Creamatocrit analysis of human milk overestimates fat and energy content when compared to a human milk analyzer using mid-infrared spectroscopy

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.

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.

Use of human milk and fortification in the NICU

Human milk is the gold standard to provide nutritional support for all healthy and sick newborn infants including the very low birth weight (VLBW) infant (<1500 g). It has both nutritional and anti-infective properties which are especially important for these infants at risk for sepsis and necrotizing enterocolitis. Human milk alone is insufficient to meet the nutritional needs for VLBW infants, especially protein and minerals. There is a conundrum between achieving the nutritional, immunologic, developmental, psychological, social, and economic benefit with human milk vs. the inadequate growth with unfortified human milk for VLBW leading to nutritional inadequacy, growth failure and poor neurodevelopmental outcome. The use of multicomponent fortifiers to increase calories and provide additional protein, vitamins, and minerals has been associated with short-term benefits in growth. Most current fortifiers are derived from cow's milk, however there are concerns regarding a possible association between the use of cow's milk-based fortifier and NEC. There is also an exclusive human milk diet with a fortifier derived solely from human milk. There are three approaches for fortifying human milk and include fixed dosage or "blind fortification", adjustable fortification using the blood urea nitrogen as a surrogate for protein nutriture to modify dosage of fortification, and targeted, individualized fortification that is based on periodic human milk analysis.

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.

Chylothorax in the neonate-A stepwise approach algorithm

BACKGROUND

Chylothorax in neonates results from leakage of lymph from thoracic lymphatic ducts and is mainly congenital or posttraumatic. The clinical course of the effusion is heterogeneous, and consensus on treatment, timing, and modalities of measures has not yet been established. This review aims to present, along with levels of evidence and recommendation grades, all current therapeutic possibilities for the treatment of chylothorax in neonates.

METHODS

An extensive search of publications between 1970 and 2020 was performed in the PubMed, Cochrane Database of Systematic Reviews, and UpToDate databases. A stepwise approach algorithm was proposed for both congenital and traumatic conditions to guide the clinician in a rational and systematic way for approaching the treatment of neonates with chylothorax.

DISCUSSION AND CONCLUSION

The treatment strategy for neonatal chylothorax generally involves supportive care and includes drainage and procedures to reduce chyle flow. A stepwise approach starting with the least invasive method is advocated. Progression in the invasiveness of treatment options is determined by the response to previous treatments. A practical stepwise approach algorithm is proposed for both, congenital and traumatic chylothoraces.

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

Introduction: Human milk (HM) is the ideal enteral feeding for nearly all infants and offers unique benefits to the very low birthweight (VLBW) infant population. It is a challenge to meet the high nutrient requirements of VLBW infants due to the known variability of HM composition. Human milk analysis (HMA) assesses the composition of HM and allows for individualized fortification. Due to recent U.S. Food and Drug Administration (FDA) approval, it has relatively recent availability for clinical use in the US.

Aim: To identify current practices of HMA and individualized fortification in neonatal intensive care units (NICUs) across the United States (US) and to inform future translational research efforts implementing this nutrition management method.

Methods: An institutional review board (IRB) approved survey was created and collected data on the following subjects such as NICU demographics, feeding practices, HM usage, HM fortification practices, and HMA practices. It was distributed from 10/30–12/21/2020 via online pediatric nutrition groups and listservs selected to reach the intended audience of NICU dietitians and other clinical staff. Each response was assessed prior to inclusion, and descriptive analysis was performed.

Results: About 225 survey responses were recorded during the survey period with 119 entries included in the analysis. This represented 36 states and Washington D.C., primarily from level III and IV NICUs. HMA was reported in 11.8% of responding NICUs. The most commonly owned technology for HMA is the Creamatocrit Plus TM (EKF Diagnostics), followed by the HM Analyzer by Miris (Uppsala, Sweden). In NICUs practicing HMA, 84.6% are doing so clinically.

