Human Milk Macronutrient Loss Differs Between Enteral Tube Feeding Systems

Background: Due to immature feeding reflexes, many premature infants in the NICU require prolonged periods of enteral tube feeding. Prior research has demonstrated significant macronutrient losses from breastmilk with enteral feeding systems, especially fat. Fat intake is critical to rapid brain and lung growth during NICU hospitalization, with growth linked to neurodevelopmental outcomes. As breastmilk reduces overall morbidity and mortality, optimizing nutrient delivery is crucial. Enteral tube feeds are typically delivered via syringe pump or feeding bag systems; however, it is unknown whether nutrient loss differs between these systems.

Objectives: To compare breastmilk macronutrient losses after delivery through syringe and feeding bag enteral feeding systems.

Design/Methods: Frozen de-identified human milk was combined into 10 pools. Moog feeding bags and NeoMed 35 ml syringes were connected to extension tubing and a 5 French feeding tube for simulations. For each simulation, 20 ml of milk was delivered over 30, 60, 90, or 180 minutes (continuous feeds). This was repeated for each pool of milk (Figure 1). Baseline and post-delivery macronutrient composition was analyzed using a mid-infrared milk analyzer. Statistical analyses were performed using repeated measures ANOVA or Mann-Whitney tests.

Results: A significant reduction in fat content with prolonged of feeding time (p < 0.0001) and use of a feeding bag was observed (p=0.0013). With direct comparison of syringe pump to feeding bag, a significant difference in fat loss was demonstrated at 180 minutes (p=0.003). Syringe pumps demonstrated an average fat loss of 9% at 30 minutes, 15% at 60 minutes, 17% at 90 minutes, and 22% at 180 minutes. With feeding bags, average fat loss was 16% at 30 minutes, 22% at 60 minutes, 30% at 90 minutes, and 43% at 180 min (Figure 2). Syringe pumps demonstrated a 9% loss and feeding bag systems demonstrated an average of 20% loss in energy content (kcal) at 180 minutes (p-=0.003).

Conclusions: Prolongation of enteral feeding times results in significant losses in fat and energy content of breast milk. Losses are greater with feeding bag systems than syringe pump systems. Further investigation is needed to quantify the impact of pasteurization and to identify methods to optimize nutrient delivery.