Background: Although donor milk is increasingly fed to preterm infants, the resultant quality of growth and body composition is unknown. The aim of this pilot study was to describe the body composition of very low-birth-weight infants fed human milk in the neonatal intensive care unit and explore the association between the proportion of donor human milk intake and fat-free and fat mass deposition. Methods: Body composition of 30 preterm infants fed maternal and donor human milk was measured by air displacement plethysmography. Regression models were developed to associate each parameter of body composition with the proportion of donor milk intake and other explanatory variables. Results: The proportion of donor milk intake was negatively associated with body fat percentage (P = .01). Fat-free mass z-scores ranged from −4.6 to 1.11 (mean z-score of −0.95, 17th percentile). Conclusion: Donor human milk intake is negatively associated with body fat percentage in this pilot study of very low-birth-weight preterm infants.

Protein content is often inadequate in donor breast milk (DBM), resulting in poor growth. The use of protein-enriched target-pooled DBM (DBM+) has not been examined. We compared three cohorts of very low birth weight (VLBW) infants, born ≤ 1500 g: DBM cohort receiving > 1-week target-pooled DBM (20 kcal/oz), MBM cohort receiving ≤ 1-week DBM, and DBM+ cohort receiving > 1-week DBM+. Infants followed a standardized feeding regimen with additional fortification per clinical discretion. Growth velocities and z-scores were calculated for the first 4 weeks (n = 69 for DBM, 71 for MBM, 70 for DBM+) and at 36 weeks post-menstrual age (n = 58, 64, 59, respectively). In total, 60.8% MBM infants received fortification >24 kcal/oz in the first 30 days vs. 78.3% DBM and 77.1% DBM+. Adjusting for SGA, length velocity was greater with DBM+ than DBM in week 1. Average weight velocity and z-score change were improved with MBM compared to DBM and DBM+, but length z-score decreased similarly across all groups. Incidences of NEC and feeding intolerance were unchanged between eras. Thus, baseline protein enrichment appears safe in stable VLBW infants. Weight gain is greatest with MBM. Linear growth comparable to MBM is achievable with DBM+, though the overall length trajectory remains suboptimal.