**3.2 Lower urinary tract obstructions**

There are several congenital anomalies that result in chronic lower urinary tract obstruction, the most familiar being posterior urethral valves (PUV). Other inborn causes of lower urinary tract obstruction include urethral atresia, stenosis or hypoplasia; anterior urethral valves; urethral diverticula; and cloacal anomalies. Congenital lower urinary tract obstructions put both kidneys at risk for abnormalities in fetal renal development and impaired renal function, and may be associated with oligohydramnios and pulmonary hypoplasia. Congenital lower urinary tract obstructions may also result in bladder dysfunction, ultimately leading to a secondary functional obstruction that may require careful management to optimize renal outcomes.
