UTI and VUR in children with mild antenatal hydronephrosis
Reviewed by Henrik Steinbrecher

This paper describes a retrospective analysis of 760 (608 males, 162 females) patients identified with mild antenatal hydronephrosis (defined by an anteroposterior (AP) pelvic diameter of 7-10mm in the third trimester and persistent postnatal dilation) looking at the incidence of vesicoureteric reflux (VUR) in this group. Thirty percent had bilateral hydronephrosis. Four hundred and seventy-five patients had an initial micturating cystogram (MCUG) of whom 13 had reflux (1.7%) graded between one to five. Two patients had posterior urethral valves. At follow-up hydronephrosis resolved in 67% (median time for resolution being 24 months) and worsened in 3.3%. Full follow-up was only available for 692 patients and 23 had documented urinary tract infection (UTI) (3.3%). Thirteen of 760 patients had surgery (two valve ablations, four reimplants due to breakthrough UTI, six pyeloplasties for worsening dilation, one tapering reimplant for vesicoureteric obstruction). The authors conclude that the incidence of UTI with mild antenatal hydronephrosis is low and that routine MCUG or the use of long-term antibiotics in this group is not warranted. 

Urinary tract infection and vesicoureteric reflux in children with mild antenatal hydronephrosis.
Sencan A, Varvas F, Hekimoglu I, et al.
JOURNAL OF PEDIATRIC UROLOGY
2014;10:1008-13.