Discussion: Feeding guidelines and fortification of HM remain standard of care, and interest in HMA was common in this survey. Despite the interest, very few NICUs are performing HMA and individualized fortification. Barriers identified include determining who should receive individualized fortification and how often, collecting a representative sample, and the cost and personnel required.

Conclusions: Human milk analysis and individualized fortification are emerging practices within NICUs in the US. Few are using it in the clinical setting with large variation in execution among respondents and many logistical concerns regarding implementation. Future research may be beneficial to evaluate how practices change as HMA and individualized fortification gain popularity and become more commonly used in the clinical setting.

Reproducibility of the creamatocrit technique for the measurement of fat content in human milk

Quantification of human milk (HM) fat is important for determining the energy intake of infants. The simplest and most rapid method is the creamatocrit method. However, the reliability of the creamatocrit has not been comprehensively investigated. The aims of this study were to test the inter- and-intra-rater reliability of: 1) HM sampling after hand- or-machine mixing methods and 2) HM fat measurement by the creamatocrit method. Inter-and-intra rater HM sampling after hand- or-machine mixing methods had high intraclass correlation coefficient (>0.91). Inter-rater reliability of measurement of HM with low fat (<2%) resulted in high variability (median coefficient of variations (CVs) > 15%). Intra- and inter-rater reliability of measurement of HM with higher fat (>3.5%) had low variability (median CVs < 10%). As the greatest variation in the creamatocrit method occurred during the measurement of HM samples with low fat, duplicate readings are necessary to reduce discrepancies in every HM fat determination.

Infrared analyzers for the measurement of breastmilk macronutrient content in the clinical setting

INTRODUCTION

There is growing interest in the possibility of measuring the macronutrient content of human milk. Several studies that intend to validate commercially available human milk analyzers have been published with inconsistent results. This review will focus on currently available, verified methodologies for analyzing macronutrients in human milk.

AREAS COVERED

A literature search was conducted in the PubMed database. Five milk analyzers were chosen to be included in this review: MIRIS (Uppsala, Sweden) (seven articles found), Calais (Cleveland, United States) (four articles), SpectraStar (Brookfield, United States) (four articles), MilkoScan (Hillerdo, Denmark) (two articles), and Delta LactoScope (Stockholm, Sweden) (one article). The following information was extracted from published manuscripts: measuring device, sample preparation, purpose of the study, type of macronutrients studied, results, and conclusions.

EXPERT OPINION

Infrared spectroscopy can be an accurate and reliable technology for assessing the macronutrient content of human milk, specifically crude protein, and total fat. However, an optimal handling of samples, the development of standardized quality-control protocols, and an improvement in calibration procedures are required before the full implementation of infrared technology in neonatal units.

Optimizing individual nutrition in preterm very low birth weight infants: double-blinded randomized controlled trial

OBJECTIVE

In preterm neonates fed human milk, fortification may be adjusted by (1) optimization, based on growth rate and serum nutrient analyses, or (2) individualization, based on serial milk nutrient analyses. The primary aim was to determine whether individualized plus optimized nutrition (experimental) improves velocity of weight gain and linear growth from birth to endpoint (36 weeks postmenstrual age or discharge) when compared with optimized nutrition alone (controls).

STUDY DESIGN

Double-blinded parallel group randomized trial in 120 neonates <29 weeks gestational age (GA) or <35 weeks and small for GA (birth weight < 10th centile).

RESULT

Weight-gain velocity (13.1 ± 2.1, n = 57 controls, vs. 13.0 ± 2.6 g kg^-1 day^-1, n = 59 experimental, P = 0.87), linear growth (0.9 ± 0.2, n = 55, vs. 0.9 ± 0.2 cm week^-1, n = 52, P = 0.90) and frequency of weight/length disproportion (2% vs. 2%, P = 0.98) were similar in both groups.

CONCLUSIONS

Individualized plus optimized nutrition does not improve weight gain, linear growth, or weight/length disproportion at endpoint versus optimized nutrition alone.

