INTRODUCTION

Breastfeeding is believed to provide substantive advantages to both
the mother and the infant. The mother's choice to breastfeed is most
likely based upon the family's knowledge of breastfeeding and their per-
ception of the environment in which the infant will be fed. Certain bar-
riers at home, work, or school, or in the health care delivery system or
the community can negatively influence both a woman's decision to
breastfeed and her breastfeeding experience. The promotion of
breastfeeding, a national priority, can be achieved through changing
community views.

Knowledge and acceptance of breastfeeding by the general public
are influenced by not only the media but also cultural and ethnic back-
ground, community attitudes, family patterns, and formal education. The
community attitude to be fostered is that breastfeeding is a normal part
of everyday life. A positive attitude toward breastfeeding must be pro-
moted in future parents; public officials and employers must be encour-
aged to remove barriers to breastfeeding; the health care system must
review its policies and procedures to insure that they facilitate
breastfeeding; multi-media approaches to specific target audiences must
be developed; the education of health professionals on the physiology of
lactation and the management of breastfeeding for optimal infant health
must be enhanced.

Excellent models of support in initiation and continuation of
breastfeeding exist. These models need to be shared for application in a
variety of settings. To assess the current status of breastfeeding in the
United States and to develop strategies to facilitate breastfeeding, Dr.
Koop convened the Third Surgeon General's Workshop at the Univer-
sity of Rochester, June 11-12, 1984. The Workshop on Breastfeeding and
Human Lactation brought together from a wide range of disciplines and
settings health professionals who serve different ethnic and cultural
groups throughout the nation. One hundred invited participants included
representatives of professional and lay organizations, local, state and fed-
eral governments, industry, and volunteer groups.

  Speakers at the opening session discussed the physiology and proc-
ess of human lactation, the composition of human milk, trends in
breastfeeding, socio-anthropologic factors, and successful approaches for
promoting breastfeeding. The roles of the lay volunteer and of the media
in the promotion of breastfeeding were highlighted. Participants con-
vened in work groups to consider key issues such as the decision to
breastfeed, socio-cultural influences and determinants of infant feeding
practices, support services for mothers who breastfeed, roles and respon-
sibilities of the health care system in promoting breastfeeding, vocational

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supports and barriers to breastfeeding, educating health professionals and
the public about breastfeeding,  and research needs related to
breastfeeding and human lactation. Excerpts from presentations and rec-
ommendations of the work groups are included in this Report.

Presenting the findings and recommendations of the Workshop to
the Surgeon General, Workshop Chairperson Ruth Lawrence, M.D.,
synthesized the deliberations of the participants in her summary. The
Surgeon General accepted the report, commented on the general topics,
and stated that this Report of the Workshop would be prepared for
widespread dissemination.

2


KEYNOTE ADDRESS

C. Everett Koop, M.D., Sc.D.
Surgeon General and Deputy Assistant Secretary for Health

In 1978 the World Health Organization set for itself a goal of health
for all by the year 2000. Now this is a tall order, and many of the lesser
developed countries-those with limited resources-will have trouble in
meeting that goal. Other countries, with help from some of the more de-
veloped countries in the western world, will succeed in at least improv-
ing health for all in their countries by the year 2ooO only to see those
gains slip as support is subsequently withdrawn.

The United States is a signatory to "health for all" by the year 2000,
but we in this country had previously set ourselves a series of objectives
to be realized not by the year 2000, but by 1990. These are largely con-
tained in a publication called Healrhy People, the Surgeon General's
Report on Health Promotion and Disease Prevention. This volume was
subsequently supplemented by Objectives for the Nation Among the na-
tional objectives for the United States by the year 1990 is the topic of
this Workshop. This objective states: "The proportion of women who
breastfeed their babies at hospital discharge should be increased to 75%,
and the percentage of those still breastfeeding at 6 months of age should
be increased to 35%." In 1978, when this objective was chosen, the pro-
portion was 45% at hospital discharge and 21% at 6 months of age. His-
torically the federal government has not been idle in the promotion of
breastfeeding. During the years 1946-47 Dr. Katherine Bain of the Chil-
dren's Bureau conducted the first nationwide survey on the incidence of
breastfeeding in hospitals in the United States. This report was published
in Pediatrics in September 1948.

A symposium on human lactation was held at George Washington
University in October 1976 and was co-sponsored by the Public Health
Service, the March of Dimes, and George Washington University. The
proceedings of that symposium were widely disseminated in public
health circles. In 1978, an annotated bibliography on breastfeeding, sup-
ported by the Public Health Service, was published by the National
Academy of Sciences. Then in 1983, a nationwide video-teleconference
on improving nutrition of mothers and babies was co-sponsored by the
Department of Health and Human Services and the United States De-
partment of Agriculture. "Breastfeeding and Human Lactation" was one
of two major topics presented during this 3-hour program viewed at 125
sites coast-to-coast. The program presented an update of new research
findings with special emphasis on practical application. Edited videotapes
of the teleconference are now being disseminated. The Public Health

3


Service has not been idle in current activities. Breastfeeding promotion is
one of the thrusts of the Healthy Mothers/Healthy Babies Coalition. A
breastfeeding kit for professionals is now being produced in collaboration
with several professional organizations, voluntary associations, the De-
partment of Health and Human Services, and the United States Depart-
ment of Agriculture. The National Natality Survey of the National
Center for Health Statistics provides an ongoing surveillance and report-
ing mechanism on educational factors associated with breastfeeding.

