Unilateral Renal Agenesis: Necessity of Postnatal Evaluation in a Contemporary Series

To assess the need for postnatal evaluation and the long-term consequences in patients with prenatal diagnosis of unilateral renal agenesis (URA).

A retrospective review of the records of all patients with prenatal diagnosis of URA between 2004 and 2013 was done. We included all patients who underwent postnatal evaluation with renal bladder ultrasound (RBUS), dimercaptosuccinic acid scan, and a voiding cystourethrogram. Long-term follow-up included physical examination and assessment of contralateral renal growth.

A total of 46 children (24 boys and 22 girls) with URA were identified. Ultrasounds showed associated hydronephrosis in 9 patients (19%). Dimercaptosuccinic acid scans confirmed the diagnosis of URA in all patients and showed renal scars in 2 solitary kidneys (4%). Vesicoureteral reflux was diagnosed in 4 patients (12%); all were of low grade and managed conservatively. After a mean follow up of 4 years, RBUS showed compensatory hypertrophy in 31 patients (67%), 3 patients (6%) developed chronic kidney disease, and 2 patients (4%) developed hypertension.

Prenatally detected cases of URA should be promptly evaluated. RBUS is found to be sufficient for diagnosis. However, additional imaging may be indicated for confirming the diagnosis and detection of other associated urinary anomalies. Serial assessment of the contralateral solitary kidney growth and serum creatinine measurement will be helpful to assess kidney function on the long term.