Most common cause of urinary ascites -

Ans. is 'a' i.e., Post urethral valve o Forty percent of neonatal ascites is caused by urinary conditions. Urinary' ascites occurs when high intraluminal pressure forces urine to extravasate from the kidney, usually across a renal fornix. Urine then enters the retroperitoneum and travels across the peritoneum as a transudate. o If this urine or ascetic fluid is aspirated from the peritoneal cavity, the ascites or extravasated urine contains electrolyte and creatinine levels similar to those of serum. This is because the urine within the peritoneum is subject to the large absorptive mesothelial surface that quickly normalizes these values, masking the identity of ascitic fluid as urine. The diagnosis of urinary'- ascites may be difficult and may require definitive upper tract drainage in the form of nephrostomy tubes to establish the cause of the ascites and allow' its resolution, o Urinary ascites in the case of distal obstruction may serve to lower urinary pressures and offers some protection to the developing kidneys. "Posterior urethral valves are probably the most common underlying etiology" - Campbell's Urology