Feeding the Preterm Infant

Publication: 17/07/2007  --
Last review: 21/08/2018  
Next review: 21/08/2021  
Clinical Guideline
ID: 1139 
Approved By: Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2018  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Feeding the Preterm Infant

Guideline Summary




1251-1500g or <33/40

Stage 1 Trophic Feeds

Up to 10ml/kg/day of EBM for the first
48 Hours after birth

Up to 10ml/kg/day of EBM for the first
24 Hours after birth

Commence on Stage 2

Stage 2
Initial Nutritive Feed




Stage 3
24 Hourly Increments




The initial nutritive feed volume is 20ml/kg/day for the Red and Yellow groups, irrespective of the volume of trophic feeds achieved in Stage 1.

Feeds are initially given as 2 hourly bolus feeds in all stages.

Infants >1500g AND >32+6:
These infants may tolerate full enteral feeds from birth and should increase as tolerated following their daily fluid increments.

Infants in this group who are ‘unwell’ (for example requiring significant ventilatory support, inotropic support or infants with HIE) should be assessed on an individual basis. Commencing infants on Stage 1 trophic feeding has been shown to promote gut development along with added immunological benefits and consideration should be given to commencing Stage 1 feeding in these circumstances. Advancing to Stage 2 should be reviewed on a case by case basis.

Action with gastric residuals:
If aspirates 25-50% of total, replace the volume, omit the feed and do not increment.
If aspirates >50% of total, stop feeds and medical review.
If dark bilious rather than lightly bile stained, stop feeds and medical review.

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The aim of this guideline is to provide a standardised approach to initiating and advancing enteral feeds in preterm or growth restricted infants. There is some evidence that this in itself may reduce the risk of NEC.


The goal of nutrition is to achieve optimal growth. This can partly be provided by parenteral nutrition, however this has complications including cholestasis and risk of catheter related sepsis. The aim should therefore be to introduce enteral milk feeds as early as a baby can tolerate them. The main concerns around commencement and progression of enteral feeding are feed tolerance and the development of necrotising enterocolitis (NEC). The aetiology of NEC is multifactorial, but rapid increments in enteral feeding is a recognised risk factor in preterm infants. There is no universally agreed feeding guideline, but following a standardised method of initiating and advancing enteral feeds in preterm neonates reduces variation and may subsequently reduce the risk of NEC. This guideline has been developed using published evidence and information from other units and local expertise.

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Risk Groups and Nutritional Consideration

This guideline uses a risk factor approach. Increasing prematurity and growth restriction are risk factors for NEC, therefore weight is used to group babies according to risk. The weight bands of 250g have been designed so that any infant who suffers significant growth restriction to below the 2nd centile for their gestation will drop into a higher risk feeding regime.

Red Regime
Infants born <1001g
Yellow Regime
Infants born 1001-1250g
Green Regime
Infants born 1251-1500g OR born <33 weeks gestation

Infants born weighing greater than 1500g and who are over 32+6 weeks gestation may tolerate full enteral feeds. These infants should be commenced on a full initial feed volume and advanced as per their daily requirements.







Volume (ml/kg)






Abnormal Dopplers
Multiple studies have demonstrated that babies who have abnormal dopplers in utero are at a higher risk of developing NEC. However, as the principle impact of abnormal dopplers on the fetus is growth restriction and preterm labour, it is not possible to identify an abnormal doppler examination as an independent risk factor. The outcomes from the SIFT trial showed no increase in rates of NEC in babies with IUGR (birth weight <10th centile) when comparing 18ml/kg/day feed increments to 30ml/kg/day. In view of this, a baby’s birth weight will determine its feeding regime category.

Nutritional Consideration
Many of the most preterm, growth restricted infants will suffer postnatal growth restriction due to delayed feeding. This can be minimised with the use of parenteral nutrition. In accordance with BAPM guidance this should be commenced for all infants in the Red and Yellow Regimes. Parenteral nutrition should also be considered for infants in the Green Regime who are 29+6 weeks gestation or less and demonstrate a delay in feed tolerance (defined by not achieving an enteral feed volume of 100ml/kg/day by Day 5).

For infants on “full” enteral feeds, growth (weight and head circumference) should be monitored twice weekly and plotted on their growth chart.
18g/kg/day for <30 weeks
15g/kg/day for 30 weeks to Term
30g/day thereafter

For the majority of preterm infants, 165ml/kg/day of breast milk will not fulfill their nutritional requirements. Breast Milk Fortifier should be commenced according to the Nutritional Supplements Guideline.

