One-Year Follow-Up of Radiologic and Clinical Findings in Children with Prenatal and Neonatal Hydronephrosis

Abstract: Background & Aims: Hydronephrosis is a common problem in prenatal and newborn infants diagnosed by ultrasonography. Bladder to ureter reflux, the upper or lower urinary tract obstruction, and neurogenic bladder are the most common causes of hydronephrosis in newborns and infants. Methods: In this study, 100 neonates and infants with hydronephrosis were observed clinically and laboratorically for one year. Patients were allocated to two groups of fetal and newborn infants by the time of detection of hydronephrosis. Classification of the severity of hydronephrosis was based on the anterior-posterior diameter of renal pelvis including: mild hydronephrosis (5-9 mm), moderate (10-15 mm), and severe (more than 15 mm). Results: Fifty four patients were boy and 46 were girl. Mean age of patients in first visit of fetal and newborn infants hydronephrosis were respectively 2.5 (79% asymptomatic) and 5 month (100% symptomatic). Causes of fetal hydronephrosis were: bladder to ureter reflux (45%), idiopathic hydronephrosis (41%), ureteropelvic junction obstruction (UPJO) (3.11%), physiological hydronephrosis (7.5%), and posterior urethral valve (8.3%). Bladder to ureter reflux was the most common cause of hydronephrosis in all of the patients (57%). The most common causes of mild and severe hydronephrosis were bladder to ureter reflux and ureteropelvic junction obstruction, respectively. In patients with fetal hydronephrosis, 100%, 30% and 6% of cases of severe, moderate, and mild hydronephrosis need surgery, respectively. Conclusion: Using ultrasonography in pregnancy led to the discovery of most asymptomatic fetal hydronephrosis more than infant hydronephrosis. Keywords: Prenatal hydronephrosis, Neonatal hydronephrosis, Vesicouretral reflux, Obstructive uropathy, Voiding cystourethrogram (VCUG