Current trends in research on human milk exchange for infant feeding

Breastfeeding is critical for the healthy growth and development of infants. A diverse range of infant-feeding methods are used around the world today. Many methods involve feeding infants with expressed human milk obtained through human milk exchange. Human milk exchange includes human milk banking, human milk sharing, and markets in which human milk may be purchased or sold by individuals or commercial entities. In this review, we examine peer-reviewed scholarly literature pertaining to human milk exchange in the social sciences and basic human milk sciences. We also examine current position and policy statements for human milk sharing. Our review highlights areas in need of future research. This review is a valuable resource for healthcare professionals and others who provide evidence-based care to families about infant feeding

A mixed-methods observational study of human milk sharing communities on Facebook

Objectives: The Food and Drug Administration discourages the casual sharing of human milk because of the risk of pathogen transmission. No information is currently available on the prevalence of this practice. The purpose of this mixed-methods observational study is to describe the size and activity of online milk sharing communities. Materials and Methods: Data for 3 months were extracted from nine public Facebook pages that facilitate the exchange of human milk. The numbers of participants, interactions, and comments were analyzed. Results: We observed 954 individuals participating in milk sharing. The number of interactions per individual ranged from none to 16 (mean, 1.74±1.65). Top reasons that participants requested milk included “lactation problems” (69.4%) and “child health problems” (48.5%). Nearly half of donors were offering 100 ounces or more, which is the minimum to be eligible to donate to nonprofit milk banks. Conclusions: Milk sharing networks in the United States are active, with thousands of individuals participating in the direct exchange of raw human milk. Public health issues include increasing the supply of pasteurized donor milk for fragile infants, increasing breastfeeding support, and helping milk sharing families appropriately manage risks

The effects of fortification and refrigerated storage on bioactive proteins in Holder-pasteurized donor human milk

Objective: The aim of the study was to assess the total protein, lysozyme, and immunoglobulin A (IgA) content of unfortified and fortified Holder-pasteurized donor human milk (HPDHM) during 96 hours of refrigerated storage. Study Design: HPDHM was prepared in a hospital feeding room and subjected to treatment with 3 different fortifiers: an acidic, bovine-based (F-ACID), a neutral, bovine-based, and a human milk–derived (F-HUM) fortifier. Unfortified HPDHM served as the control (CONTROL). Samples were stored at 4°C, and every 24 hours, a 1-mL aliquot was removed for analysis. Results: At baseline, there was a significant difference in protein (mean, standard deviation) concentration (g/dL) between control (1.3, 0.1) and all other treatments (F-ACID = 2.0, 0.2; neutral, bovine-derived fortifier = 2.2, 0.1; F-HUM = 2.5, 0.1; P 0.9) for all dependent variables. Conclusion: The type of fortifier has a more significant impact on bioactive components in fortified HPDHM than does storage time. Our findings of lack of negative impact of refrigeration storage time on the protein and bioactive components of donor milk strengthen the recent recommendations to extend storage time to 48 hours

Storage of unfed and leftover pasteurized human milk

Objective: To determine the impact of storage on bacterial growth and immunological activity of pasteurized human milk and leftover pasteurized human milk that has been exposed to the microflora in an infant's mouth. Materials and Methods: Eighteen mother-infant dyads participated in two separate studies. Mother's milk was pasteurized, and each baby was fed 1 to 2 ounces. Pasteurized and leftover pasteurized milk were stored at room (24°C) and refrigerated temperatures (4°C). After storage, milk was analyzed for bacteria, total protein, lysozyme activity, and secretory immunoglobulin A (SIgA) activity. Results: In pasteurized and leftover pasteurized milk stored in the refrigerator for 7 days, total aerobic bacteria do not increase significantly and total protein and bioactive proteins are stable. At room temperature, there is a significant increase in total aerobic bacteria in leftover pasteurized milk during 12 hours of storage (p?<?0.01) and a significant decrease in total protein and SIgA activity in pasteurized milk during 12 hours of storage (p?=?0.02 and p?=?0.03, respectively). Conclusions: When stored in the refrigerator, pasteurized and leftover pasteurized milk may be stored for at least 7 days when considering the variables studied. Caution should be used when storing pasteurized and leftover pasteurized milk at room temperature to prevent an increase in bacterial growth and a decrease in total protein and SIgA activity

A Pilot Study on the Protein Composition of Induced Nonpuerperal Human Milk. Journal of Human Lactation

