Human milk has a protective effect for premature infants who
are at risk of necrotizing enterocolitis and sepsis, two medical
conditions associated with high rates of mortality. Milk banks
collect, screen, store, process, and distribute human milk when
needed. The strict quality control procedures followed by milk
banks ensure the safety of donor milk while retaining many of
the beneficial effects of raw human milk.
There are many circumstances where milk from the infant’s
own mother is not available or sufficient. Milk banks function
as repositories of donated milk. The most common practice is
to pool milk from multiple donors, in order to ensure an even
distribution of nutrients such as protein and fat. Donated milk
is often pasteurized using the Holder process and frozen for up
to 1 year. This method of pasteurization offers a good compromise
between microbiological safety and biological quality.
The typical milk donor is of average childbearing age, with a
milk supply large enough to allow milk donation while meeting
her own infant’s needs. Donors are screened for general health,
including for recreational drug use and infectious diseases such
as viruses and syphilis.
Premature infants represent the largest group of recipients of
donor milk. Due to their high risk of infection and necrotizing
enterocolitis, premature infants also derive the greatest benefits
from receiving human milk. Worldwide, there is growing
interest in human milk banking, with efforts to introduce milk
banks even in third world regions. Guidelines from international
pediatric societies indicate that if the mother’s own milk
is not available, donor milk should be the next choice. Human
milk should be stored in established banks that adhere to strict
Arslanoglu S, et al; ESPGHAN Committee on Nutrition: Donor
human milk for preterm infants: current evidence and research
directions. J Pediatr Gastroenterol Nutr 2013;57:535–542.
Donor milk from human milk banks is essential for
premature and sick infants.
Milk banks strictly follow guidelines for the storage,
processing, and handling of human milk to ensure the
safety of donor milk.
Pasteurized donor milk retains many of the beneficial
health effects of raw human milk.
Human milk banks play an essential role by providing human
milk to infants who would otherwise not be able to receive
human milk. The largest group of recipients are premature
infants who derive very substantial benefits from it. Human
milk protects premature infants from necrotizing enterocolitis
and from sepsis, two devastating medical conditions.
Milk banks collect, screen, store, process, and distribute human
milk. Donating women usually nurse their own infants
and have a milk supply that exceeds their own infants’ needs.
Donor women are carefully selected and are screened for
HIV-1, HIV-2, human T-cell leukemia virus 1 and 2, hepatitis
B, hepatitis C, and syphilis. In the milk bank, handling, storing,
processing, pooling, and bacterial screening follow
standardized algorithms. Heat treatment of human milk diminishes
anti-infective properties, cellular components,
growth factors, and nutrients. However, the beneficial effects
of donor milk remain significant and donor milk is still
highly preferable in comparison to formula.
It is probably not widely appreciated that human milk
banking is an absolute necessity if all infants are to enjoy
the benefits of human milk. This is so because a substantial
number of infants, especially premature infants, are
unable to receive adequate amounts of their mothers’
milk for a variety of reasons. Were it not for milk banks,
these infants could not be fed human milk and would suffer
the consequences. Premature infants derive very important
protections from human milk.
Unfortunately, there are circumstances where milk
from the infant’s own mother is not available. Milk donated
by other women (donor milk) must then fill the
gap. Premature infants constitute the largest and most
important group of infants where milk from other women
is needed because their own mothers’ milk is not available
or is not available in sufficient quantity. Human milk
banks collect, screen, pasteurize, and distribute donated
breast milk to hospitals or outpatient recipients  . Usually
the collection, storage, and processing in a human
milk bank follows established guidelines. Milk banks are
by far the most important providers of donor milk, the
fact not withstanding that other venues of milk donation
are also used.
The first human milk bank was founded in 1909 in
Vienna, Austria. Wet nursing was widely practiced in Europe
during the 19th century in order to provide human
milk for infants whose mothers were unable to provide
milk for their infants. However, wet nurses were not always
available or, when available, pursued unhealthy lifestyles
or carried infections that could be transmitted
through milk. An alternative to wet nursing was found in
human milk banking.
