Iowa Neonatology Handbook: Feeding

Guidelines for the Use of Human Milk Fortifier in the Neonatal Intensive Care Unit

Susan Carlson RD, CSP, LD, Beth Wojcik RD, LD, and Jonathan Klein MD - 01/09/07
Peer Review Status: Internally Peer Reviewed

Background:

Fortification of Human Milk is indicated for preterm infants to meet protein and mineral requirements for growth. Current practice in our NICU is to begin HMF when the infant tolerates feeds of 50 to 80 cc/kg/d. Data collected on VLBW infants admitted to the UIHC NICU in 2004 demonstrated that unfortified human milk is used for a period of 2 -3 weeks before fortification is initiated.

During the period of time that infants receive unfortified breast milk, they accrue a mineral deficit. Protein intake may also be limited particularly when unfortified breast milk comprises >50% of total fluid intake. These deficits are particularly of concern in the smallest infants (<1000 g) who have higher protein and mineral needs for growth. Studies have shown that the addition of human milk fortifier is associated with short-term improvements in weight, length, and head circumference growth. Other studies suggest human milk fortifier may improve bone mineralization and neurologic outcome. (1-4)

The addition of human milk fortifier is well tolerated. An early study by Lucas et al showed an increase in infections (43% versus 31%) and NEC (5.8% versus 2.2%) in infants fed fortified versus unfortified human milk, however the infants in the study received >50% of their feeds from formula (5). Other studies with human milk fortifiers showed an increase in osmolality of the breast milk feeding after initiation of the supplement (6). Recent changes in fortifier composition have minimized this effect by adding fat and reducing the carbohydrate content of the supplement.

The addition of human milk fortifier appears to have no effect on the IgA content of human milk or on the concentrations of natural killer cell subsets in preterm infants fed the fortified milk (6,7). While the addition of human milk fortifier may temporarily delay gastric emptying and cause a short tem increase in gastric residuals and emesis, it is not associated with an increase in number of held feedings, incidence of blood in stools, incidence in apnea and bradycardia, or a delay in advancement to full enteral feeds (8-10).

Guidelines for the Use of Human Milk Fortifier:

1. Human Milk Fortifier (24 kcal/oz) is indicated for all breast milk fed infants weighing less than 2000 g.

2. Human Milk Fortifier (24 kcal/oz) should be initiated when the infant is tolerating breast milk feeds of > 25 ml/day.

3. Infants who have shown tolerance to breast milk + HMF feeds and were then made NPO should be restarted on breast milk + HMF feeds.

4. Concentrated breast milk feeds (27 kcal/oz or 30 kcal/oz) should only be used in infants who are already tolerating full feeds with HMF (24 kcal/oz), are no longer on NVN and meet one of the following criteria:

• Need for fluid restriction for BPD< 140 ml/kg.
• Poor weight gain (<10-15 g/kg/d) on 120 kcal/kg of 24 kcal/oz Breast Milk + HMF
• Metabolic bone disease (alkaline phosphatase > 600 U/L) with poor bone mineralization on x-ray requiring increased intakes of calcium and phosphorus

5. Infants >3000 g who require concentrated breast milk feeds should receive breast milk mixed with Term Formula Concentrate.

6. Infants on breast milk concentrated with HMF (27 kcal/oz or 30 kcal/oz) who develop hypercalcemia (ionized calcium > 6.5 mg/dl) or hyperphosphatemia (phosphorus > 7.5 mg/dl) should be switched to term formula concentrate to reduce excess mineral intake and receive a Nutrition Consult.

Monitoring Guidelines for Infants on Breast Milk + HMF

Preterm infants fed breast milk + HMF are at risk for hyponatremia due to the limited sodium content of these feeds and increased urinary sodium losses. Infants fed concentrated breast milk feeds (> 27 kcal/oz) are at risk for hypercalcemia and hyperphosphatemia secondary to the increased mineral content of these feeds.

24 kcal/oz Breast Milk + HMF

• Check electrolytes weekly until the electrolytes are stable (within normal limits) and the patient is no longer receiving IV fluids or oral electrolyte supplements.

