Urinary tract infection in very low birth weight preterm infants.

Background: The prevalence of urinary tract infection (UTI) in preterm neonates ranges between 4 and 25%. The need for a radiologic investigation has not yet been established in very low birth weight premature newborns (<1500 g birth weight).

Patients And Methods: For an 11-year period (1990 to 2001), medical records of 62 very low birth weight premature infants admitted to a Level III neonatal intensive care unit and who developed UTI were reviewed retrospectively. Results of renal ultrasound and voiding cystourethrograms were compared between extremely low birth weight infants (birth weight, <1000 g) (Group A, Patient 34) and premature infants with birth weight between 1001 and 1500 g (Group B, Patient 28).

Results: UTI was more common in Group A (12.2%) than in Group B (5.7%) infants. Renal ultrasound detected mild renal pelvic dilatation (unilateral or bilateral) in 9 infants in Group A (26%) and in 1 infant in Group B (3.5%). Voiding cystourethrograms were performed in 26 of 34 (76%) infants in Group A and in 17 of the 28 (61%) premature infants in Group B. Vesicourethral reflux (VUR) was observed in 6 infants, 2 in group A (7.7%) and 4 in Group B (23%).

Conclusions: We found that the rate of VUR was lower in very low birth weight premature newborns than that reported in the medical literature among term newborns who developed UTI. VUR was less frequent in extremely low birth weight infants who developed UTI than in infants weighing 1001 to 1500 g.