The Practicality of Feeding Defatted Human Milk in the Treatment of Congenital Chylothorax

Introduction: Congenital chylothorax (CC) is a rare and life-threating condition. Since its treatment is founded on the elimination of long-chain fatty acids from the diet, breastfeeding has been traditionally contraindicated. However, breast milk could be very beneficial due to its immunological and nutritional benefits. Only limited research has been published about the usage of modified-fat breast milk (MBM) in chylothorax treatment. Methods and Results: Systematic review methods were used by two independent reviewers. Only a few case report studies (quality assessment on the domains of the GRADE approach), two small controlled studies, a retrospective study, and some test-tube-based laboratory research met the inclusion criteria. Despite this, we have observed a widespread clinical adoption of this novel treatment in health institutions. Data suggest that modified-fat breast milk does facilitate the resolution of chylothoraces. Refrigerated centrifuge (2°C, 3,000 rpm for 15 minutes) and syringe fat removal methods were the most efficient options in terms of fat reduction. Conclusions: Feeding of human milk is advisable in CC and feasible by means of a simple milk defatting procedure. Open questions remain, related to length and degree of fat restriction and need for individualized fortification of defatted breast milk.

Macronutrient Analysis of Modified-Fat Breast Milk Produced by 3 Methods of Fat Removal

BACKGROUND

Infants with chylothorax after congenital heart disease surgery are commonly treated using modified-fat breast milk. The effect of fat removal on breast milk macronutrients remains unclear. We compared macronutrient content of breast milk with breast milk skimmed using 3 methods, including a novel device, a cream separator.

METHODS

Thawed frozen breast milk samples from 30 women were defatted using refrigerated centrifuge, cream separator, and manual separation after refrigeration. We used standard assays to measure energy, protein, and fat content of breast milk samples.

RESULTS

All fat removal methods yielded skimmed breast milk with substantially lower fat and energy content. Mean energy content in breast milk skimmed by centrifuge (36.7 [SD 3.6] kcal/100 mL) was similar to that from cream separator (38.8 [3.5] kcal/100 mL). Both centrifuge and cream separator methods removed almost all fat and substantially more fat than the manual fat removal method. For unprocessed milk, energy and fat content estimated by creamatocrit was similar to reference method measurements; in skimmed milk, the creamatocrit significantly overestimated fat content. Mean protein content of skimmed breast milk was similar to unprocessed breast milk (mean 1.25 [0.31] g/100 mL).

CONCLUSION

Breast milk fat removal did not significantly alter protein levels. In skimmed breast milk, the overestimation of fat content using creamatocrit method suggests a need for more accurate bedside methods to assess macronutrient content. The similar macronutrient composition of breast milk skimmed by cream separator and centrifuge suggests the potential for cream separator use as a new, portable defatting method for hospitals and families.

The effect of maternal habitus on macronutrient content of human milk colostrum

OBJECTIVE

There is a paucity of studies on the impact of maternal body mass index (BMI) on macronutrient content of human milk colostrum (HMC). The objective of this study was to compare macronutrient content of HMC in healthy women of term infants in relation to their BMI. We hypothesized that mother habitus influences human milk colostrum content.

METHOD

Colostrum was collected from 109 healthy mothers of hospitalized healthy term infants divided into four prepregnancy BMI groups: 12 underweight, 59 normal weight, 20 overweight, and 18 obese women between 24 and 72 h after birth. Macronutrient content was measured using mid-infrared spectroscopy.

RESULTS

There were no significant differences in macronutrients between the BMI groups. We performed four separate stepwise backward multiple regression analyses taking into account fat, carbohydrate, protein or energy content as dependent variables and maternal BMI, parity, gestational age, infant gender, maternal age, maternal education, mode of delivery and time postdelivery. In these analyses, fat, carbohydrate and energy content were not related to maternal BMI, while protein content was significantly and positively correlated with BMI (P=0.008) and negatively correlated with gestational age (P=0.004) and time postdelivery (P<0.001). Colostrum carbohydrate content was positively correlated with parity. Colostrum fat and energy content were negatively correlated with maternal age and positively correlated with parity.

