Outcome and management of isolated severe renal pelvis dilatation detected at postnatal screening.

The aim of this study was to evaluate the incidence and outcome of isolated severe renal pelvis dilatation (RPD; APD>15<or=20 mm) in an unselected population of 2-month-old infants prospectively followed up for 12-14 months of life. Isolated severe renal pelvis dilatation was detected in 46 of the 11,801 (0.39%) infants screened. Nephro-urological investigations were initiated if RPD persisted, or if urinary tract infection (UTI) occurred during follow-up, and antibiotic therapy was administered only when UTI occurred. At follow-up, RPD persisted in 24 infants. Of these, 8 infants presented with vesico-ureteral reflux (VUR) of grade>or=3 and 16 with ureteropelvic junction obstruction (UPJO). Incidence of UTI was significantly higher (p<0.001) in infants of the study group than in infants of the control group (13.9 vs 2.5%). Our data suggest that isolated severe RPD may be a self-limiting condition and that antibiotic prophylaxis (AP) for the prevention of UTI should not be performed. Considering RDP resolution and the incidence of UTI during follow-up, investigations for uropathy in infants with isolated, severe RPD are justified in persistent cases, or when UTI occurs during follow-up. Careful clinical monitoring for signs of UTI and treatment of each episode of UTI may be sufficient and safe.