Impact of Holder Pasteurization and Preanalytical Handling Techniques on Fat Concentration in Donor Human Milk: A Scoping Review.

BACKGROUND: Donor human milk (DHM) is an essential source of nutrition among high-risk infants (e.g., premature and low-birth weight). Holder pasteurization, a common step in DHM processing, is known to partially alter the composition of DHM; however, the impact on fat composition is historically inconsistent. OBJECTIVES: This scoping review aimed to broadly review the literature on the impact of Holder pasteurization on the fat content in DHM, with a focus on preanalytical sample mixing. METHODS: A systematic search of original, peer-reviewed research articles was conducted on 11 July, 2022. Articles were included if they compared matched raw (control) and Holder-pasteurized human milk samples and measured total lipids, cholesterol, and individual classes of fatty acids. Article review and selection was conducted by 2 independent reviewers. RESULTS: The search yielded 26 original, peer-reviewed research articles published between 1978 and 2022. Overall methodology varied considerably between studies. When study methods described any mixing for collecting raw milk, 1 (17%) of the 6 of studies reported a small change in total fat concentration following pasteurization (<5%). Alternatively, among studies that did not describe methods for mixing raw milk to ensure a representative sample, 10 (56%) of the 18 reported a significant change (≥± 5%) in total fat concentration, with changes ranging from -28.6% to +19.4%. CONCLUSIONS: This review suggests that inconsistent findings regarding the impact of Holder pasteurization on fat may be related to study methodologies, particularly preanalytical sample mixing. More research considering the role of preanalytical handling procedures and methodologies is necessary to help clarify the impact of Holder pasteurization on human milk composition.

Deciphering macronutrient information about human milk.

Clinicians caring for small, vulnerable newborns increasingly have access to specific nutritional information about human milk through point-of-care analyzers and labeled products. It is critical for clinicians to recognize that there is considerable variability in how human milk nutritional data are derived and reported, which impacts the interpretation of nutritional values, comparison of nutritional data between products, and ultimately the ability to deliver optimal nutritional care. This article distills key issues that will enable clinicians to interpret human milk nutritional labels/analysis more effectively, ultimately allowing them to make better decisions about dietary strategies. We aim to empower clinicians to ask questions about milk sampling techniques, reported nutrient values, analysis techniques, and milk bank pooling practices. This knowledge can put human milk nutrient values in context, improve clinical care, and help to drive more rigorous research for exploring the impact of human milk feeding on infant outcomes.

Point-of-care human milk concentration by passive osmosis: comprehensive analysis of fresh human milk samples.

OBJECTIVE: Preterm infants need enrichment of human milk (HM) for optimal growth. This study evaluated a novel, point-of-care human milk concentration (HMC) process for water removal from fresh HM samples by passive osmotic concentration. STUDY DESIGN: Nineteen fresh HM samples were concentrated by incubation with the HMC devices for 3 h at 4 °C. Pre- and post-concentration HM samples were compared by HM properties for: pH, osmolality, macronutrients, enzyme activity, bioactive, and total cell viability. RESULTS: Passive osmotic concentration reduced HM volume by an average of 16.3% ± 3.8% without a significant effect on pH or cell viability. Ten of the 41 HM components did not differ significantly (p > 0.05) between pre- and post-concentration samples. Twenty-three increased within the expected range by volume reduction. Six increased more than expected, two less than expected, and none decreased significantly. CONCLUSION: Passive osmotic concentration of fresh HM can concentrate HM components by selective removal of water. HM osmolality and pH remained within neonatal feeding parameters.

Donation barriers, enablers, patterns and predictors of milk bank donors in the United States and United Kingdom.

Pasteurised donor human milk is recommended for very low birthweight infants who do not have access to their mother's milk. Although the use of donor milk continues to increase, little is known about the donation experiences of milk bank donors. We aimed to describe and compare enablers, barriers and patterns of human milk donation and identify factors predicting donation volume in a convenience sample of approved milk bank donors in the United Kingdom and the United States. A cross-sectional online survey was conducted from August 2022 to December 2022. Approved milk bank donors (n = 556) from three milk banks in the United States (n = 369, Mothers' Milk Bank of Florida, Mother's Milk Bank of North Texas and Northwest Mothers Milk Bank) and one milk bank in the United Kingdom (n = 187, Hearts Milk Bank) completed the survey. A substantial portion of donors in both settings reported participating in other forms of milk exchange (51% of U.S. donors vs. 39% of UK donors, p = 0.009). Top donation barriers reported in both settings were completing the serological screening and having enough space to store collected milk. Most donors started donating when their infant was 3 months old or older and reported donating mature milk. The most common source of information related to milk banking in each setting was the internet (United Kingdom-70% vs. United States - 63%, p = 0.112). Variables that predicted lifetime donation volume differed between the United States and the United Kingdom, highlighting the importance of setting-specific milk banking research.

