Fetal urinoma: two new cases and a review of the literature.

Objective: To evaluate the functional prognosis of kidneys affected prenatally by urinomas.

Methods: This was a retrospective review of cases of fetal urinoma reported in the literature, as well as two of our own cases.

Results: Twenty-three patients with a prenatal diagnosis of urinoma (five bilateral) were included in the analysis. Postnatal ipsilateral renal function was observed in only six of the 28 renal units (i.e. around 20%).

Conclusions: Although the precise causes of urinomas are still unknown, this review shows that in the event of a fetal urinoma, the probability of a non-functional dysplastic ipsilateral kidney lies at around 80%. In-utero puncture only appears to be justified in cases where fluid accumulation has mass effects on adjacent major structures.