Background and aims Fetal hydronephrosis is the most common anomaly detected on prenatal ultrasound examination. Several algorithms exist for its management but it remains controversy until now. Here we present our experience in management and outcome of the patients with prenatal hydronephrosis.

Methods In this study 160 known cases of prenatal hydronephrosis were evaluated for detecting underlying aetiology. We carried out renal and bladder sonography and voiding cystourethrography (VCUG) for all patients and DTPA scan in cases with suspicion of obstruction.

Results Of 160 cases of prenatal hydronephrosis 75% were boys and 25% were girls. The mean duration of postnatal follow up was 21.5 months (3 months to 36 months). The most common detected abnormalities were ureteropelvic junction obstruction (UPJO) 90 patients,vesicoureteral reflux (VUR) 46 patients, posterior urethral valve (PUV) 15 patients respectively. Nine patients had neurogenic bladder. Prenatal hydronephrosis were unilateral in 83.2% (133 cases). In these cases 57% were on the left side . The grade of reflux was severe in 20 renal units (36.4%), moderate in 24 renal units (43.6%), and mild in 11 renal units (20%). During the follow up period 50 cases (31.25%) resolved spontaneously. 34 cases (21.25%) underwent surgery and 76(47.5%) are still under medical treatment.

Conclusions It is highly suggested to do standard VCUG in all boys with prenatal hydronephsis to detect PUV and neurogenic bladder. Additionally, renal sonography in all cases of congenital hydronephrosis and DTPA in cases with indication is recommended.