This is a double-blind, randomized, multi-center, controlled, parallel study to evaluate the growth and tolerance of preterm infants fed human milk fortifier (HMF).

Inclusion Criteria:

• Birth weight between 700 g-1500 g.
• ≤ 32 weeks and 0 days GA at birth.
• Participant has been classified as appropriate for GA (AGA).
• Enteral feeding of human milk must be initiated by 21 days of life (birth date is day of life 0)
• Mother agrees to provide human milk as the exclusive feeding during the study period; use of donor milk is permitted if fortified with study fortifier and use of mother's own milk (when available) is prioritized.
• Parent(s) agrees to allow infant to receive both human milk and study HMF.
• Singleton or twin births only.
• Infant's parent(s) or a LAR has voluntarily signed and dated an ICF, approved by an IRB/IEC and provided HIPAA (or other applicable privacy regulation) authorization prior to any participation in the study.

Exclusion Criteria:

• Enteral feeding of preterm infant formula or HMF for > 7 days.
• Expected to be transferred to another facility within 30 days of randomization.
• Serious congenital abnormalities or underlying disease that may affect growth and development.
• 5-minute APGAR ≤ 4.
• Receiving systemic steroids at time of randomization.
• Receiving probiotics at time of randomization.
• Grade Ill or IV PVH/IVH.
• Dependent on invasive ventilation at time of randomization.
• Maternal incapacity.
• Mother or infant is currently receiving treatment consistent with HIV therapy.
• Documentation of maternal use of alcohol or marijuana during pregnancy that in the opinion of the physician is considered abuse.
• Positive toxicology report for cocaine, opiates, or methamphetamine in mother or infant.
• Infant has a history of major surgery (intra-thoracic or intra-abdominal procedures or other surgery requiring general anesthesia).
• Asphyxia defined as progressive hypoxemia and hypercapnia with significant metabolic acidemia characterized by APGAR score <3 at 10 minutes, seizures within the first 12 hours of life, or a cord blood gas < 7.0 and seizures and/or severe tonic abnormalities in the first 12 hours of life.
• Confirmed NEC (Bell's Stage II or III).
• Confirmed current sepsis.
• Infant has any other condition that, in the opinion of the investigator, precludes participation in the study.
• Participation in another study that has not been approved as a concomitant study by AN.
• Participant has an allergy or intolerance to any ingredient in study fortifier.