HUMAN MILK BANKING PRACTICES

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(Received August 3; accepted for publication September 21, 1970.)

Names and addresses of participants listed at end of article.

ADDRESS FOR CORRESPONDENCE: (W.A.S. ) The Permanente Medical Group, 2200 O’Farrell Street, San Francisco, California 94115.

PEDIATRICS, Vol. 47, No. 2, February 1971

SPECIAL

ARTICLE

HUMAN

MILK

BANKING

PRACTICES

William A. Silverman, M.D., Chairman of Conference

O

N June 13, 1970, an informal meeting

was held in San Francisco sponsored

by the Mothers’ Milk Bank to review

cur-rent methods for collection,

decontamina-tion, and storage of human milk, in the

light of evidence which has accumulated in

the past few years. A number of problems

were identified and several recommenda-tions were made.

Chemical contamination of human milk

was discussed at length and it was

con-cluded that adulteration by ingested drugs is preventable by thorough screening of the donor’s history and the advisement that all

drugs

(

including unusual amounts of

alco-hol, aspirin, and coffee) be avoided by the donor.

Environmental contaminants, especially chlorinated hydrocarbons, are now

ubiqui-tous and it is unrealistic to expect that all

traces of these compounds will disappear

(

or can be removed easily) from human

milk. It appears unlikely that avoidance of

human milk significantly reduces the total

amount of DDT in the body beyond early

infancy, since human milk is not the

pri-mary source of this material; it is

transmit-ted to the fetus across the placenta and is

soon available to the child in other ingested foods

(

especially meat). No physiologic

effects attributable to DDT have been

de-scribed in infants fed human milk

(

e.g.,

amounts are considerably lower than needed

for hepatic microsomal enzyme induction) and “tolerances” have not been established;

nonetheless it is cheering to find that

spo-radic reports of measurements of DDT in

human milk since 1951 give no evidence

that there has been an increase in recent

years

(

Table I

)

It was concluded that it

is not necessary to monitor DDT concentra-tion in the milk of individual donors

(

espe-cially since day to day variations are quite

small

)

; however it was recommended that

measurements be made of pooled samples

at regular intervals to detect long-term

trends. The need for better human data was

stressed, and a specific project

(

paired

mea-surements of DDT in fat obtained at the

time of cesarean section, and in milk

)

was advised.

Other environmental contaminants

(

es-pecially lead, arsenic, and

organophos-phates

)

present no particular problem

be-cause they are not transferred to milk in

any appreciable quantities. Regular

sur-veillance of radioactive contaminants

(

Strontium-90, Iodine-131, and

Cesium-137) in cow’s milkG indicates a relatively

low level of radionuclides in the

environ-ment since the ban on atomic weapons

test-ing in the atmosphere.

The subject of breast milk associated

jaundice was reviewed. It was noted that

approximately 1% of breast fed infants

de-velop prolonged, unconjugated

hyperbili-rubinemia as a result of ingestion of preg-nane-3

(

alpha

)

; 20

(

beta

)

-diol in the milk. Intake of the steroid begins during the first

week of life with the onset of mature milk

secretion but severe jaundice is usually not noted until the second week of life and may persist through the third to tenth weeks of life if nursing is continued. Hyperbiliru-binemia occurs in these infants as a result

of inhibition of the hepatic microsomal

en-zyme-glucuronyl transferase. In the first

few days after birth, breast fed infants

ex-hibit slightly higher plasma levels of biliru-bin than do artificially fed infants, but the

cause for this minor early discrepancy is

unknown. Except for the inhibitory steroid isolated from milk of mothers with infants

having the breast feeding jaundice

syn-drome, no other unusual steriods have been

(2)

chemi-TABLE I

AVERAGE C0NcENTIIATI0N OF TOTAL I)DT IN hUMAN MILK AND MILK FAT

SPECIAL ARTICLE 457

cal or bio-assay examination of donor milk

for presence of substances which could

cause jaundice in neonates through

inhi-bition of glucuronyl transferase is impracti-cal at the present time. However, in a milk bank operation this relatively unusual

prob-lem should not be difficult to manage. A

history of severe or prolonged jaundice in

the donor’s nursing infant may be taken as

a biological screening test, and dilution by

pooling of milks in the bank is a practical way to reduce the likelihood that an infant will receive enough of the inhibitor to pro-duce icterus. Heat sterilization and boiling will not destroy or inactivate the inhibitory steroid.

The advantages of pooling donor milks

were considered to be real

(

especially as

noted, dilution of undesirable compounds,

and insuring uniformity of composition) ; as a result, relatively large pooi sizes (milk from 10 to 20 donors, if possible) were

ad-vised. However, this recommendation

pre-cludes the use of raw bank milk since the

risk of bacterial contamination, even with

careful surveillance of the donors, was

thought to be too great. At present, thermal

treatment7

(

e.g., classic pasteurization, flash sterilization, or terminal sterilization

)

is the

only safe method which can be

recom-mended for pooled human milk.

