Congenital anomalies of the kidneys, collecting system, bladder, and urethra

• Based on strong research evidence, hydronephrosis is the most common cause of abnormal prenatal ultrasonography and abdominal masses in newborns. The urinary tract dilation classification system and the Society for Fetal Urology classification system are widely used for disease severity classification and management. (20)(22) • Based on strong research evidence, vesicoureteral reflux is the most common pediatric urologic condition, affecting up to 30% of children with a febrile urinary tract infection and 0.4% to 1.8% of the general pediatric population. (24) Management remains a controversial topic and is the subject of ongoing research. • Based on consensus, ultrasonography is the imaging of choice for initial evaluation prenatally and after birth to evaluate congenital anomalies of the kidney and urinary tract and is the image of choice for the initial evaluation of various diagnoses, to classify severity of disease, and to guide future monitoring. • Based on strong research evidence, posterior urethral valves are most commonly diagnosed prenatally with ultrasonography findings of bilateral hydronephrosis, dilated posterior urethra, and/or oligohydramnios. (45) Based on some research evidence as well as consensus, the treatment of choice is transurethral valve ablation. (47) • Based on strong research evidence, hypospadias is the most common malformation of the male genitalia. Newborn circumcision is contraindicated in these patients, and surgical repair is ideally performed at 6 to 12 months of age. (60).