Human Milk Nutrient Composition Data is Critically Lacking in the United States and Canada: Results from a Systematic Scoping Review of 2017-2022.

Characterization of the nutrients in human milk is important to understand the dietary and developmental requirements of infants. The objective of this review was to summarize the state-of-the-science on the nutrient composition of human milk in the United States and Canada published from 2017 to 2022. Four databases were searched for randomized controlled studies and others given the scoping nature of this review. We limited type to mature milk collected 21 d postpartum and beyond from lactating individuals in the United States and Canada who gave birth at 37-wk gestation or later (full-term). Outcomes of interest included traditional macro- and micronutrients, including human milk oligosaccharides (HMOs), and milk volume. The publication date range was selected as January 1, 2017, to the day the literature search was performed. A total of 32 articles were included in the scoping review from primarily longitudinal cohort or cross-sectional designs. The most prevalent sample collection method was full-breast expression (n = 20) with most studies (n = 26) collecting samples from a single timepoint. Carbohydrates (HMOs [n = 12], glucose [n = 8], and lactose [n = 6]) and protein (n = 5) were the most frequently assessed nutrients in this body of work, with consensus among studies that glucose is present in limited concentrations compared to lactose (24-64 mg/dL compared with 6-7 g/dL) and that HMOs are influenced by temporality and secretor status. Included studies displayed an overall level of heterogeneity and sparsity paralleling previous reports and nutrient data in the USDA FoodData Central system. Much of the data extracted from retained articles generally provided analysis of a specific nutrient or group of nutrients. Moreover, many studies did not use the preferred analytical methods as outlined by the Human Milk Composition Initiative to increase measurement confidence. Up-to-date nutrient composition data of human milk is still greatly needed as it is paramount for the management of infant feeding, assessment of infant and maternal nutritional and health needs, and as a reference for infant formula development.

The Influence of Oligosaccharides when Measuring Lactose and Total Carbohydrates in Human Milk and Comparison of Methods.

BACKGROUND: Understanding how human milk impacts growth requires valid analytical methods for quantifying the composition. Lactose, the most abundant constituent in human milk and a predominant source of energy, is often assessed using methods borrowed from the bovine dairy industry. However, the carbohydrate matrices of bovine and human milk are quite different, especially as they relate to human milk oligosaccharides (HMOs), each with a terminal lactose unit that may influence analytical methods. OBJECTIVES: Our goals were to determine the extent to which HMOs influence common analytical methods for measuring carbohydrates in human milk and to compare common methods for measuring lactose. METHODS: Two sets of experiments were performed. In the first set, native and HMO-spiked human milk samples (n = 16 each) were assessed and compared using 4 methods: AOAC 2006.06 (based on the Megazyme enzymatic assay), BioVision enzymatic assay, ultraperformance LC with MS, and infrared analysis. In the second set, human milk samples (n = 20) were assessed using 2 methods approved for measuring lactose in bovine milk: AOAC 984.22 that uses high-performance LC and refractive index detection and AOAC 2006.06 prepared using both volume and weighted dilutions. RESULTS: Native and HMO-spiked samples were not significantly different in lactose using AOAC 2006.06 and ultraperformance LC with MS but were significantly different using BioVision (mean difference = 0.2 g/dL; 95% CI: 0.1, 0.4; P = 0.005). Total carbohydrate measurements assessed using infrared were also higher after HMO spiking (mean difference = 0.4 g/dL; 95% CI: 0.3, 0.6; P < 0.001). Only AOAC methods 984.22 and 2006.06 for measuring lactose were very highly correlated (r > 0.90, P < 0.001). CONCLUSIONS: AOAC methods 984.22 and 2006.06 are comparable for measuring lactose in human milk and are not influenced by HMOs. HMOs influence other enzymatic methods as well as infrared analysis, which leads to an overestimate of energy values. J Nutr 2023;x:xx.