Shortly after Vienna, the first milk bank opened in the
United States in the Boston Floating Hospital and many
others followed all over the world. In the 1960s, efforts in
human milk banking faded due to advances in neonatal
medical care and infant nutrition, mainly the development
of high-quality infant formulas. In the 1980s, the
new infectious disease, HIV, arrived. As it is transmissible
through breast milk, this led to the closing of many milk
banks. Once disease transmission via human milk was
recognized as a health hazard, serological testing of the
mother became necessary. The added financial burden
drove some milk banks out of business. Appropriate
screening of donating mothers as well as adherence to
standards of procedure have reversed that trend since the
Milk banking activity varies greatly between different
parts of the world due to a variety of reasons: sometimes
the reasons have to do with economics and funding, and
sometimes they are linked to religious and cultural factors.
Globally, there is an increase of interest in milk
banking all over the world. Currently there is a move to
open many milk banks in India and other Asian countries
such as Vietnam, China, and Japan. The increase of interest
goes along with the recommendations of large pediatric
societies, such as ABM, ESPHGAN, and AAP, to promote
human milk feeding in premature infants [2–4]. All
guidelines say that the mother’s own milk is the first
choice for an infant. However, if the mother’s own milk
is not available, donor milk is the recommended alternative.
A further important recommendation is that donor
human milk should be provided by an established human
milk bank that follows standard safety guidelines.
Table 1 gives an overview about the established and
planned milk banks all over the world.
Why Is Human Milk Being Banked?
The main function of milk banks is to serve as repositories
of donated milk so it is available when needed. Milk
banks receive milk from donors, process it, and store it
until used. Most commonly milk from multiple donors is
pooled, although some banks pool milk only of individual
donors (single-donor banks). Usually, milk provided
by milk banks has undergone pasteurization. Once pasteurized,
milk is placed in small (100–150 mL) containers
and is stored frozen for up to 1 year depending on local
guidelines. In the US, milk banks charge a processing fee
to cover the costs of collecting and handling of the milk.
The type of container affects the stability of the constituents
of human milk, while colostrum was reported to remain
stable when refrigerated for 24 h in any container
(Table 2) .
Who Are the Milk Donors?
Most milk is donated by women, who have nursed
their own infant for some time and realize that their milk
supply is large enough to allow them to donate milk while
still satisfying their own infant’s needs. A study from
France  showed that the typical donating mother was
of average childbearing age with strong support at home.
Almost half did not work outside of the home, and a large
number were from the health and social services fields.
Reasons for donation were largely altruistic, and a general
optimistic attitude prevailed within the mothers.
To be eligible as milk donors, women must not be using
recreational or other drugs, and their physician as well
as the infant’s physician must agree that milk donation is
in order. The milk bank will obtain a health history and
obtain blood for testing. Usually, the donating mother is
screened for HIV-1, HIV-2, human T-cell leukemia virus
1 and 2, hepatitis B, hepatitis C, and syphilis . If all requirements
are met, the donor is provided a supply of
milk containers and receives instruction as to the appropriate
means of milk expression. The donor obtains milk
by mechanical pump or manual expression and stores it
in the freezer compartment of their home refrigerator before
delivery to the milk bank. The milk is transported to
the milk bank either by the mother herself or by a transport
service provided by the milk bank. It is important
that the cooling chain is never interrupted; therefore, special
special cooling bags or cooling boxes have to be used during
transportation from home to the milk bank.
Milk donation is an act of unselfishness. In most countries
donors receive no compensation, but in some countries
donors receive modest monetary compensation for
actual costs incurred. It represents mostly a token of appreciation.
How Is Milk Handled by the Bank?
Milk banks generally follow standardized procedures
for the collection and handling of donated milk . Donors
are instructed by the milk bank about recommended
breast cleaning and breast pumping procedures. The
bank provides containers for milk. Pooling of milk from
several pumpings is often performed. Each container
must carry the name, date, and time of expression. The
milk remains in the freezer until it is delivered to the
bank. Figure 1 shows the human milk banking process.
