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NICU guideline identifier

Fluids - Fluid and Glucose requirements

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  Day 0-1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7+
<37 weeks 60 75 90 105 120 150 180
37 weeks+ 60 75 90 105 120 120 150
  • Fluid volumes administered in NICU after the first week are high to ensure good caloric intake and growth in preterm infants. Term infants have a lower requirement for fluids and calories.
  • Infants admitted to Starship Hospital (surgical or medical services) should have fluids prescribed according to Starship Hospital guidelines (available via the intranet).
  • The volume administered will depend on the clinical condition of the infant, with fluid restriction indicated with asphyxia, renal impairment or PDA.
  • Infants receiving phototherapy, or with high insensible losses, may require higher fluid intakes.
  • In general, fluid management in the first few days is adjusted primarily on serum sodium values and changes in weight.
    • High serum sodium values usually indicate that the infant requires more fluid.
    • Low serum sodium values may indicate that the infant requires less fluid, or that the infant has high sodium losses.
  • There is evidence that restricting fluid volumes in preterm infants in the first few days of life reduces the incidence of patent ductus arteriosus and necrotising enterocolitis, and may decrease mortality rates.1
  • Restricting sodium intake in preterm infants in the first few days may also reduce the incidence of chronic lung disease.2,3,4,5

Glucose intake

The neonatal liver normally produces 6-8 mg/kg/min of glucose. This is approximately the basal requirement of a newborn infant.

Hypoglycaemia is severe if it persists despite an intake of >10 mg/kg/min. Calculate the glucose intake: See also the Glucose Calculator

Glucose intake (mg/kg/min) =  % Glucose x Volume (ml/kg/day)

Glucose intake (mg/kg/min) = % Glucose x Hourly Rate
                                                      Weight (Kg) x 6

Intake  (ml/kg/day) 5% Glucose 10% Glucose 12.5% Glucose
  mg/kg/min of Glucose
60 2.1 4.2 5.2
75 2.6 5.2 6.5
90 3.1 6.3 7.8
105 3.7 7.3 9.1
120 4.2 8.3 10.4
150 5.2 10.4 13.0
180 6.3 12.5 15.6

To get concentrated glucose solutions: See also the Fluid and Electrolytes calculator

Solution 10% Glucose 50% Glucose
12.5% 450 ml 30 ml
15% 420 ml 60 ml
20% 400 ml 135 ml
Solution 5% Glucose 50% Glucose
7.5%   450 ml  30 ml

Glucose solutions of >10% are best administered through central venous lines. Peripheral IVs do not last long, and extravasation can result in tissue damage.

Insensible Water Loss

This varies greatly with gestation and depends on the thermal environment. It decreases markedly over the first few days. Very preterm infants should be placed in humidified incubators in a neutral thermal environment as soon as practical after birth.

Gastrointestinal Losses

If there are significant gastric aspirates, replace these ml for ml with 0.9% NaCl plus 10mmolKCl per 500ml.

Chest and/or Peritoneal Drains

  • If there are significant fluid losses from these, measure the volume and replace with 4% albumin as indicated.
  • Monitor serum albumin concentrations.
  • Monitor the composition of the fluid being lost as this may assist with calculating requirements

Renal Impairment

  • Restrict intake to insensible water loss + urine output.
  • Monitor fluid balance, serum electrolytes and weight carefully.
  • In early Acute Tubular Necrosis, consider a pre-renal cause. Fractional excretion of sodium may help sort this out.

    FE Na+≥2.5% in term infants suggests renal failure.
    FE Na+<2.5% in term infants suggests pre-renal failure.
    FE Na+ is high in preterm infants because of tubular immaturity.

    FE Na+ = Urine [Na] x Serum Creatinine
                    Serum [Na+] x Urine Creatinine              x 100%


  1. Bell EF, Acarregui MJ. Restricted versus liberal water intake for preventing morbidity and mortality in preterm infants. Cochrane Database of Systematic Reviews 2001, Issue 3. Art. No.: CD000503. DOI: 10.1002/14651858.CD000503. 
  2. Hartnoll G, Betremieux P, Modi N. Randomised controlled trial of postnatal sodium supplementation on oxygen dependency and body weight in 25-30 week gestational age infants. Arch Dis Child Fetal Neonatal Ed 2000;82(1):F19-23. 
  3. Hartnoll G, Betremieux P, Modi N. Randomised controlled trial of postnatal sodium supplementation on body composition in 25 to 30 week gestational age infants. Arch Dis Child Fetal Neonatal Ed 2000;82(1):F24-8. 
  4. Hartnoll G, Betremieux P, Modi N. Randomised controlled trial of postnatal sodium supplementation in infants of 25-30 weeks gestational age: effects on cardiopulmonary adaptation. Arch Dis Child Fetal Neonatal E. 2001;85(1):F29-32. 
  5. Costarino AT Jr, Gruskay JA, Corcoran L, Polin RA, Baumgart S. Sodium restriction versus daily maintenance replacement in very low birth weight premature neonates: a randomized, blind therapeutic trial. J Pediatr 1992;120(1):99-106.

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Document Control

  • Date last published: 31 January 2007
  • Document type: Clinical Guideline
  • Services responsible: Neonatology
  • Owner: Newborn Services Clinical Practice Committee
  • Editor: Sarah Bellhouse
  • Review frequency: 2 years