isolated mild external ear malformations was O.R 1.56 (95% CI 1.25-1.94)

CONCLUSIONS: This meta-analysis confirms a significant association between renal tract abnormalities and isolated mild external ear malformations.