636 - Increased Pasteurized Donor Breastmilk Use in Preterm Infants Across 5 Neonatal Intensive Care Units in the New England Area and Its Effects on Growth

Publication Number: 636.5454

Joseph H. Chou, Harvard Medical School & Mass General Brigham, Boston, MA, United States; Jonathan A. Berken, The Children's Hospital of Philadelphia, Philadelphia, PA, United States; Juan D. Matute, University of Pennsylvania & Children's Hospital of Philadelphia, Philadelphia, PA, United States

Background: Human milk provides significant benefits for preterm newborns in Neonatal Intensive Care Units (NICU), including reduced risk of necrotizing enterocolitis. Pasteurized donor human milk (PDHM) is used in NICUs to meet the nutritional needs of infants when birthing parent’s own milk (POM) is insufficient. However, randomized clinical trials have shown that exclusive PDHM is associated with poorer growth outcomes than formula.

Objective: To compare the effectiveness of PDHM, POM, and formula, based on their nominal caloric densities, in supporting daily weight gain in preterm newborns and to examine the impact of PDHM on growth outcomes.

Design/Methods: From 2,429 newborns born before 34 weeks’ gestation between 2017 and 2024, 37,260 daily weights and enteral intake of PDHM, POM, and formula were used to develop a multivariable linear regression model for daily weight change. Changes in weight Z-score from birth to discharge were used to evaluate growth outcomes during 2,534 birth hospitalizations.

Results: We found increased use of PDHM between 2017 and 2024 (Fig. 1). The regression model for daily growth based on nominal caloric density showed that PDHM supported daily weight gain at 78% of POM effectiveness (P < 0.001) and formula at 112% (P < 0.001) (Table 1). PDHM was predominantly administered during the first two weeks after birth, but birth after 2020 was associated with more frequent and prolonged PDHM use over 160 cc/kg/day.

The association between PDHM administration and growth outcomes during 2,534 preterm birth hospitalization was also analyzed (Fig. 2). 80% of infants exposed to PDHM received 25 mL/kg/day or less of PDHM averaged across their birth hospitalizations. In this group, growth to discharge was higher than in infants without PDHM (Fig. 2). However, infants receiving PDHM above 25 mL/kg/day during their birth hospitalization showed decreased growth compared to those that did not receive PDHM, which worsened with higher average daily volumes of PDHM.

Conclusion(s): We confirmed that despite its lower intrinsic ability to support daily growth, PDHM with unknown caloric content can support adequate growth in most preterm infants with fortification. However, some infants may not achieve optimal growth when higher volumes of PDHM without known caloric content are used, as observed in randomized clinical trials. These findings underscore the need for close monitoring of growth in infants on PDHM, knowing the nutritional content of lots of donor breastmilk to optimize their use, and supporting birthing parents in providing their own milk, using PDHM as a bridge toward POM.

Table 1. Regression model to predict g/kg/day weight change by enteral feed type.
Multivariable regression for dependent variable g/kg/day daily weight change; independent variables kcal/kg/day for each of PDHM, POM, and formula; PMA relative to 29 weeks and weight Z-score at time of measurement; infant sex.

Figure 1. Average daily PDHM during hospital stay by date of birth.
Grey band represents the standard error of the mean around the blue linear regression line across all individual patients; black points show the average daily PDHM intake across all patients in a given birth year.

Figure 2. Effect of PDHM intake on growth outcome during the birth hospitalization.
Blue line is the smoothed conditional mean ∆Z weight versus PDHM intake, with the grey band representing the standard error of the mean; dashed red line represents the baseline mean ∆Z –0.66 with no PDHM.