Donor Human Milk Implementation in a High-Mother’s-Own-Milk NICU: Impact on Feeding Progression and Clinical Outcomes in Extremely Low Birth Weight Infants

Background: Donor human milk (DHM) is recommended when the mother’s own milk (MOM) is unavailable for extremely low birth weight (ELBW) infants. However, the impact of DHM implementation on NICUs with already high human milk utilization remains incompletely characterized. Objective: We aimed to evaluate the association between DHM implementation and feeding practices, feeding progression, parenteral nutrition (PN) exposure, and major neonatal morbidities in ELBW infants. Methods: We conducted a retrospective before–after cohort study in a single tertiary NICU including 116 ELBW infants with feeding data through day 28 (58 pre-DHM; 58 post-DHM). Exploratory multivariable models evaluated factors associated with NEC and PN duration. Results: In the post-DHM epoch, enteral feeding was initiated earlier (2 vs. 2.5 days, p < 0.001) and full enteral feeding was achieved sooner (14 vs. 24.5 days, p < 0.001). PN duration was numerically shorter (17.5 vs. 27 days, p = 0.088). Feeding shifted from predominantly exclusive MOM to mixed MOM + DHM regimens, eliminating formula-only feeding. NEC, feeding intolerance, bloodstream infection, and mortality did not differ between epochs. Feeding intolerance was associated with NEC, whereas lower gestational age predicted longer PN duration; epoch was not independently associated with either outcome. Conclusions: In this high-MOM NICU, DHM implementation was associated mainly with earlier feeding progression and reduced formula reliance, without a measurable reduction in NEC.