Supplementation with human milk protein improves growth of small premature infants fed human milk. Randomized outcome trial of human milk fortification and developmental outcome in preterm infants. Improved bone mineralization and growth in premature infants fed fortified own mother's milk.
We investigated the influence of human milk protein and medium-chain triglyceride supplementations of human milk feedings on the growth of very low birth weight infants during their first weeks of life. A group of 44 preterm infants with birth weights of less than 1,520 g and a mean gestational age of 30.3 weeks was randomly divided into four groups to receive plain human milk or human milk supplemented with human milk protein (0.9 g/dL), with medium-chain triglycerides (1 g/dL), or with both. The medium-chain triglyceride oil supplementation did not influence the growth of these infants. The infants given supplementary protein gained weight faster during weeks 4 to 6 than those without (18.5 +/- 0.7 v 15.1 +/- 0.6 g/kg/d; mean +/- SEM; P = .001). After 4 weeks of age the infants given supplementary protein had a mean weight gain equal to the mean intrauterine rate, in contrast to the infants of the other groups, who grew more slowly until age 6 weeks. Furthermore, we found a correlation between serum albumin concentration and weight gain during the seventh week of life (P = .018). The length growth velocity for the infants with protein supplementation was 0.99 +/- 0.06 cm/wk (mean +/- SEM) and for those without 0.83 +/- 0.05 cm/wk (P = .043). There was no difference in growth of head circumference between the groups. We conclude that human milk protein supplementation improves the growth of small premature infants fed human milk, and that the protein concentration of bank milk is insufficient for their adequate growth. Despite potential benefits, human milk may fail to meet preterm infants' nutrient requirements. We tested the hypothesis that fortified breast milk, fed alone or with preterm formula, would improve neurodevelopment and growth at 18-mo follow-up without adverse short-term clinical or biochemical consequences. Two hundred seventy-five preterm infants from two medical centers (birth weight < 1850 g; mean gestation 29.8 +/- 2.7 wk) whose mothers chose to provide breast milk were randomly assigned to receive for a mean of 39 d a multinutrient fortifier or control supplement containing phosphate and vitamins. Breast milk comprised 47.6% and 46.4% of enteral intake in fortified and control groups, respectively; preterm formula supplements were used when insufficient breast milk was available. Overall, there were no significant growth advantages with fortification; although, when breast milk exceeded 50% of intake, fortification promoted faster weight gain (an advantage of 1.6 g.kg-1.d-1; 95% CI: 0.1, 3.1; P < 0.05). Compared with control infants, the fortified group showed 1) higher plasma urea from week 2 (P = 0.04), 2) higher plasma calcium (mean 2.34 +/- 0.01 compared with 2.27 +/- 0.02 mmol/L; P = 0.003), 3) a greater rise in alkaline phosphatase by week 6 (P = 0.04), 4) more clinical infections (suspected plus proven; 43% compared with 31%, P = 0.04), 5) a nonsignificantly increased incidence of necrotizing enterocolitis (5.8% compared with 2.2%, P = 0.12), and 6) higher white cell and platelet counts. Developmental scores at 18 mo were slightly but not significantly higher in the fortified group. This study confirmed that breast milk fortifiers can improve short-term growth (when breast milk intakes are high); but beneficial effects on long-term development remained unproven. Future research is required to evaluate potential adverse consequences and explore more optimal fortification strategies. "Preterm" human milk fortified with protein (0.85 gm/dL), calcium (90 mg/dL), and phosphorus (45 mg/dL) was compared with unfortified preterm human milk as a feeding for low birth weight infants. Additionally, a special formula for low birth weight infants (Similac Special Care (SC), 20 cal/oz), was compared with a standard 20 cal/oz formula (Similac). Bone mineral content (BMC), as measured by photon absorptiometry, improved in the study groups fed fortified human milk and Similac SC formula during the first 6 weeks of full oral feedings. Even though the intakes of calcium in the groups fed fortified human milk and Similac SC formula approached the intrauterine requirement for Ca during the third trimester of pregnancy (150 mg/kg/d), the values for BMC in these two groups (37 to 39 mg/cm) at the completion of the study were still considerably less than the intrauterine values for radial BMC at 36 to 37 weeks gestational age (72.6 +/- 14.1 mg/cm). Furthermore, the relative phosphorus deficiency (as determined by increased urinary Ca excretion and increased renal tubular reabsorption of phosphate) in the human milk groups occurred with or without supplements of Ca and P. Rate of weight gain in the fortified human milk group was greater than that of the unfortified human milk group and was comparable to that of infants fed Similac SC formula. Rate of weight gain for the unfortified human milk group was similar to that of infants fed Similac formula containing 20 cal/oz. However, none of the four feeding groups exceeded the 50th percentile for weight at the time of discharge (36 to 37 weeks postconceptional age). The results suggest that fortifying preterm human milk with Ca, P, and protein for low birth weight infants will improve bone mineralization and rate of growth to levels comparable to those achieved with a special formula containing high amounts of protein, Ca, and P.
Protein supplementation of human milk in relatively well preterm infants results in increases in short term weight gain, linear and head growth. Urea levels are increased, which may reflect adequate rather than excessive dietary protein intake. Further research should be directed towards the evaluation of specific levels of protein intake in preterm infants and the clinical effects of supplementation with protein, including long term growth and neurodevelopmental outcomes. This may best be done in the context of refinement of available multicomponent fortifier preparations.