Which factor indicates potential fluid retention in preterm infants?

Decreased urine output in preterm infants is a significant indicator of potential fluid retention. In this patient population, various factors can lead to challenges in renal function and fluid balance. When urine output diminishes, it may suggest that the kidneys are struggling to excrete excess fluid or are unable to produce adequate urine due to immature renal function or physiological stressors.

Fluid retention can have serious implications for preterm infants, including increased risk for edema, hypertension, or even pulmonary complications as excess fluid can accumulate in the lungs. Monitoring urine output is therefore essential in managing and assessing the overall fluid status of these vulnerable infants to ensure they are neither dehydrated nor overloaded.

The other options do not indicate fluid retention directly: increased feeding could lead to better hydration and nutrient availability; concentrated urine typically signifies a state of dehydration rather than retention; and improved filtration refers to enhanced kidney function, which would not suggest fluid retention.