Investigating donor human milk composition globally to develop effective strategies for the nutritional care of preterm infants: Study protocol.

BACKGROUND: Globally, almost 15 million infants are born prematurely each year, disproportionately affecting low and middle-income countries. In the absence of mother's milk, the World Health Organization recommends using donor human milk (DHM) due to its protective effect against necrotizing enterocolitis, a life-threatening intestinal disorder. The use of DHM is increasing globally, with many low and middle-income countries integrating donor milk banks into their public health strategies to reduce neonatal mortality, yet very little is known about the nutritional composition of DHM. Additional knowledge gaps include how DHM composition is influenced by milk banking practices, and whether preterm nutrient recommendations are achieved when DHM is used with commercially available fortifiers. METHODS: We designed a multi-site study with eight geographically diverse milk bank partners in high, middle, and low-income settings that will examine and compare a broad range of nutrients and bioactive factors in human milk from 600 approved milk bank donors around the world to create comprehensive, geographically diverse nutrient profiles for DHM. We will then simulate the random pooling of 2 to 10 donors to evaluate the impact of pooling as a potential strategy for milk banks to manage nutrient variability in DHM. Finally, we will evaluate whether commercially available fortifiers meet nutrient recommendations when used with DHM. DISCUSSION: We expect that results from this study will improve nutritional care globally for the growing number of preterm infants who receive donor human milk.

COVID-19 Severity Is Associated with Selenium Intake among Young Adults with Low Selenium and Zinc Intake in North Carolina.

Background: The effects of coronavirus disease 2019 (COVID-19) remain a global public health emergency because of the ensuing economic burden and death. With robust research into vaccines, antibody treatments, and antiviral drugs for COVID-19, there is still a dearth of evidence on the role of an individual's nutritional status on the severity of COVID-19. Objective: This study aimed to investigate the association between selenium (Se) and zinc (Zn) status and COVID-19 severity among individuals diagnosed with COVID-19 in North Carolina. Methods: Subjects (n = 106) were recruited remotely as part of the Nutrition and COVID-19 in North Carolina (NC-NC) study and filled out online screening questionnaires and dietary surveys. Toenail samples from 97 participants were analyzed to determine Se and Zn concentrations. To assess the severity of severe acute respiratory coronavirus (SARS-CoV)-2 infection, subjects were asked about the presence and duration of 10 commonly reported symptoms. These responses were used to calculate a COVID-19 severity index (CSI). The relationship between Se and Zn status (intake and toenail concentrations) and CSI was explored using a regression analysis. Results: Our results showed that the median (25th, 75th percentiles) dietary Se and Zn intake from selected food sources were 65.2 µg (43.2, 112.9) and 4.3 mg (1.8, 8), respectively. Headache, cough, loss of smell or taste, and fever were reported by at least half of the participants. In stepwise regression analysis, among individuals with low Se and Zn intake (below the median), Se intake was inversely associated with increasing CSI (ß = -0.66; 95% CI: -1.21, -0.11; P = 0.02). Conclusions: Findings from this study support a potential benefit of increasing the intake of dietary Se to mitigate the severity of SARS-CoV-2 infection.

Prevalence and Predictors of Low Breast Milk Iodine Concentration in Women Following Vegan, Vegetarian, and Omnivore Diets.

Purpose: Breast milk iodine concentration (BMIC) from vegan and vegetarian lactating mothers has not previously been evaluated. The goal of this study was to assess BMIC from vegans, vegetarians, and omnivores and to assess intake of iodine by breastfed infants. Materials and Methods: Breast milk samples from vegans (n = 12), vegetarians (n = 6), and omnivores (n = 12) living in the United States were analyzed. BMIC was determined at the mass-to-charge ratio (m/z) 127 by inductively coupled plasma mass spectrometry (ICP-MS) using an Agilent 8800 ICP-MS/MS (Agilent Technologies). Results: There was a significant difference in mean BMIC between participants following a plant-based diet (vegan and vegetarian, n = 18) compared with omnivores [4.42 versus 5.02 Ln(BMIC), respectively; p = 0.0405]. In linear regression to predict BMIC, vegan diet was a negative predictor (standardized ß = -0.409) and use of multi- or prenatal supplements was a positive predictor (standardized ß = 0.319). There were differences in the percentage of inadequate BMIC per maternal diet (75% vegan, 67% vegetarian, omnivore 58%) but this did not reach statistical significance. In 67% of the samples (20/30) BMIC was lower than the National Academy of Medicine's adequate intake (AI), assuming infant milk consumption of 0.78 L/day. Conclusions: Most samples from vegans and vegetarians contained a lower BMIC than AI for infants 0-6 months. Counseling of pregnant vegans and vegetarians should highlight importance of iodine supplementation during lactation. The findings are based on a small number of samples, especially for vegetarians, and thus, they need to be confirmed by larger studies.

