Use of acidified versus non-acidified liquid human milk fortifier in very low birth weight infants: A retrospective comparison of clinical outcomes.

Background: Use of human milk is recommended for low birth weight (VLBW) infants, but must be safety fortified with sterile liquid fortifiers to be nutritionally sufficient. Due to clinical concern for a high incidence of metabolic acidosis among VLBW infants fed human milk fortified with acidified liquid human milk fortifier (ALHMF), we aimed to retrospectively compare the outcomes of infants fed ALHMF to those fortified with non-acidified liquid HMF (NLHMF).

Methods: Medical records of VLBW neonates admitted to our institution's neonatal intensive care unit from July 1st, 2013 to June 30th, 2014 were reviewed. 129 patients were included in the study, 61 of which received ALHMF and 68 received NLHMF. Metabolic, nutritional and clinical outcomes, including growth, were compared between the two cohorts.

Results: Of the infants who received ALHMF, 70.5% developed metabolic acidosis compared to only 11.8% in the NLHMF group (p < 0.001). In addition, infants who received NLHMF had a 10% greater growth velocity during the period of fortification (p = 0.01). During the full course of hospitalization, no difference in growth velocity was seen between the groups and greater length gains were found in the ALHMF group.

Conclusions: The use of human milk fortified with ALHMF was associated with an increased incidence of metabolic acidosis and poorer growth during the period of fortification when compared to NLHMF-fortified feedings. These growth effects were not apparent when the duration of hospitalization was considered, suggesting a need for further study to better characterize the advantages and disadvantages of each fortifier.