Postnatal outcome of prenatally diagnosed severe fetal renal pelvic dilatation.

Objective: We correlated the prenatal severity with the postnatal outcome of prenatally detected renal pelvic dilatation (RPD).

Methods: Cases of prenatally detected RPD referred between January 2002 and December 2008 were included. Severe RPD was defined as an anterior-posterior diameter of 15 mm, mild and moderate dilatation was defined as 6 to <10 mm and 10 to <15 mm, respectively. Postnatal diagnosis, the need for surgery and the correlation with the prenatal severity was ascertained.

Results: Of the 762 patients with RPD, 492 (64.5%) were mild, 167 (21.9%) were moderate, and 103 (13.5%) were severe. The male:female ratio for the severe cohort was 5:1. Of the sever cases, 68% had progressive dilatation. Of the mild/moderate cases, 5% progressed to severe dilatation. PUJ obstruction was confirmed in 48 cases (60.8%), severe VUR in 11 cases (14%), VUJ obstruction in 5 cases (6%), PUV in 2 cases (2.5%), and a nonidentifiable cause in 13 cases (16.5%). Ten of the 48 (20.8%) babies with PUJ obstruction required surgery within the first year of life.

Conclusion: An obstructive cause is usually present in severe cases, which are more likely to require surgery if there is PUJ obstruction. A high male:female ratio was present in this group.