Enteral Feeding in Neonates 1. Introduction

• The goal of nutrition is to achieve as near to normal weight gain and growth as possible.

• Enteral feeding should be introduced as soon as possible. This means starting in the labor room itself for the well infant.

• Breast milk is the milk of choice. All mothers should be encourage to give breast milk to their newborn babies.

• The calorie requirement : Term infants � 110 kcal/kg/day Preterm infants � 120 – 140 kcal/kg/day. 2. Type of milk for newborn feeding

There are three choices: • Expressed breast milk • Normal infant formula • Preterm infant formula

2.1 Breast Milk Breast milk is preferred as studies have shown that babies on breast milk had low risk for NEC and have better development quotient.1

However EBM might not be adequate for the nutritional needs of the very preterm infant as it:.

• does not have enough calories to ensure optimal early growth at 20 kcal/30mls.1

• does not have enough sodium to compensate for the high renal sodium losses of the preterm infant.

• does not have enough calcium or phosphate which will predispose to osteopenia of prematurity.2

• deficient in vitamins and iron relative to the needs of a preterm infant. Human Milk Fortifier (HMF)

• It is recommended to add HMF to EBM in babies < than 32 weeks or < 1500 grams.

• HMF will give extra calories, vitamins, calcium and phosphate. • HMF should be added to EBM only when the baby is on feeding at >

140 mls/kg/day. • 1 sachet (25g) added to 100 mls of EBM increases its strength to 81

cal/100mls. 2.2 Infant Formula Infant formula should only be given if there is no supply of EBM. There are 2 types of infant formula: Preterm formula and Normal Term Formula.

• Preterm formula : for babies born < 32 weeks or < 1500 grams.

• Normal infant formula : for babies born > 31 weeks or > 1500 grams.

Composition of various milks

Cow’s milk

Standard formula

Preterm formula

Mature breastmilk

Carbohydrate (g/100ml)

4.6 7.5 8.6 7.4

Fat (g/100ml)

3.9 3.6 4.4 4.2

Protein (g/100ml)

3.4 1.5 2.0 1.1

Casein/ lactalbumin ratio

4:1 2:3 2:3 2:3

Calories /100ml 67 67 80 70

Na+ (mmol/L) 23 16 33 15

K+ (mmol/L) 40 65 33 64

Ca++ (mg%) 124 46 77 35

PO4 (mg %) 98 33 41 15

Fe++ (mg%) 0.05 0.8 0.67 0.08

3. Strategies of administering enteral feeding

3.1. Orogastric Route : Because neonates are obligate nose breathers nasogastric tube can obstruct the nasal passage and compromise the baby’s breathing. Thus orogastric route should be use for babies on tube feeding.. 3.2. Continuous vs. intermittent bolus feeding: Studies have shown that bolus fed babies tolerated their feeds better and gain weight faster.3 Babies on continuous feeding have been shown to take longer time to reach full feeding but there is no difference in days of discharge, somatic growth and incidence of NEC.4

3.3. Cup feeding : if baby is able to suckle and mother is not with the baby, cup feeding is preferable to bottle feeding to prevent nipple confusion (if breast feeding is intended as the final mode of feeding).

4. When to start milk? As soon as possible for the well term babies However in the very preterm infant there is a concern of increase risk of NEC if feeding is started too early. Studies have suggested that rapid increment in feeding has a higher risk for NEC than the time at which feeding was started.5 In the very preterm infant MINIMAL ENTERAL FEEDING (MEN) has been recommended. The principle behind this is to commence very low volume enteral feeds on day 1 to 3 of life (i.e. at 5 to 25 mls/kg/day ) for both EBM and formula milk. MEN enhances DNA gut synthesis hence promotes gastrointestinal growth. This approach allows earlier establishment of full enteral feeds and shorter hospital stays, without any concomitant increase in NEC. 6

> 32 weeks Well babies Start milk immediately

29 – 32 weeks Well babies IVD + slow increase enteral feed from day 1

< 29 weeks Use MEN approach. Start feed on day 2 or 3 at 1 mls 3 hourly with EBM

> 28 weeks Sick babies Feed when clinically appropriate with EBM

5. How much to increase?

• Generally rate of increment of enteral feeding is about 20 to 30 mls/kg/day.