Major and trace mineral composition of milk from lactating women following vegan, vegetarian and omnivore diets.

Approximately one-in-ten reproductive age adults in the USA follow a plant-based diet, yet there is limited information on the influence of vegan and vegetarian diets on the mineral composition of breast milk. This study explored the major and trace mineral composition in breast milk and associations with maternal diet patterns. We used a cross-sectional design to collect a single sample of breast milk from individuals following vegan (n 23), vegetarian (n 19) and omnivore (n 21) diet patterns. Plant-based diet (n 42) was defined as following either vegan or vegetarian diets. Sixteen minerals were assessed using inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Data were evaluated using traditional statistical techniques and five different machine learning approaches. The distribution of Se (median; quartile 1 and 3) was significantly different between groups (vegetarians 21, 18-26 µg/l; vegans 19, 18-25 µg/l and omnivores 17, 14-20 µg/l; P = 0·007) using a Kruskal-Wallis test. Machine learning techniques also identified Se as a potential biomarker for differentiating breast milk by maternal diet pattern. Individuals following a plant-based diet generally had a lower BMI, higher breast milk Se and lower breast milk I and Fe concentrations compared with those following omnivore diets. This suggests that maternal dietary pattern (plant-based v. omnivore) may be helpful clinical information to consider when caring for the breast-feeding dyad, with the strongest evidence related to differences in Se concentration.

Fortified Donor Human Milk Frequently Does Not Meet Sodium Recommendations for the Preterm Infant.

We measured the sodium content of donor human milk (DHM) and calculated the estimated intake at a feeding volume of 160 mL/kg/day. The mean sodium content of unfortified DHM was 102.0 mg/L (4.4 mEq). Because <1% of bovine-fortified samples met the recommended sodium content, infants born preterm who are fed predominantly DHM likely require additional sodium.

What is known about human milk bank donors around the world: a systematic scoping review.

OBJECTIVE: The WHO recommends that low birth weight infants receive donor human milk (DHM) when mother's milk is not available. Systematic reviews have been published regarding clinical outcomes of infants receiving DHM, as well as the impact of pasteurisation on the composition of DHM; however, information about milk bank donors has not been systematically assessed. DESIGN: We conducted a systematic scoping review of original research articles about milk bank donors published before August 2020. SETTING: Globally. PARTICIPANTS: Donors to milk banks. RESULTS: A total of twenty-eight studies were included across a variety of geographies: the USA (n 8), Brazil (n 7), Spain (n 4), India (n 2), and single studies in France, Norway, Poland, Italy, Taiwan, Korea and China. Study variables were grouped into six main categories: Donor Demographics (n 19), Clinical Characteristics (n 20), Donor Experiences (n 16), Donation Patterns (n 16), Lifestyle Characteristics (n 4) and Lactation/Breast-feeding History (n 8). Some demographic characteristics were commonly reported across regions, while other, including gender and race, were infrequently explored. Factors that might influence the composition of DHM, including birth timing (term or pre-term), milk type (colostrum, transition or mature) and maternal diet were not regularly studied. Other gaps in the literature included (1) donors' motivations and barriers to donation, (2) lactation and breast-feeding history, including factors that influence donors to pump and amass surplus milk, and (3) donation patterns, including whether donors are also selling milk to corporations or sharing milk with peers. CONCLUSION: What is known about milk bank donors in different geographies is often limited to a single study, with heterogeneity in the variables reported.

A Cross-Sectional Assessment of Human Milk Oligosaccharide Composition of Vegan, Vegetarian, and Nonvegetarian Mothers.