CONCLUSION

Most macronutrient and energy content of colostrum are unaffected by prepregnancy maternal BMI, with the exception of protein content that is positively related to maternal BMI.

Validation of mid-infrared spectroscopy for macronutrient analysis of human milk

OBJECTIVE

Human milk has considerable variation in its composition. Hence, the nutrient profile is only an estimate and can result in under- or over-estimation of the intake of preterm infants. Mid-infrared (MIR) spectroscopy is an evolving technique for analyzing human milk but needs validation before use in clinical practice.

STUDY DESIGN

Human milk samples from 35 mothers delivering at 35 weeks to term gestation were analyzed for macronutrients by MIR spectroscopy and by standard laboratory methods using Kjeldahl assay for protein, Mojonnier assay for fat and high-pressure liquid chromatography assay for lactose.

RESULTS

MIR analysis of the macronutrients in human milk correlated well with standard laboratory tests with intraclass correlation coefficients of 0.997 for fat, 0.839 for protein and 0.776 for lactose. Agreement between the two methods was excellent for fat, and moderate for protein and lactose (P<0.001).

CONCLUSIONS

This methodological paper provides evidence that MIR spectroscopy can be used to analyze macronutrient composition of human milk. Agreement between the methodologies varies by macronutrient.

"Bed Side" Human Milk Analysis in the Neonatal Intensive Care Unit: A Systematic Review

Human milk analyzers can measure macronutrient content in native breast milk to tailor adequate supplementation with fortifiers. This article reviews all studies using milk analyzers, including (i) evaluation of devices, (ii) the impact of different conditions on the macronutrient analysis of human milk, and (iii) clinical trials to improve growth. Results lack consistency, potentially due to systematic errors in the validation of the device, or pre-analytical sample preparation errors like homogenization. It is crucial to introduce good laboratory and clinical practice when using these devices; otherwise a non-validated clinical usage can severely affect growth outcomes of infants.

Fortification of human milk for preterm infants

Human milk is the preferred feeding for all infants, including those of very low birth weight (<1500 g). It has both nutritional and anti-infective properties which are especially important for infants at risk for sepsis and necrotizing enterocolitis. When maternal milk is not available or the amount produced is not sufficient to meet daily needs, donor human milk may (should) be used in its place. However, donor human milk is generally term in quality and likely has insufficient protein to promote appropriate growth. Whether donor or mother's own milk, fortification of human milk is required to meet nutrient requirements for growth and development for these preterm infants who are at high risk for growth faltering during the hospital stay. There are multiple strategies and products that may be employed to support desired growth rates. The advent of human milk analyzers may be helpful in a more customized approach to fortification.

Comparison of gravimetric, creamatocrit and esterified fatty acid methods for determination of total fat content in human milk

The gravimetric method is considered the gold standard for measuring the fat content of human milk. However, it is labor intensive and requires large volumes of human milk. Other methods, such as creamatocrit and esterified fatty acid assay (EFA), have also been used widely in fat analysis. However, these methods have not been compared concurrently with the gravimetric method. Comparison of the three methods was conducted with human milk of varying fat content. Correlations between these methods were high (r(2)=0.99). Statistical differences (P<0.001) were observed in the overall fat measurements and within each group (low, medium and high fat milk) using the three methods. Overall, stronger correlation with lower mean (4.73g/L) and percentage differences (5.16%) was observed with the creamatocrit than the EFA method when compared to the gravimetric method. Furthermore, the ease of operation and real-time analysis make the creamatocrit method preferable.

