The Collection and Storage of Human Milk and Human
Milk Banking
Breast milk expression has become a very common practice. Although it is associated with maternal employment, it is also associated with the desire to make it possible for someone else to feed the infant.
Pumping to donate the milk has been an uncommon reason, as has been pumping for a hospitalized infant.
The prevalence of breast milk expression was deter- mined by reviewing the data from the 2005 to 2007 Infant Feeding Practices Study II by the Center for Food Safety and Applied Nutrition, of the Food and Drug Administration (FDA), and the Centers for Disease Control and Prevention (CDC).37 Of mothers whose infants were younger than 4ẵ months, 85% had expressed milk at some time since birth, 43% having done so occasionally and 25% on a regular schedule. The number was higher among first-time mothers and slowly declined as the infant became older (Figures 21-1and21-2).
The human milk bank has entered another era.
The interest in providing human milk for infants with special needs, especially premature infants, has increased, but the concerns regarding donor milk have also escalated. Regulatory bodies have decreed that donor milk must be pasteurized. Milk banks have recognized the need for donors to be carefully screened and women at high risk for cer- tain infections eliminated from the donor pool.
When there are risks associated with using even a mother’s own milk for a given baby, the risk/
benefit ratio is determined. Because of the effects of heating, cooling, freezing, and storing milk, some of the most valued and precious qualities
are diminished or destroyed; feeding the milk fresh or at least fresh frozen and not heated preserves most of the constituents. The value of the milk pro- duced by women who deliver prematurely has been discussed inChapter 15.
Historical Perspective
When “wet nursing” was the immediate alternative feeding to replace a mother’s own milk, and no safe ways were available to store milk of any species, no human milk banks existed.7 As pasteurization became available and formulas based on milk from other species increased in popularity, the pool of human milk diminished. “Wet nurses” were increas- ingly difficult to locate, and often were not safe sources because of wet-nurse lifestyle, risk for infec- tions, and poor nutrition. It had already been clearly demonstrated in the early twentieth century that infants who did not receive their mother’s milk had six times the risk for dying in the first year of life (seeChapter 1).
The impetus behind milk banks at the turn of the twentieth century was actually the medical profes- sion’s desire to remove the control of infant feeding from wet nurses and separate the product (human milk) from the producer. Pediatricians, anxious to improve the prognosis for infants deprived of their own mother’s milk for medical and social reasons, developed a means of storing human milk for gen- eral use for sick infants. The first milk bank was 712
opened in Vienna in 1900. The first one in the United States was established 10 years later at the Massachusetts Infant Asylum, where wet nurses had been the only sources of human milk.29In 1919 the first human milk bank was founded in Germany in Magdeburg by Dr. Marie-Elise Kayser. In 1934, she wrote guidelines that were used throughout Europe for the creation and operation of milk banks.67
Early attempts at providing donor milk depended on casual screening of donors for tuberculosis, syphilis, and various acute contagious diseases.47
There was little research investigating human milk, but the dairy industry was rigorous in its attempt to store and market bovine and other mammalian milks. This technology was applied on a small scale, but other human milk banks appeared after Denny and Talbot created the one in Boston. The Ameri- can Academy of Pediatrics (AAP) established its first formal guidelines for human milk banks in 1943.10,11Similar guidelines were provided in other countries. After World War II, milk banks were mandated on both sides of the Berlin Wall. In 1959 the Federal Republic of Germany (West Ger- many) had 24 milk banks, and the German Demo- cratic Republic had 62.66 The numbers gradually decreased.
As technology advanced in newborn care and in infant nutrition, science replaced nature. The inter- est in human milk faded, and with it the call for banked human milk, in the 1960s and into the 1970s. Experience in Rochester with short-gut syn- drome and malabsorption syndromes, however, resulted in the development of a registry of lactat- ing women, who donated fresh milk when needed.