Purpose: Recently, maternal nutrient intake has been associated with human milk oligosaccharides (HMOs) composition. The goal of this study was to assess HMO composition in breast milk samples from vegan, vegetarian, and nonvegetarian lactating women. Second, we assessed impact of maternal body mass index (BMI), age, parity, and lactation stage on HMO composition. Materials and Methods: A cross-sectional analysis of HMO composition from vegan (n = 26), vegetarian (n = 22), and nonvegetarian (n = 26) lactating women was carried out. The majority of participants took dietary supplements. Results: In an unadjusted bivariate model, there was no difference in individual HMO composition, total HMO-bound fucose and HMO-bound sialic acid, or diversity and evenness scores by diet group. When adjusting for factors that significantly differed between groups (maternal BMI and lactation stage), no differences in HMO composition were observed. Secretor status was significant for 13 of the outcome variables with the strongest positive relationship with total HMO (ß = 0.922) and HMO-bound fucose (ß = 0.910), and the strongest negative relationship with sialyl-lacto-N-tetraose b (LSTb) (ß = -0.544). Lactation stage was significant for eight analytes, with the strongest positive impact on 3'sialyllactose (3'SL) (ß = 0.433), and the strongest negative impact on 6'sialyllactose (6'SL) (ß = -0.519). Maternal BMI had a significant positive relationship with total HMO composition (ß = 0.113) and 3'SL (ß = 0.325). Conclusions: Lactating women who consume plant-based diets do not produce different breast milk as it relates to HMO composition.

Nondiet Weight-Neutral Curricula Limited in Current Accredited US Dietetic Programs.

OBJECTIVE: Determine awareness and prevalence of, and interest in nondiet weight-neutral (NDWN) focused curriculum and factors associated with the presence in accredited dietetic programs throughout the US. METHODS: Online cross-sectional survey sent to directors of US Coordinated Programs (n = 60) and Didactic Programs in Dietetics (n = 214). RESULTS: 116 programs (42%) responded, 95% reported knowledge of NDWN approaches to weight management like Health at Every Size. Most schools (72%) included NDWN in their curriculum, mostly in a single lecture (53%). Most respondents (74%) reported interest in an NDWN curriculum. Common factors for not including NDWN were: lack of trained and knowledgeable staff (35%) and insufficient space in the curriculum to incorporate additional topics (35%). CONCLUSIONS AND IMPLICATIONS: Most knew of NDWN approaches and included in curricula but only as 1 lecture. Faculty training and curriculum flexibility may help support the increased incorporation of NDWN approaches.

Methods of mixing donor human milk during bottling results in fat differences between samples within a pool.

The influence of milk-banking processes on nutrients in donor human milk (DHM) is largely unknown. Previous studies have measured nutrients between pools of DHM, but within-pool nutrient differences (between bottles from the same pool) have yet to be elucidated. The objective of this study was to gain a better understanding of the effect of different mixing characteristics on the distribution of fat, protein, IgA, and lysozyme in bottled, raw DHM. Pools of DHM were created in a laboratory setting according to published human milk-banking guidelines and assigned to a mixing treatment (mixing during bottling method, pooling container material, and refrigerated hold time). Four mixing protocols using glass pooling containers and a 1-h refrigerated hold time were tested: control (no mixing during bottling); manual-A (Man-A, hand swirl after pouring 3 bottles); manual-B (Man-B, hand swirl after pouring every bottle); and mechanical-G (Mech-G, continuous stirring with a magnet). As secondary objectives, we compared the effect of a glass and a plastic pooling container with mechanical mixing (mechanical-P, Mech-P), and compared refrigerated delays of 1 and 24 h before bottling with manual mixing (manual-A24, Man-A24). To control for differences in nutrient content, comparisons between treatments were made using absolute percent difference from the treatment-specific mean; and comparisons within a treatment were made using the ratio of fat content in a bottle to fat content in the first bottle of the same pool. We did not observe differences in nutrient distribution between Man-A, Man-B, and Mech-G in pools held for 1 h, but all were significantly different from the control for fat. There were no differences between glass or plastic pooling containers when mechanical mixing was used. Holding a pool in the refrigerator for 24 h before bottling created significantly greater fat distribution than holding a pool for 1 h. Outcomes were the result of controlled experiments. In summary, manual and mechanical mixing of 1,700-mL DHM pools produces similar fat and protein distributions when DHM is pooled and bottled after a 1-h hold time. When DHM is held for 24 h before bottling, more research is needed to determine the duration of initial mixing needed to reduce fat variability between bottles.

Method for Removing Thawed Human Milk From a Plastic Storage Bag Impacts Fat Retention.