At the bank, milk is stored at –20 ° C. On the day before
processing, the donated milk is placed in a refrigerator for
overnight thawing. On the day of pasteurization, the milk
from 3–5 donors is pooled. Pooling serves the purpose of
distributing nutrients, such as protein and fat, as well as
foreign substances evenly. After pooling, the milk is
placed in individual 100 mL bottles. Pasteurization is carried
out in a water bath at 62.5 ° C for 30 min followed by
rapid cooling. Milk bottles are then stored at –20 ° C until
use of the milk. This method (Holder pasteurization) is
widely felt to represent a good compromise between microbiological
safety and nutritional/biological quality of
donor milk  Nevertheless, methods that lead to less
nutrient loss and, perhaps, are less time consuming would
be desirable and are being sought .
High-temperature short-time pasteurization at 72°C
for 5–15 s is such a method. It reaches a better compromise
between microbiological safety and nutritional and biological quality of donor milk [10–13].
The method is not yet used routinely due to lack of
The combination of ultrasound and heat (thermoultrasonic
treatment) is an emerging technique that allows
milk to retain more of its bioactive components compared
with thermal pasteurization . However, the
current experimental system is limited to small volumes
and needs to be scaled up.
High-pressure processing (HPP) shows promise as an
alternative to pasteurization. Total immunoglobulin A
immunoreactivity and lysozyme activity are significantly
higher after HPP compared with pasteurization
. Besides, HPP is faster and probably more convenient
than Holder pasteurization. It seems a promising
technology, but further investigation is necessary before
it can be used routinely.
Finally, there is Ohmic heating, a new technology under
investigation. Ohmic treatment is a thermal processing
method wherein the food material, which
serves as an electric resistor, is heated by passing an
electric current through it, which leads to rapid and
uniform heating. Like thermal processing, Ohmic
heating inactivates microorganisms by heat. The first
experimental trials have shown no modification of the
protein pattern of milk at a temperature of 72°C and
only small changes at a temperature of 78°C.
In some countries, the milk is tested bacteriologically
before it is pasteurized, in some countries after pasteurization,
and in others the milk is tested before and after pasteurization.
Some countries, such as Norway, have a tradition
of feeding raw donor milk. In Norwegian milk banks,
each container of milk from a donor is screened for bacteria.
Milk that contains any pathogens or high counts
(>100,000 colony-forming units/mL) of any other bacteria
is destroyed. Milk with a low bacterial count (<10,000
colony-forming units/mL) is used for the smallest preterm
babies . Ronnestad et al.  described an incidence
of late-onset sepsis in a Norwegian cohort of extremely
low-birth-weight infants receiving raw breast milk or donor
milk of 19.8% (80/405), which was similar to the incidence
in the Vermont Oxford quality network (21.4%, in
the year 2000). Therefore, it is unlikely that microbiologically
screened raw milk is hazardous for preterm infants.
Who Are the Recipients of Donor Milk?
The most common recipients of donor milk are the
Premature infants, especially infants with a birth
weight below 1,500 g, because of their high risk of infection
and necrotizing enterocolitis
Infants with gastrointestinal anomalies undergoing
gastrointestinal surgery leading to short bowel syndrome
When the mother is temporarily unable to nourish her
infant completely, e.g. when the mother is ill or hospitalized
Weaning from parenteral nutrition
Metabolic disorders, especially amino acid disorders
Before the mother’s own milk comes in (first few days
Premature infants are not only the largest group of recipients
of donor milk, they are also those who derive by
far the greatest benefits from receiving human milk. Human
milk exerts strong trophic effects on the infant gut
and thereby enables full enteral feedings to be reached
earlier than without human milk . Human milk protects
premature infants strongly against necrotizing enterocolitis
[19, 20] and against sepsis , two conditions
that carry high mortalities. Some mothers object intuitively
to the use of donor milk, which is why donor milk
is fed only after its source has been explained to the mother
and she has agreed to its use.
The reason why mothers of premature infants are often
not able to provide milk at all or provide milk only in
insufficient quantity is that premature delivery, by shortening
pregnancy, foreshortens the period of preparatory
lactogenesis. Also, the necessary mechanical milk expression
is less effective in stimulating and maintaining milk
production than suckling by a mature infant.
It has been suggested that the availability of donor milk
could act as a disincentive to mothers to provide milk for
their premature infants. There are indeed data in the literature
that support this contention . However, a 1-
year study in 2010 involving all NICUs in Italy showed
that the rate of exclusive breastfeeding at the time of discharge
was significantly higher in NICUs with milk banks
than in NICUs without milk banks (29.6 vs. 16.0%) .