A milk bank was developed with donors providing frozen milk on a regular basis. By 1975, five large commercial milk banks were operating in Britain.
Milk banks also sprang up across the United States.
The system thrived with the establishment in 1985 of the Human Milk Banking Association of North America (HMBANA). The association not only facilitated communications among banks, but also began to investigate processes, develop uniform policies, and most importantly, provide profes- sional and public education.76
The threat of human immunodeficiency virus (HIV) and hepatitis, the return of tuberculosis, 60
50 40 30 10 20 0 70
Electric pump
Manual pump
Combination pumpa
Battery pump
By hand (no pump)
Percentage
1.5-4.5 mo (n = 1302)
>4.5-6.5 mo (n = 843)
>6.5-9.5 mo (n = 529)
Method
Prevalence of breast milk expression
Figure 21-1.Percentage of breastfeeding mothers who had successfully expressed milk, according to method of milk expres- sion and infant age group. The 1.5- to 4.5-month sample is based on breastfeeding mothers who responded about methods used to successfully express milk since their infant was born; the>4.5- to 6.5-month sample is based on mothers who responded in the previous 3 months; and the>6.5- to 9.5-month sample is based on mothers reporting about methods used in the previous 2 months. Samples are smaller than the total of those who had successfully expressed milk during a given period (1315, 845, and 653, respectively, for the successive age groups) as a result of question nonresponse. Respondents could mark all answers that applied; therefore percentages in each age group do not sum to 100%.aCombination pumps were defined as both electric and battery operated.
60 50 40 30 10 20 0 70 80 90 100
1.5-4.5 (n = 1493)
>4.5-6.5 (n = 1090)
>6.5-8.5 (n = 891)
Percent
On a regular schedule Occasionally None
Age group (mo)
Figure 21-2. Breastfeeding mothers’ prevalence of breast milk expression in the previous 2 weeks, according to infant age-group.
and drug abuse have cast a long shadow on milk banks in the United States. This resulted in the clo- sure of all but seven milk banks in North America and five in the United States in the nineties (see Appendix H). In Europe, milk banking has been key in the nourishment of premature and other high-risk infants. The Sorrento Maternity Hospital has supplied 50,000 L of milk from 10,000 donors in 40 years and provided 700 L a year both locally and across Britain in the nineties.3 In 1994 the remaining 18 milk banks in unified Germany sup- plied about 15,000 L.
Many developing countries, especially in Cen- tral and South America, are establishing milk banks as part of national efforts to promote breastfeed- ing.62Studies done in nurseries in Guatemala have shown a marked decrease in mortality and morbid- ity rates by providing every infant with human milk, especially colostrum.12The United Nations Children’s Fund (UNICEF) has encouraged and supported such efforts.82
The First International Congress on Human Milk Banking: A Vision of the Future was held in Brazil in 2000, sponsored by the Brazilian Associa- tion of Milk Banks. There are 154 milk banks in Bra- zil. Representatives from South America, France, United Kingdom, North America, and the Carib- bean attended. All of the milk banks processed the milk. Some screened the serum of donors, but not all. None paid donors but some did provide pumps.75Regulations vary by locale. A resurgence of milk banks in the United States has occurred in the last 10 years, stimulated in part by the recogni- tion of the value of human milk for premature and especially very-low-birth-weight infants by neona- tologists. Another stimulus was the establishment of a for-profit milk bank in California, approved and licensed by the State of California. This milk bank, supported by venture capitalists, studied the safest ways to process milk. The milk bank was able to measure the caloric value of the milk and provide milk of 20, 22, 24, and 28 cal/oz. Its most important contribution has been the develop- ment of a supplement consisting only of human milk to be used to enhance the protein, calcium, and caloric content of a feeding of mother’s milk for a premature or other compromised infant who requires extra calories, protein, and minerals.
