Mild dilatation of renal pelvis in term neonates with urinary tract infection.

The purpose of this study was to assess the incidence and evolution of mild dilatation confined to the renal pelvis in term neonates with urinary tract infection developing within 2 weeks from birth. Twenty-two neonates with mild dilatation of the renal pelvis out of 180 neonates with urinary tract infection were identified giving an incidence of 12.2% for this finding. Male to female ratio was 6.3:1. The left kidney was twice as frequently involved (68 vs. 32%). At follow-up, the dilatation had disappeared in 20 neonates (90.9%) by a mean age of 2.7 years with only one neonate developing two further episodes of urinary tract infection in the infantile period. No other morbidity was noted.