Final answer:
Preterm infants commonly experience a decreased glomerular filtration rate, indicating acute renal failure and an immature renal system, which requires careful management to ensure adequate hydration.
Step-by-step explanation:
A nurse caring for preterm infants must be aware that their renal system is still immature and may not function as efficiently as that of full-term infants. One of the common renal complications observed in preterm infants is decreased glomerular filtration rate (GFR). This condition is indicative of acute renal failure, which is a rapid loss of renal function characterized by oliguria, an indicator of inefficient kidney activity. Preterm infants often present with a markedly reduced ability to concentrate urine, resulting in the production of very dilute urine. This underscores the need for adequate hydration through breast milk or formula to prevent further renal compromise.