Storing Human Milk
It is often necessary to store milk for infants, espe- cially in the hospital. The storage of human milk involves two types of milk: mother’s milk and donor milk. The distinction becomes important in how the milk is stored and prepared for an infant. It is also important because many states have developed
codes for donor milk but fortunately have not reg- ulated mother’s milk as yet. Certain guidelines are appropriate for each milk. Indications for use of such milk were alluded to in other chapters but are briefly summarized here.
MOTHER’S MILK FOR A HEALTHY INFANT
The conditions under which a mother collects and stores milk while at work are not always ideal. At home, at work, or at school, milk should be col- lected with clean equipment, stored in sterile con- tainers (dishwasher cleaned and dishwasher dried suffices), and handled with just-washed hands.
The limits of temperature and time are an important consideration in the storage of milk.
To assess microbial growth and stability of milk protein and lipid at varying temperatures and for varying lengths of time, Hamosh et al.30collected samples from 16 healthy women with healthy babies who were exclusively breastfed. Sampling was done early in lactation (1 month postpartum) and late in lactation (5 to 6 months postpartum).
The milk pH decreased from 7.020.20 to 5.160.26 after 24 hours of storage at 38°C (100°F), and significant differences in pH occurred at all temperatures at 24 hours or longer. Proteoly- sis was minimal at 15°C (59°F) and 25°C (77°F), but became apparent at 38°C (100°F) at 24 hours.
Lipolysis was marked in the first 24 hours at all tem- peratures compared with freshly expressed milk.
Bacterial growth or normal flora was minimal at 15°C at 24 hours, low at 25°C at 8 hours, and higher at 38°C by 4 hours.
The authors concluded that storage of human milk is safe at 15°C for 24 hours and 25°C (room temperature) for 4 hours and should not be stored at 38°C. Proteins appear to maintain their structure and function in short-term storage. The marked lipolysis appears to slow bacterial growth at the same time.30
PASTEURIZING BREAST MILK AT HOME Many women face the dilemma of discarding milk pumped when they had aCandidainfection of the breast before it was diagnosed. Freezing does not destroy Candida. It has been suggested that milk could be “pasteurized” at home, for use at home by the mother’s own infant. Below are the steps for home pasteurization for one’s own infant, not a milk bank:
Pour all milk into a large saucepan, and place over medium heat on the stove.
Using a candy thermometer, gradually bring the milk to a temperature of 145°F (62.5°C).
Watch closely, and stir often, keeping milk at this temperature for 30 minutes.
Milk can then be poured into appropriate storage containers.
Label each container with the baby’s name and the date and time of pasteurization.
Freeze the pasteurized milk in dishwasher-clean containers until ready for use.
Do not boil the milk (boiling occurs at 212°F or 100°C).
If performed correctly, this process will decrease nutritional and immunologic components by about 30%, but will destroy all microorganisms.
See Protocol 8 in Appendix P for more informa- tion. This milk should not be shared, but used only for the mother’s baby.
MOTHER’S MILK FOR A SICK INFANT The following situations are common scenarios for the use of mother’s own milk.
1. A mother plans to breastfeed the infant ulti- mately but needs to provide pumped milk until the infant can be put to the breast.
2. An infant requires the special nutritional benefits of human milk (as with those infants who are recovering from intestinal surgery), but cannot nurse at the breast.
3. An infant weighs 1500 g or less and has diffi- culty digesting and absorbing other milks and is usually fed by nasogastric tube.
MILK SHARING
Milk sharing has become a popular source of human milk, and the various methods have generated much discussion in various media. Serious analysis of the activity has shown that it is not safe. A care- fully executed study of milk samples purchased on the Internet showed high contamination with bac- teria and, in some cases, pathogenic bacteria. The authors also reported poor collection, storage, and shipping practices. This study did not measure toxins, pharmaceuticals, or medications, which are also a risk in shared milk for the sick or premature infants. Caloric content and protein levels were not measured. Clearly, Internet sharing or selling milk by unscreened donors is not recommended. Small community-based nonprofit milk sharing systems where the donors are screened provide safety. They do not guarantee the caloric content, and it is known that the caloric content can be as low as 15 cal/oz.
