Exploring Innovations in Human Milk Analysis in the Neonatal Intensive Care Unit: A Survey of the United States

Use of technology in neonatal nutrition

There have been rapidly expanding uses of technology to enhance and improve nutrition in our smallest patients. Optimized nutrition in the neonatal patient is linked to improved outcomes, specifically neurodevelopmental outcomes and decreased length of stay. Despite advances in neonatal care that have improved survival, many patients being discharged from the neonatal intensive care unit are doing so with poor postnatal growth. Because the neonatal brain doubles in size from 20 weeks gestation to term, it is essential to focus care efforts on nutrition to optimize brain growth and development. This review focuses on three exciting areas of neonatal research, including the analysis of macronutrients in breast milk, measurement of body composition, and use of telemedicine.

Human Milk-The Biofluid That Nourishes Infants from the First Day of Life

Human milk is a biofluid with a unique composition among mammalian milks. Besides this milk's major components, its bioactive compounds, like hormones, immune factors, and oligosaccharides, are unique and important for infant growth and development. The best form of nutrition for term and preterm infants is the mother's own milk. However, in the absence of the mother's own milk, donor milk should be made available. Milk banks support neonatal intensive care units by providing preterm infants with human milk that generally has reasonable nutritive value for this sensitive population. However, neither mother's own milk nor donor milk has sufficient energy content for the growth of preterm babies, so adequate human milk supplementation is crucial for their progress. Due to the different characteristics of human breast milk, as well as ubiquitous environmental pollutants, such as microplastics, new methods are required for monitoring the quality and characteristics of human milk, which will lay a solid foundation for the further development and progress of human milk research.

Nutritional composition of human milk and its association with maternal and perinatal factors

OBJECTIVE

The objective of this study was to evaluate the influence of maternal and perinatal factors on the nutritional composition of human milk.

METHODS

A cross-sectional study was conducted between November 2018 and January 2020, with 181 donors selected in Tertiary Health Units of the Unified Health System - from one collection station and five Human Milk Banks. Data were collected through a standardized questionnaire. To be fit to be a donor in a Human Milk Banks and produce mature milk were the eligibility criteria to participate in the study. We excluded milk samples with Dornic acidity above 8° D. The dependent variables were the macronutrients of human milk (i.e., carbohydrates, proteins, lipids, and total energy), that were analyzed using spectroscopy with the Miris Human Milk Analyzer™. The maternal and perinatal factors were the independent variables.

RESULTS

Women with pre-gestational obesity and gestational weight gain above the recommendation showed a lower protein concentration compared to eutrophic women (median=0.8, interquartile range (IQR): 0.7-0.9 vs. median=0.8, and IQR: 0.8-1.0) and those with adequate gestational weight gain (median=0.8, IQR: 0.7-0.9 vs. median=0.9, and IQR: 0.8-1.0), respectively. The other analyzed factors (i.e., maternal habits, comorbidities, and perinatal factors) were not associated with the nutritional composition of human milk.

CONCLUSIONS

The assessment of factors associated with the nutritional composition of human milk is extremely important to assist postpartum care. Pre-gestational obesity and inadequate gestational weight gain were the only factors statistically associated with the nutritional composition of human milk as they impacted its protein content.

Human Milk Fortification Strategies in the Neonatal Intensive Care Unit

Multicomponent fortification is the standard of care to support short-term growth in preterm infants receiving human milk. There is no consensus regarding the optimal timing, method, or products used to fortify human milk. Both bovine milk-based and human milk-based human milk fortifiers are safe options, though increased fortification and enrichment may be needed to achieve adequate growth. Additional studies are needed to evaluate newer fortifier products and fortification strategies.

