449 - Growth, Zinc Deficiency and Mortality to Discharge after Implementing a Donor Breast Milk (DBM) Program in Neonates <33 weeks Gestational Age (GA) or Birthweight <1500 grams

Poster Number: 449
Publication Number: 449.335

Mariela O. Sanchez Rosado, University of Texas Southwestern Medical School, Dallas, TX, United States; Audrey Edwards, Parkland Health and Hospital System, Plano, TX, United States; Theresa Jacob, Parkland Health and Hospital System, Dallas, TX, United States; Cheryl Lair, Parkland Health & Hospital System, Arlington, TX, United States; Larry S. Brown, Parkland Health & Hospital System, Dallas, TX, United States; Roy Heyne, UT Southwestern: The University of Texas Southwestern Medical Center, Dallas, TX, United States; David Nelson, University of Texas Southwestern Medical School, DALLAS, TX, United States; Luc P. Brion, University of Texas Southwestern Medical School, Dallas, TX, United States

Background: Breast milk (BM) including DBM is recommended for feeding preterm infants. DBM has been associated with less growth than formula. The amount of zinc (Zn) in DBM is lower than in milk of women delivering prematurely and is insufficient to support growth in preterm infants. Zn supplementation in preterm infants has been shown to improve weight gain and may improve linear growth and decrease mortality (Straub 2021).

Objective: To compare the frequency of poor growth associated with Zn deficiency and growth from birth to discharge before and after implementing a DBM program.

Design/Methods: Retrospective cohort study of infants born at Parkland Hospital  < 33 wks gestational age (GA) or < 1500 g between June 2015 and June 2021. Growth was assessed by the change (Delta) in Z-scores of weight, length, fronto-occipital circumference (FOC) and BMI from birth to discharge (Delta BMIz). Serum Zn concentration was measured for infants (1) with excessive decrease in weight or length Z-scores from birth (Pavageau 2018), despite our adjustable feeding approach (Brion 2019) or (2) who had risk factors for Zn deficiency (e.g., short bowel syndrome). Zn deficiency was defined as serum Zn concentration < 0.74 mcg/mL (Finch 2015). Statistical analysis included ANOVA, chi-square analysis, logistic regression analysis and multiple linear regression analysis. 

Results: The cohort included a total of 1577 infants. Weight, length and FOC growth from birth to discharge did not change significantly after DBM implementation; however, Delta BMIz decreased significantly (Table 1). During the DBM program, Zn deficiency was more frequent in infants who received DBM (49/304, 16%) than those who did not (6/93, 7%) (P=0.02). Factors associated with deficiency included GA, sex and DBM feeding (Table 2). At the time of diagnosis of Zn deficiency [35.8 ± 3.1 wks (mean±SD) PMA], these infants had an average enteral intake of 144 ± 17 kcal/kg/day, protein 4.7 ± 0.5 g/kg/day and Zn 1.9 ± 0.3 mg/kg/day. The adjusted odds of mortality were lower with increasing GA and Apgar score at 5 minutes, and with any type of BM versus formula only (Table 3).Conclusion(s): DBM implementation did not significantly affect average change in weight, length or FOC accretion from birth to discharge but reduced Delta BMIz. This may be in part due to increasing caloric and protein intake and diagnosing and correcting Zn deficiency in infants who developed poor growth during DBM feeding. During the DBM program, BM feeding (DBM or MOM) was associated with lower mortality than with formula only.  
Table 1. Change in Z-scores from Birth to Discharge Before and After DBM Implementation in INfants < 33 weeks or < 1500g
Table 2. Factors Associated with Diagnosis of Zn Deficiency Among Infants < 33 weeks or < 1500g after DBM Program Implementation, January 2020- June 2021