Human Milk Banking: A Review
Courtesy - Dr Carolyn
Nash and Dr Lisa Amir for the Maternal and Child
A human milk bank is a service established for
collecting, screening, processing, storing and
distributing donated human milk.
Donation of breast milk from one woman to an
unrelated infant has a long history. Before
this century, the infant would have been directly
breastfed by the woman who was referred to as
a "wet nurse". Rules governing wet
nursing have been around since 1800 BC. Wet-nursing
itself has had periods throughout history when
it has fallen from favor. For example, in the
15th century, wet nursing became very unpopular
due to the spread of syphilis.
Human milk banking has had similar peaks and
troughs. In the early half of this century,
milk banking saw resurgence in popularity, but
around the 1970s, this began to change. The
first reason for this loss of interest in human
milk was the heavy promotion of infant formula,
including formulas specially designed for preterm
infants. Later, a fear of transmission of viruses,
including HIV, in body fluids led to an anxiety
about donation of body fluids, including breastmilk.
WHO and UNICEF, made a joint statement in 1980:
"Where it is not possible for the biological
mother to breast feed, the first alternative,
if available, should be the use of human milk
from other sources. Human milk banks should
be made available in
Banked human milk
Banked human milk is regarded as "the next
best" after the biological mother's breast
milk. It is used for the treatment of many conditions
(mainly in Neonatal Intensive Care Units: NICUs):
prematurity, malabsorption, short-gut syndrome,
intractable diarrhea, nephrotic syndrome, some
congenital anomalies, formula intolerance, failure
to thrive, immune deficiencies (IgA).
Studies have found that breast milk has a protective
effect against necrotising enterocolitis (NEC).
Lucas and Cole found that NEC was 6-10 times
more likely to develop in exclusively formula
fed infants than in those fed only breast milk,
and that NEC was 3 times more likely when formula-only
fed infants were compared to those receiving
both breast milk and formula. Other studies
have demonstrated that formula fed infants had
lower IQ scores than infants fed breast milk.
Milk banks vary in their use of banked milk.
In some cases, milk is provided for adopted
babies or older children with severe food allergies.
In 1988, 72% of the milk dispensed from all
the milk banks in the USA was prescribed for
infants in neonatal intensive care units, 23%
went to babies at home, and 2% was used for
One of the major issues milk banking faces is
the possibility of transmission of an infectious
disease via the milk. Parents may fear accepting
donated milk for this reason, while doctors
may feel that the benefits of donated milk are
outweighed by the possible legal implications.
Consequently, screening is extremely important.
A system of "triple protection" is
Review of donor's health history
Serum screening and
Heat treatment of all donor breast milk.
The Human Milk Banking Association of North
America (HMBANA) has exhaustive "Guidelines
for the Establishment and Operation of a Human
Milk Bank". There are
similar guidelines for Britain. Both these countries
recommend serological testing every 2 to 6 months
of the donor for HIV 1 and 2, HTLV 1 and 2,
hepatitis B and C and syphilis.
part of screening is a consent form for the woman
and her doctor to ensure that neither the donor
mother nor her infant will suffer if the mother
This varies from milk bank to milk bank. For
some centers, hospital patients are the major
source of donations, while others will ship
milk from interstate from a donor's home. Donors
are educated regarding the most hygienic way
to express milk. Hand expression is the best
method for collection, however some centers
will allow certain types of hand pumps to be
used. Drip milk (milk that drips from the unused
breast during feeding or expressing from the
other breast) has a lower caloric content and
is more susceptible to contamination, but is
acceptable to some centers.
The type of container used for collection also
varies according to what is most readily available.
Polythene bags are associated with a decrease
in the IgA content of milk, while glass is linked
to a loss of leucocytes. The current recommendation
is that glass is best, but world wide many different
types of materials are used. In India steel
utensils / containers are used.
Controls / Pasteurization
Most milk banks do bacterial counts on each
donor's milk before pasteurization, as pasteurization
may be ineffective if the milk is heavily contaminated
with microorganisms. There are no set levels
for colony count levels, but this is an example
one center uses:
< 103 colony-
forming units: milk is used
> 105 colony -forming units: milk
is not used
103 - 105 - forming units: milk is only used
if organisms are skin commensals.
Unless the milk being stored is for a mother's
own infant, banked milk is then pooled; a bacterial
check is done again here to ensure the pooling
process does not lead to contamination. Pooling
is usually from 4 to 6 donors and is thought
to be beneficial because it averages out the
immunological and nutrient content of the milk.
The numbers are kept low so that any contamination
can theoretically be traced back to its source.
In Germany, however, pooling is not used because
of the concern regarding contamination.
Most milk banks pasteurize their milk. The old
protocol was called "Holder Pasteurization"
which meant that milk was heated at 62.5 degrees
Celsius for 30 mins, and some centers still
use this. New guidelines now recommend 56 degrees
Celsius because at this temperature most bacteria
and viruses are adequately dealt with, while
retaining many of the immunological and nutrition
properties of breast milk.
