This prospective randomized controlled trial aims to investigate whether feeding very low birth weight (VLBW) infants with Mother's own milk (MOM) supplemented with either preterm (PDM) or term donor milk (TDM), when MOM is insufficient, has a positive impact on infants' protein intake, growth and morbidity.

Mother's own milk (MOM) is the optimal nutrition for preterm infants. When MOM is not sufficient, pasteurized donor milk (DM) is the best alternative according to current recommendations. Donor milk is primarily derived from mothers of term-born infants for the first six months of lactation. However, this term milk presents significant differences compared to preterm human milk which has higher protein concentration and more caloric energy.

The investigators hypothesized that feeding VLBW infants with preterm donor milk (PDM) in combination with MOM may positively influence the protein intake and, consequently, the infants' growth. The aim of the current study is to assess whether MOM supplementation with PDM has any beneficial effects on the nutrition, growth and morbidity in VLBW infants.

Inclusion Criteria:

• VLBW infants with birth weight <1500g born to mothers who agree to provide donor milk for the first three weeks of life (donor milk period) if their own milk quantity is insufficient

Exclusion Criteria:

• Congenital anomalies
• Chromosomal disorders
• Metabolic diseases
• Feeding with formula at any point during the first 3 weeks of life (donor milk period)