This confirms anecdotal reports from other areas. It appears
thus that the availability of donor milk has a positive
effect on the motivation of mothers to provide milk for
Donor milk is also fed to older babies and to children
with a variety of medical conditions, including severe
food allergy or feeding intolerance, growth failure while
on formula, intractable rotavirus enteritis, and during
chemotherapy for cancer . Occasionally, adopted infants
receive donor milk. Furthermore, there are several
case reports where donor milk was used in adults with
special medical conditions, e.g. in liver transplanted patients
who were IgA deficient to supply extra IgA  or
in adult cancer patients .
The Composition of Donor Milk
It is widely appreciated that the composition, in particular
the protein and fat content, of individual expressions
of human milk varies greatly. This has led to the
promotion of bedside human milk analyzers and procedures
for nutrient fortification of individual milk samples.
However, with donor milk the variability of composition
is greatly reduced due to pooling. Milk from multiple
pumpings is usually pooled by the donor mother
before delivery to the bank. Pooling of milk from multiple
donors is then performed by the milk bank, with the result
that the protein and fat content of pooled milk is quite
stable and predictable. Michaelsen et al.  reported
that fat and protein concentration vary widely from sample
to sample but that variability decreases sharply with
pooling of samples from multiple donors. At the Mother’s
Milk Bank of Iowa, the nutrient content of 37 milk pools
collected over a period of 2 years (2003–2005) was analyzed.
The (true) protein concentration averaged 8.22 g/L
with an SD of 0.59 g/L, and the fat content averaged 39.0
g/L with an SD of 3.51 g/L. The variability of composition
is thus far lower than that between individual samples
. Low variability is of particular advantage in the case
of premature infants because variability of the protein
content is often the source of concerns about inordinately
high intakes of protein. Low variability of composition
of donor milk has the advantage that the infant’s nutrient
intake varies little from feeding to feeding and is essentially
always known, whereas with the mother’s own milk
the nutrient content may vary greatly from feeding to
Is Donor Milk as Good as Mother’s Milk?
The fact that, with some exceptions, donor milk undergoes
pasteurization has led to concerns that some or
all of the protective effects of human milk may be lost.
Studies assessing milk components before and after pasteurization
have documented that indeed several important
components of human milk are reduced in concentration
or are eliminated altogether, as summarized in
Table 3. Heat treatment affects anti-infective and cellular
components, growth factors, and some nutrients, depending
on the heat and duration of exposure. Enzymes
are most heat-sensitive while immune components are
compromised but not completely destroyed.
Processing of human milk also affects unsaturated fatty
acids  and damages the membrane of milk fat globules
. Human milk contains stem cells with multilineage
properties and variable expression of pluripotency
genes normally found in human embryonic stem cells
. It is likely that these stem cells are destroyed during
heat treatment. On the other hand, some important protective
components such as the oligosaccharides are essentially
resistant to the effects of heat.
Given these effects of high-temperature processing, it
would be expected that the protective effects of human
milk might be diminished but not abolished altogether.
That is exactly what the literature shows. In 5 trials comparing
formula with donor milk with regard to the incidence
of necrotizing enterocolitis, the risk of necrotizing
enterocolitis was nonsignificantly diminished in each trial.
However, collectively, the 5 trials showed a significant
protective effect of donor milk compared to formula
(Fig. 2) 
A direct comparison of fresh against pasteurized human
milk performed by Narayanan et al.  showed a
somewhat reduced protective effect against infection
(14.3 vs. 10.5% infection) which was still much stronger
than the effect of formula (33.3% infection). It is thus evident
that the beneficial effects of pasteurized human
milk are diminished vis-à-vis fresh milk but that enough
of the protective effects remain to render donor milk the
feeding of choice for premature infants in the absence of
any or sufficient maternal breastmilk.
Is Donor Milk Safe?
Because of the potential for transmission of disease
pathogens, sometimes there are concerns about this possibility.
With current donor screening and pasteurization
of donor milk, the possibility of disease transmission is
infinitesimally small. In fact, there is not a single case of
documented disease transmission through banked donor
milk in recent decades. Whether that can also be said
about informal milk exchanges is not known.