Background: Our understanding of the components of human puerperal milk is extensive and increasing, yet the literature on nonpuerperal human milk has been limited to studies that measure the success of induced lactation. Objective: This study aimed to describe the composition of total protein and key bioactive proteins when lactation is induced in nonpuerperal women. Methods: Two women who induced lactation in the absence of pregnancy provided weekly milk samples over a 2-month period for analysis of total protein, secretory immunoglobulin A (sIgA), lysozyme, and lactoferrin. Composition was compared to the mature milk of 3 puerperal control subjects who were 11 months postpartum. Results: Median total protein for subject A was 2.30 g/dL (interquartile range [IQR] = 0.46) and showed a significant downward trend over time (P < .0001), whereas the median total protein for subject B was 2.21 g/dL (IQR = 0.18) and showed a nonsignificant decline (P = .232). Total protein in both nonpuerperal subjects was elevated compared to control subjects. Secretory IgA activity declined for both nonpuerperal subjects over time, whereas lysozyme concentrations increased over time. Both sIgA and lysozyme approached the levels seen in the puerperal controls. Lactoferrin levels remained stable for both nonpuerperal subjects and were elevated compared to puerperal milk samples. Conclusion: This pilot study suggests that nonpuerperal milk has similar or higher levels of total protein, sIgA, lactoferrin, and lysozyme compared to puerperal, mature milk at 11 months postpartum, which warrants more attention as adoptive mothers increasingly choose to induce lactation

The Nutritive and Immunoprotective Quality of Human Milk beyond 1 Year Postpartum: Are Lactation-Duration-Based Donor Exclusions Justified?

Donor human milk is critical for the fragile preterm infant who does not have access to his or her mother’s milk, improving survival rates and quality of survival and decreasing hospital stay. Despite the opening of donor milk banks around the world, shortages continue as demand for donor milk exceeds supply. One potential means of increasing supply is by reducing exclusion criteria that prohibit mothers from donating milk based on duration of lactation. Minimal research has been done on the composition of human milk during the second year of lactation, with most research focusing on the nutritive compounds and not the immunoprotective compounds. Several immunoprotective compounds, including lysozyme, lactoferrin, secretory immunoglobulin A, and oligosaccharides, are abundant in human milk compared to bovine-based infant formula and are partially or fully retained during Holder pasteurization, making them an important differentiating feature of donor milk. A PubMed search was conducted to review studies in human milk composition during the second year of lactation. Limitations of existing research include sample collection protocols, small study sizes, and use of populations that may have been at risk for nutritional deficiencies. Stable concentrations of several components were reported including protein, lactose, iron, copper, lactoferrin, and secretory immunoglobulin A. Lysozyme concentration increased during extended lactation, while zinc and calcium concentrations declined into the second year. Conflicting findings were reported on fat content, and no information was available regarding oligosaccharide content. More research is needed to create evidence-based guidelines regarding the nutritive and immunoprotective value of donor milk throughout the course of lactation

Total water-soluble choline concentration does not differ in milk from vegan, vegetarian, and non-vegetarian lactating women

Background: Choline is an essential nutrient for brain growth and other processes in the developing neonate. The impact of a maternal plant-based diet on the choline composition of breast milk is unknown. Objective: We assessed the water-soluble choline content of milk from lactating women in the United States following 3 dietary patterns: vegan, vegetarian, and nonvegetarian. Methods: We conducted a cross-sectional study of 74 healthy lactating women who provided a single breast-milk sample using a standardized collection protocol. Participants completed a food-frequency screener and were classified as follows: nonvegetarians (NONVEG) consumed meat; vegetarians (VEGT) consumed milk, dairy, and/or fish; and vegans (VEGAN) consumed animal products less than monthly. Primary outcomes measured were the concentration (in milligrams per liter) and distribution (percentage) of choline from the following water-soluble forms: free choline, phosphocholine (PCho), and glycerophosphocholine (GPC). Differences between diet groups were evaluated with ANOVA. Results: There was a wide range in breast-milk total water-soluble choline (4–301 mg/L), with no significant difference (P > 0.05) by maternal diet pattern. There were differences in choline forms, with VEGAN having a greater mean ± SD concentration and distribution of choline derived from GPC (62.7 ± 25.3 mg/L) than VEGT (47.7 ± 21.2 mg/L) and NONVEG (42.4 ± 14.9 mg/L) (P = 0.0052). There was a lower mean ± SD percentage of choline from PCho (P = 0.0106) in VEGAN (32.5% ± 18.3%) than in VEGT (46.1% ± 18.3%) and NONVEG (44.8% ± 15.7%). Lactation stage and maternal BMI were significantly associated with some choline forms. Conclusions: There was a wide range of water-soluble choline concentrations in the milk of healthy lactating women following vegan, vegetarian, and nonvegetarian diets, with no observed difference in total water-soluble choline concentration by maternal diet. This suggests that maternal plant-based diet by itself is not a risk factor for low breast-milk choline