Human Milk Analysis Using Mid-Infrared Spectroscopy

BACKGROUND

The composition of human milk is known to vary with length of gestation, stage of lactation, and other factors. Human milk contains all nutrients required for infant health but requires fortification to meet the needs of low-birth-weight infants. Without a known nutrient profile of the mother's milk or donor milk fed to a baby, the composition of the fortified product is only an estimate. Human milk analysis has the potential to improve the nutrition care of high-risk newborns by increasing the information about human milk composition. Equipment to analyze human milk is available, and the technology is rapidly evolving. This pilot study compares mid-infrared (MIR) spectroscopy to reference laboratory milk analysis.

METHODS

After obtaining informed consent, we collected human milk samples from mothers of infants weighing <2 kg at birth. Duplicate samples were analyzed for macronutrients by MIR and by reference laboratory analysis including Kjeldahl for protein, Mojonnier for fat, and high-pressure liquid chromatography for lactose. Intraclass correlation coefficients, Bland-Altman scatter plots, and paired t tests were used to compare the two methods.

RESULTS

No significant differences were detected between the macronutrient content of human milk obtained by MIR vs reference laboratory analysis.

CONCLUSIONS

MIR analysis appears to provide an accurate assessment of macronutrient content in expressed human milk from mothers of preterm infants. The small sample size of this study limits confidence in the results. Measurement of lactose is confounded by the presence of oligosaccharides. Human milk analysis is a potentially useful tool for establishing an individualized fortification plan.

Breast milk fat content of mothers to small-for-gestational-age infants

OBJECTIVE

Little is known about the composition of human milk (HM) expressed by mothers of asymmetrically growth-restricted infants. To test the null hypothesis that lactating mothers of small-for-gestational-age (SGA) infants produce milk with fat content similar to that of lactating mothers of infants whose growth is appropriate for gestational age (AGA).

STUDY DESIGN

Fifty-six lactating mothers of newborns (26 SGA and 30 AGA) were recruited within the first 3 days of delivery. Creamatocrit (CMT) levels in HM were measured at 72 h, 7 days and 14 days postdelivery in capillary tubes after centrifugation at 9000 r.p.m. for 5 min.

RESULT

The groups did not differ in terms of maternal age, body mass index, gestational age (GA), pregnancy weight gain and parity. They differed significantly in terms of infant's birth weight by design. The mean CMT levels at the three time points were similar for the two groups. This remained true when timing of the sample (colostrum, transitional, mature milk) was introduced as a confounder in the analysis of variance (general linear model).

CONCLUSION

Fat content of HM is not affected by fetal growth status. We suggest that mothers of SGA infants may be reassured that their milk contains adequate amount of fat that is appropriate for the growth of their infants.

Challenges in breast milk fortification for preterm infants

PURPOSE OF REVIEW

To outline new evidence published from 2013 to 2014 about breast milk fortification in preterm infants.

RECENT FINDINGS

Breast milk is the feeding choice for preterm infants because of its immunoprotective properties. However, breast milk's nutrient content is not sufficient for preterm infants, and interindividual variation is high. The variation challenges standard fortification, which assumes a standard breast milk composition. Two new fortification strategies (adjustable fortification and target fortification) optimize macronutrient intake and improve growth. Adjustable fortification uses blood urea nitrogen levels to adjust fortifier strength. Target fortification analyzes breast milk and fortifies macronutrients individually to achieve targeted intake. Its feasibility is shown in clinical routine. Current breast milk analyzers used for target fortification achieve acceptable precision for protein and fat but not for lactose and energy. Evidence of benefits for postdischarge breast milk fortification is lacking. Eliminating cow's milk products and feeding exclusively breast milk may decrease the occurrence of feeding intolerance and necrotizing enterocolitis. To facilitate exclusively breast milk diets, a collaboration of prenatal, nutrition and lactation stakeholders is key. Fortification increases osmolality; however, safety cutoffs to prevent necrotizing enterocolitis are unclear. There is also new evidence that composition and structure of various macronutrients and micronutrients affect growth and development, and might play a role in future fortification concepts.