Is Donor Milk Cost-Effective?
Because milk banks charge a processing fee ($6–7/100
mL donor milk), it has been asked whether the benefits
accruing to the infants justify the expense. Although it is
inappropriate to ask this question in relation to deadly
conditions (necrotizing enterocolitis, sepsis), fortunately
several studies have documented that the use of donor
milk is cost-effective [34, 35]. Thus, the use of donor milk
not only saves lives, it also saves the hospital money. It
was reported that sometimes mothers buy breast milk for
their premature or sick infants via the internet, social networks
, from friends, from private providers, or in
other informal sharing arrangements. In those cases, donor
screening, quality control of the human milk, and
shipping standards are missing. This behavior is risky and
is not recommended.
All donor milk must be fortified with nutrients before
it is fed to premature infants. In this regard, donor milk
does not differ from the mother’s own milk. Most human
milk fortifiers contain as protein source various fractions
or derivatives of cow milk. One fortifier provides protein
from human milk and is claimed to protect better against
necrotizing enterocolitis than fortifiers containing bovine
milk proteins, although evidence for that effect is
lacking . The lack of benefit, therefore, argues against
use of the high-cost human milk-based fortifier.
Milk banks serve a vital function by providing human
milk for premature infants who, for a variety of reasons,
would otherwise not have access to human milk. As human
milk confers major protective effects to premature
infants, the availability of human milk is an important
quality of care issue. The use of donor milk is widely endorsed
[4, 38, 39].
We thank Gillian Weaver, head of the European milk banking
association EMBA, for her valuable input.
The authors declare that no financial or other conflict of interest
exists in relation to the contents of this article. The writing
of this article was supported by Nestlé Nutrition Institute.
Arnold LDW: Human Milk in the NICU:
Policy into Practice. Ontario, Jones and
Bartlett Publishers, 2010.
Arslanoglu S, et al; ESPGHAN Committee
on Nutrition: Donor human milk for preterm
infants: current evidence and research
directions. J Pediatr Gastroenterol Nutr
2013; 57: 535–542.
The Academy of Breastfeeding Medicine:
ABM Clinical Protocol #10: Breastfeeding
the late preterm infant (34 0/7 to 36 6/7 weeks
gestation) (first revision June 2011). Breastfeed
Med 2011; 6: 151–156.
Eidelman AI, Schanler RJ: Breastfeeding and
the use of human milk. Pediatrics 2012; 129:
Goldblum RM, et al: Human milk banking.
II. Relative stability of immunologic factors
in stored colostrum. Acta Paediatr Scand
1982; 71: 143–144.
Azema E, Callahan S: Breast milk donors in
France: a portrait of the typical donor and
the utility of milk banking in the French
breastfeeding context. J Hum Lact 2003; 19:
Human Milk Banking Association of North
America (HMBANA): Guidelines for the Establishment
and Operation of a Donor Human
Milk Bank, 2015.
Moro GE, Arslanoglu S: Heat treatment of
human milk. J Pediatr Gastroenterol Nutr
2012; 54: 165–166.
Moro GE: V. Processing of donor human
milk. J Pediatr Gastroenterol Nutr 2015;
Goldblum RM, et al: Rapid high-temperature
treatment of human milk. J Pediatr
1984; 104: 380–385.
Hamprecht K, et al: Cytomegalovirus (CMV)
inactivation in breast milk: reassessment of
pasteurization and freeze-thawing. Pediatr
Res 2004; 56: 529–535.
Arslanoglu S, et al: Guidelines for the establishment
and operation of a donor human
milk bank. J Matern Fetal Neonatal Med
2010; 23(suppl 2):1–20.
Baro C, et al: Effect of two pasteurization
methods on the protein content of human
milk. Front Biosci (Elite Ed) 2011; 3: 818–829.
Czank C, Simmer K, Hartmann PE: Simultaneous
pasteurization and homogenization
of human milk by combining heat and ultrasound:
effect on milk quality. J Dairy Res
2010; 77: 183–189.
Permanyer M, et al: Maintenance of breast
milk Immunoglobulin A after high-pressure
processing. J Dairy Sci 2010; 93: 877–883.