Neonatal intensive care units (NICUs) who need milk for high-risk infants should only accept milk from certified sources.
DONOR MILK FROM A MILK BANK
The following scenarios are common reasons for obtaining donor milk from a bank.
1. An infant is at risk for infection or necrotizing enterocolitis. Fresh colostrum is held to be espe- cially protective and may be collected from low- risk, carefully screened mothers, who are not breastfeeding their own infants.
2. An infant has a gastrointestinal anomaly or other reasons for intestinal tract surgery, especially short-gut syndrome.
3. A physician thinks an infant would benefit from the nourishment in human milk because of pre- maturity, especially if the infant weighs less than 1500 g.
4. A mother is temporarily unable to nourish her own breastfed infant completely. It may be that the mother’s supply is inadequate when she first puts the infant to the breast after weeks of pump- ing, or when the mother has been ill or hospital- ized. Usually these infants are already at home.
5. Donor milk is an excellent transition from paren- teral nutrition when mother’s milk is not avail- able. It allows earlier weaning from parenteral solution—earlier than when formula is known to be tolerated.
6. Metabolic disorders, especially amino acid dis- orders, respond well because of the physiologic profile of human milk (decreased casein, tyro- sine, and phenylalanine). In addition, human milk is protective against infection, which may be a serious complication of these disorders.
7. An older infant or child has unique feeding dif- ficulties, usually characterized by an inability to tolerate any oral nourishment except human milk (e.g., a child dying of HIV infection).
STRUCTURE OF A MILK BANK
Most informal and casual milk banks operating in conjunction with a NICU have disappeared.61 NICUs may provide a deep freeze for storage of a mother’s own milk for use by her infant. They store it for feeding of the infant and do not process it at all except to culture random samples for con- tamination. Most do not permit “donating” milk to other infants except by private arrangements between the two mothers with a physician’s approval. No feeding is given to an infant in the hospital without a physician’s order. Smaller public milk banks have phased out since state legislation or local medical practice standards have mandated strict surveillance of samples and pasteurization.
A few large, well-established banks operate in the United States and around the world (Figure 21-3). A network of these milk banks meets and shares information through the HMBANA in
North America.2,76 Copies of the association’s guidelines for milk storage are available for a fee.
HMBANA works closely with the FDA concerning FDA regulations for human tissues and fluids.
Appendix Hprovides the guidelines (Figure 21-4).
The Mother’s Milk Bank of the Institute for Med- ical Research in San Jose, California, was established in 1974. It has a full-time coordinator and a medical director, provides milk for hundreds of infants, and contributes to the fund of knowledge on human milk. Because the milk is provided to patients only by physician’s prescription, it is reimbursable by health insurance carriers of California. Mother’s Milk Bank has developed procedures and policies regarding milk collection, storage, and processing.
This was first described in detail by Asquith et al.2 and documented with an extensive bibliography.
The State of New York passed an amendment to the public health law in 1980, in which it was declared policy that any and all infants requiring
human breast milk be assured access to sufficient quantities of wholesome human breast milk, donated by concerned lactating mothers on a continued and systematic basis. New York State has regulations, which have the force of law, governing human milk banks. They address construction, medical direction, donor qualifications, milk collection and storage, maintenance of records, and milk distribution. They are available on the Internet in Part 52, Subpart 52-9, of Title 10 (Health) of the New York Code of Rules and Regulations, which can be accessed from the New York State Department of Health’s Public web- site at http://www.health.ny.gov/regulations/nycrr/
title_10(accessed 30 April 2015).
Neonatologists caution that the cavalier feeding of unsterile unsupplemented breast milk to premature infants may produce iatrogenic problems. Mothers who pump and save milk for their own infants should follow the instructions/guidelines for storing mother’s own milk (seeAppendix J, Protocol #8).