It appears that pasteurized breast milk is as
good as raw breast milk at preventing NEC. The
milk is again checked for bacterial counts after
heat treatment, but no level of growth is accepted.
Some centers analyze each batch of milk for
its nutritional content and labeled appropriately.
Some centers find it appropriate to try to match
the age of the donor's infant to the age of
the recipient, but this is not necessary if
pooled milk is used.
Viruses and Breast
A review of the literature has found that no
banked milk has ever been linked with the transmission
of disease, nor has any worker become infected
due to the handling of the milk. However, continuing
the process of screening and pasteurization
is essential in order to maintain this record.
It is possible for the human immunodeficiency
virus to be transmitted in breastmilk. However,
pasteurization is known to inactivate HIV 1
and 2. HTLV-1 is associated with T-cell leukemia,
so it is recommended that women who test positive
should not breastfeed; the same recommendations
are made for women with HTLV-2.
Hepatitis B is not thought to be transmitted
via breast milk, although at risk babies are
given hepatitis B immunoglobulin and vaccine
to decrease any potential risk. It appears that
there is also a low risk of transmission of
Hepatitis C via breast milk.
Cytomegalovirus is transmitted via breast milk,
although viral shedding varies; less in Colostrum
compared with later in breastfeeding. As with
HIV, viral shedding peaks during seroconversion,
so breastfeeding is not recommended at this
time, even though transmission usually does
not cause symptomatic disease. Immuno-compromised
or very premature infants should be fed on pasteurized
milk, or milk donated from a seronegative mother.
Rubella is potentially transmittable in breast
milk, but no disease is ever seen. It seems
unlikely that herpes is transmitted through
breastfeeding, unless there are herpetic breast
The American milk bank guidelines give clear recommendations
regarding these practical issues. Fresh-raw milk
must be stored continually at 4 degrees Celsius
for no longer that 72 hours following expression,
whereas fresh-frozen milk can be held at 20 degrees
Celsius for 12 months. Heat-treated (pasteurized)
milk may be stored under the same conditions as
The method of transportation varies from shipping
milk in commercial airlines that donate their
cargo space, to refrigerated vans (as for blood
products) or local volunteers driving their own
In France, however, one center lyophilize its
milk (a previously frozen liquid is dried under
vacuum) increasing its storage duration at room
temperature to eighteen months. This technique
is not used in other counties for a number of
reasons: loss of calcium and phosphorous, cost
and possibly inaccurate reconstitution methods.
Most milk banks are "not-for-profit"
organizations. Some are actually incorporated
into an overall hospital budget, whereas others
are completely independent and almost entirely
run by volunteers, or private donors as in India.
Some centers pay their donors, for example Norway
and France. However, most centers make no payment
as it is thought by not paying the donor that
you will attract the "right type of donors
for the right reasons".
In some cases, the recipients are asked to pay
for the donated breast milk mostly to cover
the costs of the screening tests. No infant
is ever denied donor milk, however, on a financial
basis. In England, the milk banks sell the milk
at 15 pounds per liter to the Health Authority
who then incorporate this into their hospital
Milk banks do not have to cost a lot of money,
as shown in India. No cost-benefit analysis
has yet been done, but the benefit of reducing
the incidence of NEC is substantial
compared to the cost of running a milk bank.
The Australian Red Cross Blood Service, Victoria,
is considering establishing a human milk bank
section within their organization.
The basic infrastructure is already in place
within the Blood Bank. The multidisciplinary
team who already handles the donated blood is
well qualified to handle donated breast milk
appropriately. Guidelines for running the milk
bank will be established and followed.
Three questions remain. Firstly, will there
be enough breastfeeding mothers who will want
to donate their milk? The Nursing Mothers' Association
of Australia feels there would be a positive
response from Australian women.
Secondly, will parents accept donated breast
milk for their baby? Pediatricians in NICUs
will have the opportunity to educate parents
regarding the benefits of breast milk over commercially
available formula. Current information will
allay fears of viral and bacterial transmission.
Thirdly, will doctors prescribe donated breast
milk for their patients? A review of the literature
has demonstrated no reason for them not to.
It is encouraging to see that milk banks have
been running successfully now in many countries:
Germany, France, Poland, India, USA, Canada,
Norway and Britain. It would seem a logical
progression that Australia could also offer
this service to ill newborns.
A review of the literature on human milk banking
is very positive. The guidelines for North American
milk banks (which are followed fairly closely
by most other countries) would appear to deal
with the concern of disease transmission. On
the other hand, presently unknown complications
may develop in the future. Therefore, the possible
risks must be weighed against the proven benefits
of breast milk in each case.
In conclusion, the WHO recommends, "where
a baby is unable to receive the biological mother's
milk, milk of another mother is next best".
In order to ensure a safe supply of breast milk
for all infants, regulated milk banking is the
safest means of doing this.