Is antibiotic prophylaxis necessary in infants with obstructive hydronephrosis?

Area of Science:

• Pediatric Urology
• Nephrology
• Infectious Disease

Background:

• Severe hydronephrosis in infants, graded III or IV by the Society for Fetal Urology, often results from upper urinary tract obstruction.
• Urinary tract infections (UTIs) are a significant concern in infants with obstructive hydronephrosis.
• The role of antibiotic prophylaxis in preventing UTIs in this population requires further investigation.

Purpose of the Study:

• To investigate the relationship between the degree of upper urinary tract obstruction and the incidence and timing of UTIs in infants with severe obstructive hydronephrosis.
• To determine if antibiotic prophylaxis is warranted for infants diagnosed with severe obstructive hydronephrosis.

Main Methods:

• Retrospective analysis of 105 infants prenatally diagnosed with severe hydronephrosis (SFU grade III-IV) between 1994 and 2004.
• Patients were categorized by the type of obstruction: ureteropelvic junction (UPJ) obstruction (75 patients) or lower ureteral obstruction (30 patients).
• Evaluation of UTI incidence and clinical course during the first 12 months postnatally, without antibiotic prophylaxis.

Main Results:

• Overall UTI incidence was 36.2% (38/105 patients) within the first year.
• UTIs occurred predominantly before 6 months of age (92.8%), with a mean onset at 2.6 months.
• Lower ureteral obstruction showed a higher trend for UTIs (50%) compared to UPJ obstruction (30.7%, p=0.063). This difference was significant in surgical cases (54.2% vs 24.5%, p=0.011).

Conclusions:

• Infants with severe obstructive hydronephrosis experience a high incidence of UTIs, primarily before 6 months of age.
• Lower ureteral obstruction is associated with a greater risk of UTIs compared to UPJ obstruction.
• These findings support the recommendation for antibiotic prophylaxis in infants with severe hydronephrosis due to upper urinary tract obstruction.