Los Angeles
San Diego
Phoenix
Monterrey San Antonio
Houston Dallas San
Francisco
Vancouver Calgary Edmonton
AB
SK
MB
CANADA
United States
MEXICO
ON
QC
ME NH VT MA RI CT
NJ DE MD District of Columbia NY
PA
WV OH MI
IN KY TN
GA AL MS
LA FL AR MO IA
IL WI ND MN
SD
NE
KS
OK
TX NM
CO WY MT
ID
UT
AZ NV
CA OR
WA
VA
NC SC BC
Winnipeg
Toronto
Chicago
Montreal
Figure 21-3. HMBANA milk bank locations in the United States and Canada. White markers represent established milk banks;
gray markers represent banks in development. (Data fromwww.hmbana.org/locations(Accessed 26.05.15).)
QUALIFICATIONS OF DONORS
A mother who is willing to donate milk should be healthy and fulfill the following qualifications (Box 21-1):
1. Normal pregnancy and delivery
2. Serologically negative for syphilis, hepatitis B surface antigen, cytomegalovirus (CMV), and HIV
3. No infection, acute or chronic (i.e., not at high risk)
4. Not taking medications, smoking, or using excessive alcohol
5. Capable of carrying out sterile technique 6. If donating for other infants, own child is
healthy and without jaundice
When a directive from the Department of Health and Social Security in Great Britain man- dated HIV testing for donors to milk banks, it was observed that the list of 19 established milk banks dwindled to six.3 The Sorrento Maternity Hospital, however, in accordance with the direc- tive of the Department of Health and Social Secu- rity, screened all donors for HIV antibodies. Only four mothers of 470 potential donors have refused to be tested, contrary to fears that the ruling would discourage donating.3
The donor should not be taking medications regularly, including certain oral contraceptives and any nonprescription medications, such as Milk from donors
expressed daily
Home freezer or refrigerator
Transport to hospital Mother’s own
milk
Expressed
Hospital refrigerator (MFBM)
or freezer, cultured
Thawed if necessary (MFBM)
Mother’s OWN baby without further treatment Home refrigerator
or freezer
Excess
Milk bank freezer
Thawed, pooled
Store in ICN freezer or milk
bank freezer Pasteurized (62.5°F for 30 min) Mother
brings in
Processed breast milk (PBM)
Baby Cultured
Figure 21-4.Flow chart of process for the mother at home pumping for her hospitalized infant(left). The right column outlines the steps a donor takes when collecting milk for the bank. The mother described on theleftcan become a donor if she has an abundance of milk and is screened to be a donor.MFBM,Mother’s frozen breast milk.
BOX 21-1. Donor Screening Procedures 1. Donors answer questions on a verbal health
history screening form. Primary health care providers for the prospective donor and her infant are asked for verification of health.
2. Donors are tested serologically for:
a. HIV-1 and HIV-2 b. HTLV-I and HTLV-II c. Hepatitis B
d. Hepatitis C e. Syphilis
3. Repeat donors are treated as new donors with each pregnancy.
4. Milk banks will cover the cost of the serologic screening if the tests are done by the milk bank.
Reasons for excluding a donor
• Receipt of a blood transfusion or blood products within last 12 months
• Receipt of an organ or tissue transplant within last 12 months
• Regular use of more than 2 oz of hard liquor or its equivalent in a 24-hour period
• Regular use of over-the-counter medications or systemic prescriptions (replacement hormones and some birth control hormones acceptable)
• Use of megadose vitamins or pharmacologically active herbal preparations
• Total vegetarians (vegans) who do not supplement their diet with vitamins
• Use of illegal drugs
• Use of tobacco products
• Silicone breast implants
• History of hepatitis, systemic disorders of any kind, or chronic infections (e.g., HIV, HTLV, TB)