Background: The use of human milk for premature infants is increasing, partially because nutrient fortification ensures the attainment of intrauterine mineral accretion rates.

Hypothesis: Growth of premature infants fed fortified human milk(FHM) is similar to that of infants fed preterm formula (PF).

Subjects: Healthy, premature infants fed either FHM (n=41) or PF(n=42) in hospital.

Methods: Growth and 72-h nutrient balance measured at 6 & 9 wk.

Results: FHM and PF had similar birth weight (1.02±0.19 vs 1.07±0.17 kg, mean±SD), gestational age (28 ± 1 wk each), birth length and head circumference, and age at discharge (73 ± 20 vs 78 ± 21 d). Significant differences (p<0.01) between FHM and PF were observed for increments in weight (18±4 vs 22±4 g/kg/d), length (0.8±0.3 vs 1.0±0.2 cm/wk), and average skinfold thicknesses (0.17±0.08 vs 0.25±0.09 mm/wk). FHM had significantly (p<0.01) greater milk intake (182±11 vs 156±10 ml/kg/d) and greater intakes of protein, energy, calcium, and copper, lower intake of magnesium, and similar intakes of fat, zinc, and phosphorus compared with PF. FHM had significantly lower absorption of fat(62±16 vs 91±6%) and energy (82±6 vs 92±4%) but greater absorption of phosphorus, zinc, and copper compared with PF,p<0.01. At 9 wk, fat absorption (78±15 vs 92±7%) and energy absorption (87±5 vs 93±4%) increased, but remained lower in FHM than PF, p<0.01.

Conclusions: Fat absorption may be affected by nutrient fortification of human milk. The benefits of improved mineral status vs slower growth need to be determined.