LAUSR

Objectives Quantify associations of human milk feeding with in-hospital growth and examine differences by human milk type (maternal or donor). Study design We included infants born <33 weeks’ gestation and <1500 g from 9 Neonatal Intensive Care Units ( n  = 1429). We estimated associations of percent of visit days fed any human milk (maternal or donor) and percent of days fed donor milk with weight, length, and head z -scores at discharge or transfer using a linear mixed model, adjusting for birth size and other covariates. Results Any human milk feeding was not associated with growth outcomes. Infants fed donor milk on ≥50% of days had less favorable growth vs. those fed <50% [ z -scores—weight: −1.1 vs. −0.7 ( p  = 0.04); length: −1.5 vs. −1.1 ( p  = 0.04); head −1.0 vs. −0.3 ( p  < 0.01)]. Conclusions Fortified human milk was not associated with impaired growth compared with preterm formula.