27 kcal/oz Breast Milk + HMF

• Check electrolytes weekly until the electrolytes are stable (within normal limits) and the patient is no longer receiving IV fluids or oral electrolyte supplements.
• Check ionized calcium and phosphorus weekly while patient is on concentrated breast milk + HMF. Contact NICU RD if ionized calcium is > 6.5 mg/dl or phosphorus is > 7.5 mg/dl for recommendations to reduce mineral intake with the use of term formula concentrate.

30 kcal/oz Breast Milk + HMF

• Check electrolytes weekly until the electrolytes are stable (within normal limits) and the patient is no longer receiving IV fluids or oral electrolyte supplements.
• Check ionized calcium and phosphorus weekly while the patient is on concentrated breast milk + HMF. Contact NICU RD if ionized calcium is > 6.5 mg/dl or phosphorus is > 7.5 mg/dl for recommendations to reduce mineral intake with the use of term formula concentrate.

References:

1. Faerk J, Petersen S, Peitersen B, Michaelsen KF. Diet and bone mineral content at term in premature infants. Pediatr Res. 2000 Jan;47(1):148-56.
2. Gross SJ. Bone mineralization in preterm infants fed human milk with and without mineral supplementation. J Pediatr. 1987 Sep;111(3):450-8.
3. Nicholl RM, Gamsu HR. Changes in growth and metabolism in very low birthweight infants fed with fortified breast milk. Acta Paediatr. 1999 Oct;88(10):1056-61.
4. Pettifor JM, Rajah R, Venter A, Moodley GP, Opperman L, Cavaleros M, Ross FP. Bone mineralization and mineral homeostasis in very low-birth-weight infants fed either human milk or fortified human milk. J Pediatr Gastroenterol Nutr. 1989 Feb;8(2):217-24.
5. Lucas A, Fewtrell MS, Morley R, Lucas PJ, Baker BA, Lister G, Bishop NJ. Randomized outcome trial of human milk fortification and developmental outcome in preterm infants. Am J Clin Nutr. 1996 Aug;64(2):142-51.
6. Jocson MA, Mason EO, Schanler RJ. The effects of nutrient fortification and varying storage conditions on host defense properties of human milk. Pediatrics. 1997 Aug;100(2 Pt 1):240-3.
7. Tarcan A, Gurakan B, Tiker F, Ozbek N. Influence of feeding formula and breast milk fortifier on lymphocyte subsets in very low birth weight premature newborns. Biol Neonate. 2004;86(1):22-8. Epub 2004 Feb 20.
8. Ewer AK, Yu VY. Gastric emptying in pre-term infants: the effect of breast milk fortifier. Acta Paediatr. 1996 Sep;85(9):1112-5.
9. McClure RJ, Newell SJ. Effect of fortifying breast milk on gastric emptying. Arch Dis Child Fetal Neonatal Ed. 1996 Jan;74(1):F60-2.
10. Moody GJ, Schanler RJ, Lau C, Shulman RJ. Feeding tolerance in premature infants fed fortified human milk. J Pediatr Gastroenterol Nutr. 2000 Apr;30(4):408-12.

Recipes for Fortified Human Milk - Hospital Use:

Breast Milk + Human Milk Fortifier for Preterm Infants

24 kcal/oz Breast Milk + HMF

25 mL breast milk
1 packet Human Milk Fortifier

27 kcal/oz Breast Milk + HMF

100 mL breast milk
7 packets Human Milk Fortifier

30 kcal/oz Breast Milk + HMF

100 mL breast milk
7 packets Human Milk Fortifier
30 mL Term Formula Concentrate

Reduced Calcium / Phosphorus Breast Milk + HMF

27 kcal/oz Reduced Mineral Breast Milk + HMF

100 mL breast milk
5 packets Human Milk Fortifier
20 mL Term Formula Concentrate

30 kcal/oz Reduced Mineral Breast Milk + HMF

100 mL breast milk
5 packets Human Milk Fortifier
50 mL Term Formula Concentrate

Concentrated Breast Milk Feeds for Term Infants

24 kcal/oz Breast Milk

100 mL Breast Milk
25 mL Term Formula Concentrate

27 kcal/oz Breast Milk

100 mL Breast Milk
50 mL Term Formula Concentrate

30 kcal/oz Breast Milk

50 mL Breast Milk
50 mL Term Formula Concentrate

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