NICU · Fluids
Neonatal Fluid Maintenance
Starting fluid range by birth weight category, day of life 1 through 7. Smaller, more preterm infants start higher due to greater insensible water loss.
Birth weight
kg
Day of life
Day 1
Total daily volume
—
- Rate
- —
- Category
- —
Progression this week, this weight category
| Day | mL/kg/day | Total (this weight) |
|---|
Why category matters
- <1000 g (ELBW)
- Highest insensible losses through thin, immature skin — starts highest, especially under a radiant warmer or phototherapy
- 1000–1500 g (VLBW)
- Similar pattern to ELBW, slightly lower starting point
- 1500–2500 g
- Lower insensible losses, more mature skin barrier
- >2500 g (term)
- Lowest starting fluids; expect ~5–10% weight loss in the first week as a normal diuresis
Clinical decision support only. These are commonly cited starting ranges — actual orders depend on your institution's protocol, the infant's environment (radiant warmer vs. humidified incubator, phototherapy), serum sodium, and urine output. Adjust based on daily weight change and labs, not on this range alone.