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Commencing and Advancing Feeds

Commencing feeds
There is a limitation of evidence regarding the timing of initiation of any feed. Neonatal units with prolonged periods of enteral fasting have been shown to have the lowest rates of necrotising enterocolitis, however prolonged periods of parenteral nutrition brings with it the disadvantages of increased rates of catheter acquired infection and cholestasis. Cochrane reviews found that delaying enteral feeding beyond four days did not result in any lower rates of NEC or improved feed tolerance. There is limited evidence to guide the timing of commitment of enteral feeds within this four day period with relation to rates of NEC.

There is an increasing body of evidence relating the early initiation of enteral feeding in preterm or low birth weight infants and the rates of late onset sepsis. Babies who have feeds commenced early have been shown to have lower rates of infection both with coagulase negative staphylococcus and with fungal sepsis such as candida. This has been attributed both to fewer number of days with central venous catheters and with an immunological impact of enteral feeding.

Enteral feeds of colostrum or EBM can be commenced from birth in all risk groups, up to a volume of 10ml/kg/day in babies weighing less than 1251g. Due to the impact EBM has on gut priming and the potential immunological benefits, it should be given either enterally via the nasogastric tube, orally via an enteral syringe or as mouth care. If there is no colostrum or EBM available, there is no evidence that donor breast milk or formula carry similar benefits so these are not to be used as an alternative. These infants will go straight to Stage 2 nutritive feeds after the first 24 (Yellow Regime babies) or 48 hours (Red Regime babies).

Due to the benefits of commencing feeds early, if there is no EBM available by the time the baby reaches Stage 2 of their feeding regime, an alternative should be explored. Parents should be counselled regarding either donor breast milk or preterm formula (see section on donor breast milk for details on which babies qualify).

Use of umbilical venous catheters is not a contraindication to feeding. Infants with a umbilical arterial catheter can increase feeds unless on increasing doses of inotropes, but the ongoing need for a UAC needs to be reviewed daily.

Commencement of enteral feeds




1251-1500g or <33/40

Stage 1 Trophic Feeds

Up to 10ml/kg/day of EBM for 48 Hours

Up to 10ml/kg/day of EBM for 24 Hours

Commence on Stage 2

Trophic feeds can be given as 2 hourly bolus feeds.

Advancing feeds
Studies have shown conflicting results regarding optimal feeding strategies. Historical studies have demonstrated that infants with the fastest increments in feeds are more likely to develop NEC. Units reporting the lowest rates of NEC have very slow rates of feed increments and long periods on no feeding at all after birth, though the number of days to reach full feeds can be as much as 40 days and this needs to be balanced with the risks of prolonged use of parenteral nutrition and an increased number of days with central venous access.

Randomised controlled trials and Cochrane reviews comparing slow vs. faster rates of increments have shown that daily increments of up to 35ml/kg/day add no additional risks of developing NEC when compared to daily increases of just 15ml/kg/day. However, up until the recent results of the SIFT trial there remained very limited evidence of how these feeding regimes apply to extreme preterm or extremely low birth weight infants.

A large randomised control trial (SIFT) comparing feed increments of 18ml/kg/day with 30ml/kg/day demonstrated no increased rates of NEC or late onset sepsis in either group, even in babies born with extreme prematurity or IUGR (<10th centile). However, the day of commencement of feeds was not investigated or stipulated so the days of NBM prior to commencing feeds varied. 2 year neurodevelopmental follow-up of babies in the SIFT showed an unexpected trend towards worse outcomes in the babies fed at 30ml/kg/day, though the biological reasoning for this is unclear. In view of these results the feed increment in the higher risk groups is 20ml/kg/day, irrespective of the volumes babies have received during Stage 1. Babies in the Green group who would not routinely receive PN advance at 30ml/kg/day.

Feeds can be advanced if:
Gastric aspirates <25% of volume given since last residual check.
No bilious aspirate
No significant abdominal distension

Feeds should be given as 2 hourly bolus gravity feeds for both initiation and advancing enteral feeds. Arguments for continuous or more frequent feeding include quicker establishment of feeds, less energy demands for the baby to digest larger volumes at a time resulting in improved growth and improved nutrient absorption. However, multiple studies and a Cochrane review have not found any evidence to support this over bolus feeding. In fact continuous feeding resulted in longer to establish feeds with no differences in rates of NEC, feed tolerance or improvements in somatic growth parameters.