Human Milk Calorie Guide: A Novel Color-Based Tool to Estimate the Calorie Content of Human Milk for Preterm Infants

Fixed-dose fortification of human milk (HM) is insufficient to meet the nutrient requirements of preterm infants. Commercial human milk analyzers (HMA) to individually fortify HM are unavailable in most centers. We describe the development and validation of a bedside color-based tool called the 'human milk calorie guide'(HMCG) for differentiating low-calorie HM using commercial HMA as the gold standard. Mothers of preterm babies (birth weight ≤ 1500 g or gestation ≤ 34 weeks) were enrolled. The final color tool had nine color shades arranged as three rows of three shades each (rows A, B, and C). We hypothesized that calorie values for HM samples would increase with increasing 'yellowness' predictably from row A to C. One hundred thirty-one mother's own milk (MOM) and 136 donor human milk (DHM) samples (total n = 267) were color matched and analyzed for macronutrients. The HMCG tool performed best in DHM samples for predicting lower calories (<55 kcal/dL) (AUC 0.87 for category A DHM) with modest accuracy for >70 kcal/dL (AUC 0.77 for category C DHM). For MOM, its diagnostic performance was poor. The tool showed good inter-rater reliability (Krippendorff's alpha = 0.80). The HMCG was reliable in predicting lower calorie ranges for DHM and has the potential for improving donor HM fortification practices.

Dilemmas in human milk fortification

Fortification of human milk is the standard of care for very low birth weight (VLBW) infants and is required to support adequate postnatal growth and development. Achieving adequate growth velocity and preventing growth faltering is critical for the developing neonatal brain and optimizing long-term neurodevelopmental outcomes. Mother's milk is the gold standard nutrition to feed preterm infants, however, it does not provide the nutrients needed to support the growth of VLBW infants. After the decision is made to use mother's milk (if available) or alternatively, donor human milk, many dilemmas exist with regards to additional treatment decisions surrounding the type of fortification to use, when to fortify, and the duration of fortification. In this article, we will review the differences in mother's milk compared to donor milk, the different types of human milk fortifiers, the optimal timing of fortification, and discuss when to discontinue human milk fortification.

Associations of Macronutrient Intake Determined by Point-of-Care Human Milk Analysis with Brain Development among very Preterm Infants

Point-of-care human milk analysis is now feasible in the neonatal intensive care unit (NICU) and allows accurate measurement of macronutrient delivery. Higher macronutrient intakes over this period may promote brain growth and development. In a prospective, observational study of 55 infants born at <32 weeks’ gestation, we used a mid-infrared spectroscopy-based human milk analyzer to measure the macronutrient content in repeated samples of human milk over the NICU hospitalization. We calculated daily nutrient intakes from unfortified milk and assigned infants to quintiles based on median intakes over the hospitalization. Infants underwent brain magnetic resonance imaging at term equivalent age to quantify total and regional brain volumes and fractional anisotropy of white matter tracts. Infants in the highest quintile of energy intake from milk, as compared with the lower four quintiles, had larger total brain volume (31 cc, 95% confidence interval [CI]: 5, 56), cortical gray matter (15 cc, 95%CI: 1, 30), and white matter volume (23 cc, 95%CI: 12, 33). Higher protein intake was associated with larger total brain (36 cc, 95%CI: 7, 65), cortical gray matter (22 cc, 95%CI: 6, 38) and deep gray matter (1 cc, 95%CI: 0.1, 3) volumes. These findings suggest innovative strategies to close nutrient delivery gaps in the NICU may promote brain growth for preterm infants.

Using Nature to Nurture: Breast Milk Analysis and Fortification to Improve Growth and Neurodevelopmental Outcomes in Preterm Infants

Premature infants are born prior to a critical window of rapid placental nutrient transfer and fetal growth-particularly brain development-that occurs during the third trimester of pregnancy. Subsequently, a large proportion of preterm neonates experience extrauterine growth failure and associated neurodevelopmental impairments. Human milk (maternal or donor breast milk) is the recommended source of enteral nutrition for preterm infants, but requires additional fortification of macronutrient, micronutrient, and energy content to meet the nutritional demands of the preterm infant in attempts at replicating in utero nutrient accretion and growth rates. Traditional standardized fortification practices that add a fixed amount of multicomponent fortifier based on assumed breast milk composition do not take into account the considerable variations in breast milk content or individual neonatal metabolism. Emerging methods of individualized fortification-including targeted and adjusted fortification-show promise in improving postnatal growth and neurodevelopmental outcomes in preterm infants.