• Well term babies should be given breast feed on demand. Milk requirements for babies on full enteral feed from birth:

Day 1 60 mls/kg/day

Day 2 – 3 90 mls/kg/day

Day 4 – 6 120 mls/kg/day

Day 7 onwards 150 mls/kg/day

Add 15% if the babies is under phototherapy

• In babies requiring IV fluids at birth: The rate of increment need to be individualized to that baby. Babies should be observed for feeding intolerance (vomit/large aspirate) and observe for any abdominal distention before increasing the feed.

6. What is the maximum volume?

• The target weight gain should be around 15g/kg/day (range 10-25g/kg/day).

Less than this suggests calories need increasing. More than this should raise the possibility of fluid overload particularly in babies with chronic lung disease.

Preterm infants • Increase feed accordingly to 180 to 200 mls/kg/day.

• If on EBM, when at 150 mls/kg/day � add HMF

Term infant

• Allow demand feeding

o Study by Kuschel et al, a randomised trial in babies born before 30

weeks comparing remaining at a final feed volume of 150 ml/kg/day (120 cal/kg/day) to advancing to 200 mls/kg/day. About half the 200 group had to be cut back (to a mean of 180 mls/kg/day) due to feed intolerance or fluid overload.7

o Infants that require high calories due to increase energy expenditure e.g. chronic lung disease, should consider adding polycose and MCT.

7. When to stop HMF or Preterm Formula?

Consider changing preterm to standard formula and stopping adding HMF to EBM when babies reach 1800 grams in weight.

8. Vitamin and mineral supplementation.

Vitamins: A premature infant’s daily breast milk/ breast milk substitute intake will not supply the daily vitamin requirement. Multivitamin can be commence after day 7 of life. Vitamin supplements at 0.5 mls daily to be continued for 3-4 months post discharge. Iron: Premature infants have been deprived of the intra uterine accumulation of iron and can become rapidly depleted of iron when active erythropoiesis resumes. Therefore babies born with a birth weight < 2000g should receive iron supplements. Iron is given at a dose of 3 mg/kg elemental iron per day. Ferric Ammonium Citrate (400mg/5mls) contains 86 mg/5 mls of elemental iron. Start on day 42. Continue until baby is 3-4 months post discharge or until review by doctor .

Special Cases

1. IUGR babies with reversed end-diastolic flows on antenatal Doppler: Studies have shown that these babies are at risk of NEC. Thus feeds should be introduced slowly and initially use only EBM.8, 9

2. Pregestamil : contain glucose, MCT and protein as casein hydrolysate. Used in malabsorptive state in infants e.g. Post surgery, biliary obstruction and disaccharide deficiency

References 1. Lucas A, Gore SM, Cole TJ et al. Multicentre trial on feeding low birthweight infants: effects of diet

on early growth. Arch Dis Child 1984; 59: 722-730.

2. Lyon AJ. McIntosh N. Calcium and phosphorus balance in extremely low birthweight infants in the first six weeks of life. Arch Dis Child 1984; 59: 1145-50

3. Schandler RJ, Shulman RJ, LauC, Smith EO, Heitkemper MM. Feeding strategies for premature infants: randomized trial of gastrointestinal priming and tube feeding method. Pediatrics 1999; 103:

492-493. 4. Premji S. & Chessel L. Continuous nasogastric milk feeding versus intermittent bolus milk feeding

for premature infants less than 1500 grams. Cochrane Database of Systematic Reviews. Issue 1, 2002

5. Anderson DM, Kliegman RM. The relationship of neonatal alimentation practices to the occurrence of endemic necrotizing enterocolitis. Am J Perinatol 1991; 8: 62-7.

6. Tyson JE, Kennedy KA. Minimal enteral nutrition to promote feeding tolerance and prevent morbidity in parenterally fed neonates (Cochrane Review). In: The Cochrane Library, Issue 1, 1999.

Oxford: Update Software. 7. Kuschel C, Evans N, Askie L, Bredermeyer S, Nash J, Polverino J. A Randomised trial of enteral

feeding volumes in infants born before 30 weeks. Arch Dis Child 8. McDonnell M, Serra-Serra V, Gaffney G, Redman CW, Hope PL. Neonatal outcome after

pregnancy complicated by abnormal velocity waveforms in the umbilical artery. Arch Dis Child 1994; 70: F84-9.

9. Malcolm G, Ellwood D, Devonald K, Beilby R, Henderson-Smart D. Absent or reversed end diastolic flow velocity in the umbilical artery and necrotising enterocolitis. Arch Dis Child 1991; 66:

805-7.