Which of the following may be a cause of postrenal failure in neonates?

• A. Acute Tubular Necrosis
• B. Congestive Heart Failure
• C. Prune Belly Syndrome
• D. Nephrosis

Answer: (C)

Postrenal failure in neonates comes from an obstruction to urine flow downstream of the kidneys. Prune belly syndrome can cause this kind of obstruction because it is often accompanied by urinary tract malformations and bladder outlet obstruction, such as a poorly compliant or obstructed bladder and dilated ureters. The resulting back pressure from the obstructed flow leads to hydronephrosis and impaired kidney function, which fits postrenal failure.

In contrast, acute tubular necrosis is an intrinsic kidney injury from ischemia or toxins, not an obstruction. Congestive heart failure mainly reduces renal perfusion (pre-renal) and can damage the kidneys secondarily, but it does not block urine outflow. Nephrosis is a glomerular disease causing protein loss rather than an obstruction to urine flow.