Human milk fortification in preterm infants: Navigating evidence, practice, and controversy

Human milk is universally recognized as the optimal source of nutrition for preterm infants, providing immunologic, bioactive, and enzymatic components that provide health benefits and are associated with decreased morbidities of prematurity. However, fortification of both maternal breast milk (MBM) and donor breast milk (DBM) is needed to meet the elevated metabolic needs and nutrient requirements of preterm infants. This narrative review, reflecting the content presented, audience questions, and the roundtable discussion from the 2025 Neonatal Insights Conference, synthesizes current evidence and literature to evaluate the rationale, composition, and outcomes associated with differing fortification approaches. Randomized controlled trials evaluating fortifier type remain limited to small studies with high MBM usage. Future research must focus on trials evaluating fortifier type in infants who receive MBM and those that receive primarily DBM. Advancing fortification practices requires individualized nutrition planning and maternal breastfeeding support to achieve optimal growth and developmental trajectories for preterm infants.