Clinical Outcomes and Follow-Up in Children With Prenatally Detected Unilateral Ureteropelvic Junction Obstruction

To explore the possibility of reducing the diagnostic burden in children with prenatally detected unilateral ureteropelvic junction obstruction.

Children with unilateral ureteropelvic junction obstruction (2012-2020) were identified from a prenatal hydronephrosis registry. The frequency of adverse events, predictors for event-free follow-up beyond 1 year of age, and examination burden in children with conservatively managed unilateral ureteropelvic junction obstruction were assessed. Adverse events included febrile urinary tract infections, > 10% decline in differential renal function, or both, leading to surgery. Follow-up ended at clinical conclusion or surgical decision.

Forty-seven children were included, with a follow-up of median 22.5 (2-115, min-max) months. Overall, 43% (20/47) had no adverse events. Adverse events occurred within 2 years in 85% (23/27). Predictors of event-free follow-up beyond 1 year were a postnatal anteroposterior diameter < 15 mm at 12 months (p < 0.001) or a stable anteroposterior diameter during the first year (p = 0.04). Patients without adverse events underwent a median of eight (3-26, min-max) diagnostic imaging examinations.

In children with antenatally detected ureteropelvic junction obstruction, 43% had no adverse events, but a substantial examination burden. Predictors of a non-eventful trace, useful in guidelines, were a postnatal anteroposterior diameter < 15 mm or stable at 12 months.