The effects of refrigerated and frozen storage on Holder pasteurized donor human milk: A systematic review

Background: Pasteurized donor human milk (PDHM) is the recommended feeding alternative for preterm infants when mother's own milk is not available. Use of PDHM in United States neonatal hospitals is increasing, although guidelines for the refrigerated and frozen storage are limited. Objective: We aimed to review the current evidence for the storage of Holder PDHM (HPDHM) under refrigerated and frozen storage conditions. Methods: A systematic review of the literature was conducted for studies published between 1985 and May 2018. Studies were included if they studied the storage of Holder-pasteurized human milk under refrigerated or frozen storage conditions. Results: Fourteen studies met the inclusion criteria. Five studies addressed refrigerated storage and nine studies addressed frozen storage. There was little overlap in the outcomes measured or the analytical methods employed. There was concordance in three studies reporting no microbial growth over 4–9 days of refrigerated storage, and in five studies reporting a reduction in fat during 1–8 months of frozen storage. Only one study assessed the storage of HPDHM that had been fortified. Conclusions: Long-term refrigerated and frozen storage of HPDHM affects some components in milk more than others. While there is evidence of microbial purity during four or more days of refrigerated storage in clinical conditions, there is limited research on the impact of macro and micronutrients, or the impact of fortifiers. More research is needed in these areas

Donor human milk and fortifier use in United States level 2, 3, and 4 neonatal care hospitals

Objective: In 2011, the United States Surgeon General issued a call to action to “identify and address obstacles to greater availability of safe banked donor milk for fragile infants.” The purpose of the present study is to analyze patterns in donor human milk (DHM) and fortifier use in level 2, 3, and 4 neonatal facilities in 2015 and to identify factors associated with nonuse. Methods: Data from the 2015 Maternity Practices in Infant Nutrition and Care survey, conducted by the Center for Disease Control and Prevention, were analyzed for questions about feeding practices within neonatal hospitals. Results: The percentage of neonatal facilities that reported using DHM in 2015 was 38.3%, up 74% from 2011. The majority of level 3 and level 4 facilities reported using DHM (65.7% and 73.3%, respectively) and fortifiers (96.1% and 91.9%, respectively). Within DHM-using facilities, a wide range of DHM feeding patterns was reported. The prevalence of DHM use was higher in facilities that had the highest rates of mother's own milk feedings (P < 0.001), in facilities that were participating in the Baby Friendly Hospital Initiative (P < 0.001), and in facilities that were in a state with an operating milk bank (P < 0.001). Conclusions: DHM use continues to increase in advanced care neonatal settings, with significant difference based on acuity level, facility size, breast-feeding culture, and proximity to a milk bank. Geographic gaps in DHM use provide the opportunity for targeted efforts to improve access

Vitamin B12 content in breast milk of vegan, vegetarian, and non-vegetarian lactating women in the United States

Background: The nutritional profile of human milk varies significantly between women, and the impact of maternal diet on these variations is not well understood. Objective: We analyzed breast-milk vitamin B-12 concentration and vitamin B-12 supplement use pattern among women who adhered to different dietary patterns: vegan, vegetarian, and nonvegetarian. Design: A total of 74 milk samples, 26 from vegan, 22 from vegetarian, and 26 from nonvegetarian breastfeeding mothers, were analyzed. Results: The prevalences of low vitamin B-12 ( 0.05). Conclusions: Almost 20% of our study participants were classified as having low breast-milk vitamin B-12 concentrations (<310 pmol/L), independent of maternal diet pattern. Approximately 85% of participants categorized as having low vitamin B-12 were taking vitamin B-12 supplements at doses in excess of the Recommended Dietary Allowance, which suggests that more research is needed to determine breast-milk adequacy values