Urine specific gravity levels are expected to be ______ in infants with intrinsic renal failure.

• A. Low
• B. High
• C. Within Normal Limits
• D. Unreliable

Answer: (A)

Urine specific gravity shows how concentrated or dilute urine is, which depends on the kidney’s tubular ability to reabsorb water and the medullary concentrating gradient. In intrinsic renal failure, tubular and parenchymal damage disrupts this concentrating mechanism, so the kidneys can’t reclaim water effectively. The result is urine that remains dilute, yielding a low specific gravity. This is especially true in infants, whose concentrating ability is already immature, so tubular injury further reduces concentration and pushes SG toward isosthenic levels (roughly around 1.010–1.012). A high or normal SG would imply preserved concentrating function or a need to consider another cause, so the expected finding in intrinsic renal failure is a low urine specific gravity.