Unfortu-nately even moderate heat denatures some

immune substances in human milk

(

espe-cially immunoglobulin A) which are

needed for the treatment of some infants

with intractable diarrhea and may be

important in the protection of premature infants against infection. A search for alter-native

(

nonthermal

)

techniques for

decon-taminating and preserving human milk was

strongly advised. At present when raw

hu-man milk is needed for neonates and older

infants, an individual

(

“wet nurse”

)

proce-. .

Invethgalzon lIilkDDTi nppm .ililk fat

Laug, et at. (1951)’ .13 6.5

West(1964)2 .10 5.0

Egan, et at. (England, 1965) .13 6.4

Quinhy, 13!a!. (1965) .1t 6. 0

Curley. el a!. (1969) .07 3. 5

dune was counselled. A current registry of

raw milk donors should be kept by the milk

bank.

The storage of human milk was discussed

and no major problems were identified.

Plastic containers, if used, should be care-fully chosen

(

preferably of food grade

ma-terials

)

to avoid the problem of leaching of plasticizers. Frozen milk can be stored for

extended periods with no appreciable

change in composition. When the milk is

thawed and poured into nursing bottles at

room temperature, it should be used

promptly (within 1 hour) to avoid the risk

of bacterial proliferation. Even if refniger-ated it must be used within 4 hours or

dis-carded. After thawing, milk should not be

refrozen for future use.

Contingency samples

(

a few milliliters of milk from each donor

)

should be frozen be-fore sterilization and filed in the milk bank

“library” for investigational purposes which

may arise.

The subject of human colostrum was not

discussed at any length. There was general

agreement that there is need for more

in-formation to guide practices in the banking of this fluid.

CONFERENCES

WILLIAM A. SILVERMAN, M.D., Chairman Chief, Peninatology Section Kaiser Foundation Hospital

Adjunct Professor of Pediatrics University of California

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LAURENCE NI. GARTNEB, \l.D. Director, Newborn Service Associate Professor of Pediatrics Albert Einstein College of Medicine

New York, New York

MOSES GROSSMAN, M.D. Director, Pediatrics

San Francisco General Hospital Professor of Pediatrics

University of California San Francisco

BRUCE JOHNSON, PH.D. Senior Research Scientist

Product Development Department

Ross Laboratories

Columbus, Ohio

STUART A. PEOPLES, M.D. Professor of Pharmacology

School of Veterinary Medicine

Department of Physiological Sciences

University of California, Davis

PHILIP SUNSITINE, M.D. Director, Newborn Service

Stanford University Medical Center

Associate Professor of Pediatrics Stanford University Medical School

CONSULTANTS

M. N. ABEYTA Senior Dairy and Milk Inspector

Bureau of Dairy and Milk Inspection

San Francisco Department of Public Health

(

Mns.

)

S. M. BESK, R.N. Mothers’ Milk Bank

San Francisco, California

(

MRS.

)

HELEN CARMICHAEL Nursing Mothers Counsel

Palo Alto, California

EDNA M. Courrs, R.N. Children’s Hospital

MRS. WILLIAM DIEDJUCH Mothers’ Milk Bank

Mns. \V. C. FELL President

Mothers’ Milk Bank San Francisco, California

T. HENRY Homo Toxicology Chemistry Laboratory

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SPECIAL ARTICLE 459

(

MRS.

)

BErrY LEONARDS, R.N.

GERALD MERENSTEIN, M.D.

MRS. MILTON SAPER

(

MRS.

)

Rum H. SILVERMAN, R.N.

(

MRS.

)

MARY LOU RAMSEY

MARK YANOVER, M.D.

(

MRS.

)

ROBERTA UEBBING

REFERENCES

1. Laug, E. P., Kunze, F. M., and Prickett, C. S.: Occurrence of DDT in human fat and milk. Arch. Indust. Hyg., 3:245, 1951.

2. Vest, I. : Pesticides as contaminants. Arch. En-viron. Health, 9:626, 1965.

3. Egan, H., Goulding, R., Roburn, J., and Tatton, J. O’G. : Organochlorine pesticide residues in

human fat and human milk. Bnit. Med. J. 2: 66, 1965.

4. Quinby, C. E., Armstrong, J. F., and Durham,

Fellow in Peninatology

Kaiser Foundation Hospital and

Children’s Hospital San Francisco, California

Mothers’ Milk Bank

Nursing Mothers Counsel Palo Alto, California

Permanente Medical Group

Kaiser Foundation Hospital

Nursing Mothers Counsel

Palo Alto, California

\v.

F. : DDT in human milk. Nature, 207:726, 1965.

5. Curley, A., and Kimbrough, R.: Chlorinated hy-drocarbon insectides in plasma and milk of

pregnant and lactating women. Arch. Envi-ron. Health, 18:156, 1969.

6. Bureau of Radiological Health: Milk surveil-lance. Radiol. Health Data Rep., 1 1 : 187, 1970.

7. Committee on Nutrition, American Academy of

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1971;47;456

Pediatrics

William A. Silverman