Grøvslien AH, Grønn M: Donor milk banking
and breastfeeding in Norway. J Hum Lact
2009; 25: 206–210.
Ronnestad A, et al: Late-onset septicemia in
a Norwegian national cohort of extremely
premature infants receiving very early full
human milk feeding. Pediatrics 2005; 115:
Lawrence RA, Lawrence RM: Breastfeeding:
A Guide for the Medical Profession, ed 7.
Missouri, Elsevier, 2010.
Schanler RJ, Shulman RJ, Lau C: Feeding
strategies for premature infants: beneficial
outcomes of feeding fortified human milk
versus preterm formula. Pediatrics 1999; 103:
Meinzen-Derr J, et al: Role of human milk in
extremely low birth weight infants’ risk of
necrotizing enterocolitis or death. J Perinatol
2009; 29: 57–62.
Patel AL, et al: Impact of early human milk
on sepsis and health-care costs in very low
birth weight infants. J Perinatol 2013; 33: 514–
Davanzo R, et al: Breastfeeding at NICU discharge:
a multicenter Italian study. J Hum
Lact 2013; 29: 374–380.
Arslanoglu S, et al: Presence of human milk
bank is associated with elevated rate of exclusive
breastfeeding in VLBW infants. J Perinat
Med 2013; 41: 129–131.
Tully MR: A year of remarkable growth for
donor milk banking in North America. J Hum
Lact 2000; 16: 235–236.
Merhav HJ, et al: Treatment of IgA deficiency
in liver transplant recipients with human
breast milk. Transpl Int 1995; 8: 327–329.
Rough SM, et al: Qualitative analysis of cancer
patients’ experiences using donated human
milk. J Hum Lact 2009; 25: 211–219.
Michaelsen KF, et al: Variation in macronutrients
in human bank milk: influencing factors
and implications for human milk banking.
J Pediatr Gastroenterol Nutr 1990; 11:
Cooper AR, et al: Macronutrient content of
donor human breast milk. Arch Dis Child
Fetal Neonatal Ed 2013; 98:F539–F541.
Lavine M, Clark RM: Changing patterns of
free fatty acids in breast milk during storage.
J Pediatr Gastroenterol Nutr 1987; 6: 769–774.
Schmidt E: Effects of varying degrees of heat
treatment on milk protein and its nutritional
consequences. Acta Paediatr Scand Suppl
1982; 296: 41–43.
Hassiotou F, Geddes DT, Hartmann PE:
Cells in human milk: state of the science. J
Hum Lact 2013; 29: 171–182.
Chauhan M, Henderson G, McGuire W: Enteral
feeding for very low birth weight infants:
reducing the risk of necrotising enterocolitis.
Arch Dis Child Fetal Neonatal Ed
Narayanan I, et al: A planned prospective
evaluation of the anti-infective property of
varying quantities of expressed human milk.
Acta Paediatr Scand 1982; 71: 441–445.
Arnold LD: The cost-effectiveness of using
banked donor milk in the neonatal intensive
care unit: prevention of necrotizing enterocolitis.
J Hum Lact 2002; 18: 172–177.
Carroll K, Herrmann KR: The cost of using
donor human milk in the NICU to achieve
exclusively human milk feeding through 32
weeks postmenstrual age. Breastfeed Med
2013; 8: 286–290.
Gribble KD: Peer-to-peer milk donors’ and
recipients’ experiences and perceptions of
donor milk banks. J Obstet Gynecol Neonatal
Nurs 2013; 42: 451–461.
Sullivan S, et al: An exclusively human milkbased
diet is associated with a lower rate of
necrotizing enterocolitis than a diet of human
milk and bovine milk-based products.
J Pediatr 2010; 156: 562–567.e1.
Arslanoglu S, et al: Donor human milk in
preterm infant feeding: evidence and recommendations.
J Perinat Med 2010; 38: 347–351.
Moro GE, et al: XII. Human milk in feeding
premature infants: consensus statement. J
Pediatr Gastroenterol Nutr 2015; 61(suppl 1):
About to leave this website
You are about to proceed to an offsite link. Nestlé Nutrition Institute has no control over the content of this site.