Macronutrient analysis of target-pooled donor breast milk and corresponding growth in very low birth weight infants

Abstract

The macronutrient composition of target-pooled donor breast milk (DBM) (milk combined strategically to provide 20 kcal/oz) and growth patterns of preterm infants receiving it have not been characterized. Caloric target-pooled DBM samples were analyzed by near-infrared spectroscopy. Weekly growth velocities and anthropometric z-scores were calculated for the first 30 days and at 36 weeks corrected gestational age (CGA) for 69 very low birthweight (VLBW) infants receiving minimum one week of DBM. Samples contained mean 18.70 kcal/oz, 0.91 g/dL protein, 3.11 g/dL fat, 7.71 g/dL carbohydrate (n = 96), less than labeled values by 2.43 kcal/oz and 0.11 g/dL protein (p < 0.001). By week 3, growth reached 16.58 g/kg/day, 0.95 cm/week (length), and 1.01 cm/week (head circumference). Infants receiving <50% vs. >50% DBM had similar growth, but infants receiving >50% DBM were more likely to receive fortification >24 kcal/oz (83% vs. 51.9% in the <50% DBM group; p = 0.005). From birth to 36 weeks CGA (n = 60), there was a negative z-score change across all parameters with the greatest in length (−1.01). Thus, target-pooling does not meet recommended protein intake for VLBW infants. Infants fed target-pooled DBM still demonstrate a disproportionate negative change in length z-score over time.