SUMMARY

Recent research focuses on the variability of breast milk composition, its impact on postnatal growth patterns and the usefulness of target fortification. As well, diets exclusively composed of human milk are a promising approach to improve feeding tolerance. For safe fortification, osmolality cutoff levels are needed.

Target fortification of breast milk: levels of fat, protein or lactose are not related

AIM

Target fortification (TFO) of breast milk has the potential to improve the nutritional outcomes of preterm infants. However, the primary logistic constraint in introducing TFO is analysers that rapidly and accurately analyse macronutrients (fat, protein and lactose). In this prospective observational study, we aim to evaluate whether the levels of fat, protein and carbohydrate could be predicted from one key macronutrient.

METHODS

Macronutrient components were measured in 543 breast milk samples using validated chemical micro-methods. Correlation analysis for fat versus protein, fat versus lactose and lactose versus protein was computed using Pearson's correlation.

RESULTS

The concentration of the macronutrients ranged from 0.7 to 10.3 g/100 mL (3.7 ± 1.2, mean ± SD) for fat, 0.7 to 3.2 g/100 mL (1.3 ± 0.3) for protein and 4.0 to 8.8 g/100 mL (5.8 ± 0.7) for lactose, respectively. There was no correlation between the three macronutrients.

CONCLUSION

This lack of correlation underlines the importance of routine and accurate analysis of all three macronutrients in breast milk prior to TFO.

A systematic review and meta-analysis of the nutrient content of preterm and term breast milk

Background

Breast milk nutrient content varies with prematurity and postnatal age. Our aims were to conduct a meta-analysis of preterm and term breast milk nutrient content (energy, protein, lactose, oligosaccharides, fat, calcium, and phosphorus); and to assess the influence of gestational and postnatal age. Additionally we assessed for differences by laboratory methods for: energy (measured vs. calculated estimates) and protein (true protein measurement vs. the total nitrogen estimates).

Methods

Systematic review results were summarized graphically to illustrate the changes in composition over time for term and preterm milk. Since breast milk fat content varies within feeds and diurnally, to obtain accurate estimates we limited the meta-analyses for fat and energy to 24-hour breast milk collections.

Results

Forty-one studies met the inclusion criteria: 26 (843 mothers) preterm studies and 30 (2299 mothers) term studies of breast milk composition. Preterm milk was higher in true protein than term milk, with differences up to 35% (0.7 g/dL) in colostrum, however, after postnatal day 3, most of the differences in true protein between preterm and term milk were within 0.2 g/dL, and the week 10–12 estimates suggested that term milk may be the same as preterm milk by that age. Colostrum was higher than mature milk for protein, and lower than mature milk for energy, fat and lactose for both preterm and term milk. Breast milk composition was relatively stable between 2 and 12 weeks. With milk maturation, there was a narrowing of the protein variance. Energy estimates differed whether measured or calculated, from −9 to 13%; true protein measurement vs. the total nitrogen estimates differed by 1 to 37%.

Conclusions

Although breast milk is highly variable between individuals, postnatal age and gestational stage (preterm versus term) were found to be important predictors of breast milk content. Energy content of breast milk calculated from the macronutrients provides poor estimates of measured energy, and protein estimated from the nitrogen over-estimates the protein milk content. When breast milk energy, macronutrient and mineral content cannot be directly measured the average values from these meta-analyses may provide useful estimates of mother’s milk energy and nutrient content.

Fortification of human milk in very low birth weight infants (VLBW <1500 g birth weight)

The American Academy of Pediatrics supports the feeding of human milk for all infants. Very-low-birth-weight and extremely low-birth-weight infants especially can benefit from the immune and neurodevelopmental effects of human milk. However, human milk alone is nutritionally inadequate for the rapid growth of the very-low-birth-weight infant during a critical window for brain development and requires fortification to meet current recommendations. There are a variety of products, devices, and strategies that can be used to fine tune nutritional support of these very vulnerable infants.