1251-1500g or <33/40

Stage 2
Initial Nutritive Feeds




Stage 3
24 Hourly Increments




Giving bolus feeds allows better establishment of beneficial intestinal hormones such as gastrin and enteroglucagon which encourage gut development and motility, as well as encouraging intestinal secretions.

Full enteral feeds can be commenced in well infants with a gestation greater than 32+6 and with a weight of 1551g or more. The volume will be as per local feed progression guidance.

Feeds should initially be given as 2 hourly bolus feeds

Infants receiving increasing doses of inotropes for hypotension may be at an increased risk of reduced gut perfusion. For this reason commencement and progression of enteral feeds should be avoided. However, if the infant has reached stability and inotropes are no longer being increased, a volume of up to 10ml/kg/day of maternal EBM can be considered. Mouth care with colostrum can continue irrespective of inotrope dose.

Gastric Aspirates
Feed intolerance has been determined in many ways based on the volume of milk aspirated from the gastric tube e.g. gastric residual volumes (GRV’s) >20% of preceding 3 hour volume, 2mL of undigested formula and 3mL/kg of feed. None of these definitions have been shown to be superior to another in a randomised controlled trial.

The nature of the aspirate is often commented on. In an observational study, green stained aspirates were of themselves not a marker of feed intolerance if of small volume (<2mL for infants <750g, or <3mL for infants <1kg). However, a dark stained gastric aspirate is generally accepted as abnormal when a feeding tube is believed to be correctly positioned in the stomach.
An appropriate GRV is <25% of preceding volume administered since last replacement of gastric aspirate. In this case, the aspirated volume should be replaced in full. A GRV of 25-50% of given volume is relatively high. If the infant is well and there is no clinical evidence of NEC, then the normal hourly volume should be replaced only. Feeds may be continued, but there should be no increments in feed until GRV has been below 25% on two consecutive occasions.

A GRV of greater than 50% of preceding volume administered is excessive and should prompt a clinical assessment. If the examination is unremarkable and the infant is well, the hourly amount should be replaced and the feed omitted. If the following aspirate before the next scheduled feed has reduced then feeds can be continued, but sustained aspirates of >50% should prompt further review and withholding feeds.

Lightly bile stained aspirates can be tolerated if of acceptable volume. Dark stained bile aspirates are abnormal and should lead to immediate cessation of feeds, clinical examination and assessment of position of NG tube in case of inadvertent advancement past the pylorus. An AXR should be ordered if there is any doubt.

In summary:

  • Aspirate NG tube every 4-6 hours dependent on cares
  • Bile
    • Dark bilious? If so then NBM, check NG position, clinical exam and consider AXR
    •  Light bile stained? Acceptable if volume aspirated OK
  • Volume
    • Less than 25% of volume given since last replacement of residual?
      • Replace entire amount and continue with feeds. Increment feeds if due
    • Volume 25-50% of volume given since last replacement of residual?
      • If well, replace aspirate only. Omit the feed and do not increment.
    • Volume >50% of volume given since last replacement of residual?
      • Empty the stomach and clinically assess for NEC.
      • If examination is normal and the baby is well, replace the hourly amount and re-check GRV before next feed. If reduced can consider continuing feeds.
      • If the GRVs are consistently >50% requires further clinical assessment and consider withholding feeds.

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Choice of Milk

Comparisons have been made between expressed breast milk (EBM), donor breast milk and preterm formula in randomised controlled trials. A recent meta-analysis based on 3 studies determined that donor breast milk (DBM) results in poorer weight gain than preterm formula. However, the relative risk of developing NEC was much lower in infants fed DBM with a RR of 0.21 (CI 0.06-0.76). In addition, donor breast milk enabled full enteral feeds to be attained faster than with preterm formula.

Maternal breast milk
Maternal breast milk is the milk of choice for all risk groups. If maternal milk becomes in short supply, it may be necessary to use an alternative see below.

Any transition from breast milk to formula milk ideally should be done as a graded introduction, and for infants in the Red and Yellow Regimes this should be done as below for transitioning from donor breast milk. In these infants if there is a significant shortage of maternal milk, donor milk may be needed to bridge the “gap” between maternal milk and formula while increasing slowly (ie the infant may be on a mixture of maternal breast milk, donor breast milk and preterm formula in each feed).

