Investigators at Montreal Children’s Hospital sought to determine the necessity of vesicoureteral reflux (VUR) screening in children with prenatally detected hydronephrosis (PHN). They report their experience with consecutive infants seen at their institution with postnatally confirmed PHN from 1998 to 2003. All patients with anatomic abnormalities of the urinary system were excluded from the analysis.
At the authors’ institution, some children with low-grade hydronephrosis (grades I and II) underwent screening for VUR with a voiding cystourethrogram (VCUG) while others did not, partly determined by whether they were followed by a urologist or nephrologist. All patients with high-grade hydronephrosis (Grade III or higher) underwent VCUG screening. Medical records of all children with PHN were reviewed for presence of VUR diagnosed by VCUG, circumcision status, gender, exposure to antibiotic prophylaxis, and diagnosis of urinary tract infection (UTI). Children with low-grade PHN were compared to those with high-grade PHN (grades III and IV). The primary outcome measure was development of a symptomatic or febrile UTI, after accounting for gender, circumcision, and VUR.
The study included 206 children with PHN, 148 with low-grade hydronephrosis and 58 with high-grade hydronephrosis. Of the 148 infants with low-grade hydronephrosis, 98 (66%) underwent a VCUG. Among the 155 children who underwent VCUG, the overall prevalence of VUR was 11%, and was not statistically different between those in the low-grade PHN group (9%) and those in the high-grade PHN group (14%). No UTIs were noted among patients with grade I hydronephrosis during 53 patient-years of follow-up. The incidence of UTI was 3.6 times higher among the high-grade PHN group (11.1 infections per 100 patient-years) than among the overall low-grade PHN group (3.52 infections per 100 patient-years). In multivariate analysis, UTI was significantly more likely among children with high-grade hydronephrosis than in children with low-grade hydronephrosis after correcting for gender and circumcision status. The association remained strong after also correcting for VUR status but was of borderline statistical significance (P = .053). Gender, circumcision, and VUR on antibiotic prophylaxis were not statistically significant independent risk factors for UTI.
The authors conclude that children with low-grade hydronephrosis and anatomically normal upper urinary tracts do not benefit from VCUG screening, since UTI risk appears to be associated with hydronephrosis grade rather than VUR.
Dr Shukla has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
PHN is the most common anomaly detected on routine prenatal sonography, seen in 1% to 3% of all pregnancies.1 The standard workup of children with a history of PHN has traditionally included a renal ultrasound and VCUG, but there is lack of consensus as to whether these studies are necessary since controlled trials with appropriately extended postnatal follow-up are...