OBJECTIVES: Determine how thaw stage and bag manipulation (folding and squeezing) influence the retention of fat and number of aerobic bacteria colony-forming units when decanting human milk (HM) from plastic storage bags. METHODS: Lactating women (n = 40) in the Greensboro, North Carolina area were recruited to provide fresh HM. Samples were equally divided and frozen in storage bags for 2 months. Two thaw stages (ice/liquid) and the use of bag manipulation (yes/no) were assessed. Fat was measured using ether extraction and bacteria were measured using plate enumeration. Paired t tests were used to compare the effects of thaw stage and bag manipulation on post-thaw fat content. Repeated measures analysis of variance was used to compare the effect of bag manipulation on pre- and post-thaw bacteria. RESULTS: Fat retention was not significantly different when thawing to liquid versus ice (mean difference = 0.10 g/dL; n = 17 paired samples; P = 0.07). Decanting with bag manipulation retained more fat than decanting without manipulation, but only when HM was thawed to liquid (mean difference = 0.13 g/dL; n = 11 paired samples; P = 0.005), not when HM was thawed to ice (P = 0.47). Bag manipulation did not increase total aerobic bacteria for either thaw stage (P = 0.49). CONCLUSIONS: Fat retention is influenced by the method of removing previously frozen HM from plastic storage bags. Folding and squeezing the storage bag when decanting HM thawed to a liquid state increases fat recovery without increasing bacterial contamination.

Donor Human Milk Use in Populations Other than the Preterm Infant: A Systematic Scoping Review.

Introduction: Exclusive breastfeeding is recommended for an infant's first 6 months of life. If unable to breastfeed, expressed breast milk, including donor human milk (DHM), is recommended for optimal nutrition. Benefits of DHM in preterm infants have been established by extensive research. However, less is known about DHM use in other populations. Objective: To conduct a scoping review of the literature regarding DHM use in populations other than preterm infants. Materials and Methods: PubMed and Clinicaltrials.gov were used to search for articles and clinical trials published between January 1, 2000 and February 29, 2020. In total, 182 articles and reports were identified and screened by 2 independent reviewers. Results: Twenty-six articles met inclusion criteria and were reviewed. Studies were mostly observational in design and included infants born >35 weeks gestational age with health risks (9/26) and healthy infants (14/26). Most studies in infants with health risks (7/9) investigated clinical outcomes, with small, observational studies suggesting potential improvements in feeding tolerance and gastrointestinal health. Regarding healthy infants, no studies addressed growth, only one study measured clinical outcomes, and findings related to breastfeeding outcomes were conflicting. Over half of the studies reviewed (15/26) were not designed to establish a potential relationship between DHM use and relevant health-related outcomes. Conclusion: The current evidence of DHM use in populations other than preterm infants is limited by lack of direct health measures and infrequent use of randomized trials. More research is warranted to investigate clinical, growth, and breastfeeding outcomes.

National Prevalence of Donor Milk Use Among Level 1 Nurseries.

BACKGROUND AND OBJECTIVES: Donor milk use has increased among very preterm infants because of mounting evidence of health benefits; however, the extent that donor milk is used among healthy term infants in level 1 nurseries is unclear. We aimed to determine (1) national prevalence of and (2) hospital factors associated with donor milk use in level 1 nurseries. METHODS: Among 3040 US birthing hospitals, we randomly selected hospitals from each of 4 US regions (119 in northeast, 120 in Midwest, 116 in west, and 103 in south) for a total of 458 hospitals. We surveyed the nursing leaders of these hospitals from October to December 2017 regarding routine use of donor milk in the level 1 nursery (yes or no). To estimate national prevalence, we weighted responses according to the number of birthing hospitals within each region. We examined relationships between routine donor milk use in the level 1 nursery and hospital characteristics using multivariable logistic regression. RESULTS: In total, 214 of 458 (47%) nursing leaders responded. The national prevalence of routine donor milk use in level 1 nurseries was 17.6%. Eighty-five percent of donor milk programs were ≤5 years old. Donor milk use occurred more often in hospitals with ≥1500 annual births (41.7%), compared to ≤500 annual births (6.3%) (adjusted odds ratio 7.8; 95% confidence interval 1.8-34.4), and in the west (30.9%), compared to the northeast (10.5%) (adjusted odds ratio 4.1; 95% confidence interval [1.1-14.9]). CONCLUSIONS: Although there is limited evidence to support donor milk for healthy infants in the nursery, nearly one-fifth of level 1 US nurseries routinely used donor milk in 2017.