Outcome after prenatal diagnosis of congenital anomalies of the kidney and urinary tract

Congenital anomalies of the kidney and urinary tract are common findings on fetal ultrasound. The aim of this prospective observational study was to describe outcome and risk factors in 115 patients born 1995–2001. All prenatally diagnosed children were stratified into low- and high-risk group and followed postnatally clinically and by imaging at defined endpoints. Risk factors were evaluated using odds ratios. Neonatal diagnosis included pelvi-ureteric junction obstruction (n = 33), vesicoureteral reflux (n = 27), solitary mild pelvic dilatation (postnatal anteroposterior diameter 5–10 mm; n = 25), and further diagnosis as primary obstructive megaureter, unilateral multicystic dysplastic kidney, renal dysplasia and posterior urethral valves. In 38 children with prenatal isolated hydronephrosis, ultrasound normalized at median age of 1.2 years (range 0.1–9). Surgery was performed in 34 children at median age of 0.4 years (0.1–10.8). Persistent renal anomalies without surgery were present in 43 children and followed in 36 for median time of 16 years (12.2–18). Oligohydramnios and postnatal bilateral anomalies were significantly associated with surgery and impaired renal function.

Conclusion: The majority of children had a favourable postnatal outcome, in particular children with prenatally low risk, i.e. isolated uni- or bilateral hydronephrosis. Oligohydramnios and postnatal bilateral anomalies were risk factors for non-favourable outcome.