Donor breast milk
For infants in the Red and Yellow Regimes, donor breast milk is the second choice milk (with consent from parents). Infants in these groups are at the highest risk for NEC and therefore will gain most benefit from donor breast milk.

Once infants have established full enteral feeding and are 21 days of age, there should be a transition from donor breast milk to preterm formula. This is necessary as donor breast milk is of inferior nutritional quality compared with maternal breast milk and preterm formula. In addition, in many centres the cost implications of long term donor breast milk are large.

Transition to preterm formula should be done in a controlled manner as there are a number of case reports of fulminant NEC presenting in this period. The recommended transition is by 10% every 24 hours.

For infants in the Green Regime and those with no consent for donor breast milk, formula is the second choice milk. The decision between preterm and term formula depends upon the baby’s birth weight and gestation.
In Leeds we use SMA Gold Prem 1 as opposed to Nutriprem 1 due to the higher protein concentration (3.6g/100kcal vs 3.3g/100kcal). It is also a hydrolysed whey protein.





<34 weeks

>34 weeks

1st Choice





2nd Choice




Term Formula

3rd Choice







Term Formula

For nutritional supplementation such as Sytron, Abidec and Breast Milk Fortifier please refer to the Nutritional Supplementation Guideline.

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Record: 1139
Clinical condition:

Preterm Infant Nutrition

Target patient group: Premature Neonates (less than 37 weeks gestation)
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Adapted from:

Evidence base

References and Evidence levels:
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus.
D. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

Patole SK, de Klerk N. Impact of standardised feeding regimens on incidence of neonatal necrotising enterocolitis: a systematic review and meta-analysis of observational studies. Arch Dis Child Fetal Neonatal Ed. 2005 Mar;90(2):F147-51. Review

Pietz J, Achanti B, Lilien L et al. Prevention of necrotizing enterocolitis in preterm infants: a 20-year experience. Pediatrics. 2007 Jan;119(1):e164-70. Epub 2006 Dec 4

Patole S, McGlone L, Muller R. Virtual elimination of necrotising enterocolitis for 5 years - reasons? Med Hypotheses. 2003 Nov-Dec;61(5-6):617-22
Tyson JE, Kennedy KA. Trophic feedings for parenterally fed infants.

Cochrane Database Syst Rev. 2005 Jul 20;(3):CD000504. Review
Caple J, Armentrout D, Huseby V et al. Randomized, controlled trial of slow versus rapid feeding volume advancement in preterm infants. Pediatrics. 2004 Dec;114(6):1597-600

McClure RJ, Newell SJ. Randomised controlled study of clinical outcome following trophic feeding. Arch Dis Child Fetal Neonatal Ed. 2000 Jan;82(1):F29-33

Rayyis SF, Ambalavanan N, Wright L, Carlo WA. Randomized trial of "slow" versus "fast" feed advancements on the incidence of necrotizing enterocolitis in very low birth weight infants. J Pediatr. 1999 Mar;134(3):293-7

Kamitsuka MD, Horton MK, Williams MA. The incidence of necrotizing enterocolitis after introducing standardized feeding schedules for infants between 1250 and 2500 grams and less than 35 weeks of gestation. Pediatrics. 2000 Feb;105(2):379-84

Reynolds RM, Thureen PJ. Special circumstances: trophic feeds, necrotizing enterocolitis and bronchopulmonary dysplasia. Semin Fetal Neonatal Med. 2007 Feb;12(1):64-70. Epub 2006 Dec 26. Review

Cobb BA, Carlo WA, Ambalavanan N. Gastric residuals and their relationship to necrotizing enterocolitis in very low birth weight infants. Pediatrics. 2004 Jan;113(1 Pt 1):50-3

Mihatsch WA, von Schoenaich P, Fahnenstich H, et al. The significance of gastric residuals in the early enteral feeding advancement of extremely low birth weight infants. Pediatrics. 2002 Mar;109(3):457-9

Schanler RJ, Lau C, Hurst NM, Smith EO. Randomized trial of donor human milk versus preterm formula as substitutes for mothers' own milk in the feeding of extremely premature infants. Pediatrics. 2005 Aug;116(2):400-6

Boyd CA, Quigley MA, Brocklehurst P. Donor breast milk versus infant formula for preterm infants: a systematic review and meta-analysis. Arch Dis Child Fetal Neonatal Ed. 2006 Apr 5; [Epub ahead of print]

Bombell S, McGuire W. Early trophic feeding for very low birth weight infants. Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No.: CD000504. DOI: 10.1002/14651858.CD000504.pub3.

