Infusion fluid volumes during the first day of life for a preterm infant weighing 1000-1500 grams should approximate:

• A. 60 to 100 mL/kg/day
• B. 100 to 120 mL/kg/day
• C. 120-140 mL/kg/day
• D. 140-160 mL/kg/day

Answer: (A)

In the first day of life for a preterm infant weighing about 1,000–1,500 g, the goal is to keep enough intravascular volume to maintain perfusion while avoiding fluid overload. The infant’s kidneys are immature and insensible losses are relatively high, so a conservative maintenance fluid intake is used. The commonly used range is 60 to 100 mL per kilogram per day. This lower-to-moderate volume helps prevent dehydration and electrolyte disturbances without pushing fluid load that could contribute to complications such as intraventricular hemorrhage, patent ductus arteriosus, or pulmonary edema that preterm infants are especially susceptible to.

As the infant stabilizes over the next days, fluid needs are reassessed and typically increased gradually toward higher maintenance levels as renal function matures and weight gain occurs, with close monitoring of urine output and electrolytes guiding adjustments.

Choosing volumes higher than this early range risks overload in a fragile preterm circulatory system, while volumes lower than this range raise the concern for dehydration and electrolyte imbalance.