BACKGROUND: Preterm infants of <34 weeks gestation or <1500 g are at risk for postnatal growth failure and often require nutrition support after discharge. Despite expert recommendations for postdischarge human milk (HM) fortification or nutrient-enriched formula feeding, the effects of current feeding strategies on growth and HM intake remain unclear. This systematic review evaluated the impact of postdischarge fortified expressed HM or direct breastfeeding (BF) with postdischarge formula (PDF) bottle feeds compared to unfortified HM or BF with standard term formula bottle feeds on growth and HM intake outcomes through 6 and 12 months corrected age (CA). METHODS: A systematic search of eight databases and grey literature sources was conducted for studies published in English since 2012 identifying 3146 studies. Risk of bias was assessed using standardized Cochrane RoB 2 and ROBINS-I tools. Meta-analysis was not conducted due to heterogeneity in interventions, outcome timing, and outcome metrics; results were narratively synthesized. RESULTS: Four studies (n = 2 randomized controlled trials, n = 2 cohorts), including 548 preterm infants, met eligibility criteria. Two studies showed significantly greater weight gain, and one showed significantly greater head circumference in the fortified groups at 6 months CA compared to the unfortified groups. Length differences were not significant. Three studies reporting HM intake found comparable or greater HM intake in the fortified groups. CONCLUSION: Current evidence suggests that postdischarge fortified HM or direct BF with supplemental PDF bottle feeds may support improved weight and head circumference outcomes without compromising HM intake. However, methodological variability highlights the need for standardized, prospective studies.
Rebele et al. (2026) studied this question.