G Henderson, S Craig, P Brocklehurst, W McGuire. Enteral feeding regimens and necrotising enterocolitis in preterm infants: a multicentre case–control study. Arch Dis Child Fetal Neonatal Ed 2008;93:F162-F166

M Chauhan, G Henderson, W McGuire. Enteral feeding for very low birth weight infants: reducing the risk of necrotising enterocolitis. Arch Dis Child Fetal Neonatal Ed 2008;93:F162-F166

P. J. Hammond1, M. E. Flett, M. De La Hunt. Fulminant Necrotising Enterocolitis Immediately Following Change to Low Birth Weight Formula Feeds  Eur J Pediatr Surg 2008; 18(3): 185-187

Bombell S, McGuire W. Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD001970. DOI: 10.1002/14651858.CD001970.pub2.

McGuire W, Bombell S. Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD001241. DOI: 10.1002/14651858.CD001241.pub2.

Morgan j. et al, Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in VLBW infants (review). The Cochrane Library, 2014.

Morgan J. et al Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants (Review). The Cochrane Library, 2014.

Sisk et al. Early human milk feeding is associated with a lower risk of necrotizing enterocolitis in very low birth weight infants. Journal of Perinatology (2007) 27, 428–433.

Suha et al. Randomized trial of “slow” versus “fast” feed advancements on the incidence of necrotizing enterocolitis in very low birth weight infants. Journal of Paediatrics Volume 134, Issue 3, March 1999, Pages 293–297

Morgan et al. Early trophic feeding versus enteral fasting for very preterm or very low birth weight infants. the Cochrane Library 2013.

Flidel-Rimon et al. Early enteral feeding and nosocomial sepsis in very low birthweight infants. Arch Dis Child Fetal Neonatal Ed 2004;89:F289-F292.

Benjamin et al. Neonatal Candidiasis Among Extremely Low Birth Weight Infants: Risk Factors, Mortality Rates, and Neurodevelopmental Outcomes at 18 to 22 Months. PEDIATRICS Vol. 117 No. 1 January 1, 2006.

Senterre, T. Practice of enteral nutrition in very low birth weight and extremely low birth weight infants. [Review] World Review of Nutrition and Dietetics. 2014: 110; 201-214

Karagol B. et al. Randomized Controlled Trial of Slow vs Rapid Enteral Feeding Advancements on the Clinical Outcomes of Preterm Infants With Birth Weight 750-1250 g. Journal of parenteral and enteral nutrition. 2013: 37(2) 223-8

Rønnestad et al. Late-Onset Septicemia in a Norwegian National Cohort of Extremely Premature Infants Receiving Very Early Full Human Milk Feeding. PEDIATRICS Vol. 115 No. 3 March 1, 2005.

Leaf et al. Early or Delayed Enteral Feeding for Preterm Growth-Restricted Infants: A Randomized Trial. PEDIATRICS Vol. 129 No. 5 May 1, 2012.

Lavoie et al. Earlier initiation of enteral nutrition is associated with lower risk of late-onset bacteremia only in most mature very low birth weight infants. Journal of Perinatology (2009) 29, 448–454; doi:10.1038/jp.2009.8.

Dorling et al. Feeding growth restricted preterm infants with abnormal antenatal Doppler results. Arch Dis Child Fetal Neonatal Ed 2005;90:F359–F363

Kamoji et al. Antenatal umbilical Doppler abnormalities: an independent risk factor for early onset neonatal necrotizing enterocolitis in premature infants. Acta Paediatr. 2008 Mar;97(3):327-31.

The Provision of Parenteral Nutrition within Neonatal Services: A Framework for Practice - BAPM Guidance December 2015

Presentation of initial SIFT results, BAPM Annual Meeting, September 2016

Rövekamp-Abels et al Intermittent Bolus or Semicontinuous Feeding for Preterm Infants? J Pediatr Gastroenterol Nutr. 2015 Dec;61(6):659-64

Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500g
Cochrane database of systematic reviews (Online) · January 2003

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Clinical Guidelines Group

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