But let us return for a moment to objectives for the nation. The cur-
rent roles of the federal government in promoting breastfeeding to meet
the already mentioned 1990 national objective include the following:
  o establishing and promulgating policy;
  o offering professional consultation and technical assistance to
    providers;
  o supporting professional training;
  o conducting research;
  o implementing service delivery; and
  o sponsoring public education.
Let me highlight some of these points. In reference to policy on nu-
trition, the guidelines and policies issued by recognized professional or-
ganizations such as the American Academy of Pediatrics, the American
College of Obstetricians and Gynecologists, the American Academy of
Family Physicians, the National Academy of Sciences, and the Associa-
tion of State and Territorial Health Officials are used by the Public
Health Service in formulating policies and recommendations in maternal
and child nutrition.

  Professional consultation and technical assistance on maternal nutri-
tion, lactation, and infant nutrition are made available through guidance
materials and technical references developed in concert with professional
organizations. For example, recommendations on breastfeeding and other
information on infant feeding are addressed in the Pediatric Nutrition
Handbook published by the American Academy of Pediatrics with the
support of the Division of Maternal and Child Health. An example of a
more recently developed technical reference is Guide to Breasfeeding the
Infant with PKU.

Another federal role is the support of professional training.
Breastfeeding is included in the curriculum of graduate training pro-
grams in public health nutrition and in the maternal and child health cur-
riculum for physicians, nurses, social workers, and other health-care pro-
viders. For example, over the last 10 years, 200 public health nutritionists
have received Title V/Maternal and Child Health support, and 107 nutri-
tionists have received National Health Service Corps scholarships for
training leading to a master's degree.

  As in ah of these endeavors, research and study form the basis for
policy and practice. In government, the National Institutes of Health
plays a major role in breastfeeding research efforts. A revival of interest
in the composition of human milk and the special functions of its many
components has been stimulated by the necessity of devising proper nu-
trient therapy for premature, growth-retarded, and immunologically

4


compromised babies. The National Institute of Child Health and Human
Development has stimulated studies of immunologic and nutrient compo-
sition, as well as perhaps undefined components and possible contami-
nants of coiostrum and human milk obtained from mothers delivering
babies at various gestational ages. In addition, in response to the recom-
mendations from workshops held by the Division of Maternal and Child
Health, in both 1975 and 1976, the National Institute of Child Health and
Human Development is supporting applied studies of human milk-bank-
ing in order to develop techniques of collecting, storing, and distributing
human milk and colostrum for use- in clinical situations. Currently tech-
niques are being developed to combat viral contamination without de-
stroying immunologically active cells or denaturing proteins that possess
antimicrobial activities. The eventual isolation of special immunologic
and nutrient components of human milk which could assist in the care of
premature and growth-retarded babies will be the hoped-for outcome of
such research. As a matter of fact, a workshop was held in September
1982 on human-milk banking in order to provide further stimulation for
this expanding research. The report will be available this summer. The
National Institute of Allergy and Infectious Diseases is studying the role
of breastmilk as a defense against enteric infections. The National Insti-
tute of Environmental Health Sciences is conducting a longitudinal study
of 900 children in. North Carolina to see if childhood morbidity is attrib-
utable to DDT and PCBs in breastmilk.
  In response to the controversy over the International Code of Mar-
keting of Breastmilk Substitutes, two task forces were established by the
Assistant Secretary for Health in November 1981. A Public Health Serv-
ice Task Force on the assessment of scientific evidence relating to prob-
lems of infant feeding, both in domestic and international context, was
chaired by the then-Director of the Centers for Disease Control, Dr.
William Foege. These findings will be published as a supplement to Pedi-
atrics in October 1984. I chaired the other task force on domestic activi-
ties, and the findings have been incorporated into a report that I made to
the World Health Assembly last month in Geneva.
  Education, perhaps the most important aspect of all, should not
really be left until the last. Educational materials on nutrition for use in
counseling parents and other caregivers of children in community health
education programs have been developed by the Public Health Service.
Maternal and Child Health funds are frequently used by the states to dis-
seminate educational materials. An example of this is Breastfeeding, a
publication developed in 1979 and aimed at parents-to-be and new par-
ents. Other federal agencies such as the United States Department of
Agriculture, voluntary groups such as La Leche League, and practition-
ers as well as parents had the opportunity to review the material in draft
and make suggestions. Thus, the publication is as practical and useful as


possible. To date, over 60,000 copies of the publication have been
distributed nationwide.

  Now you might wonder why we are having this Surgeon General's
Workshop on Breastfeeding and Human Lactation. Although the number
of breastfed infants has grown in recent years, the increase has not been
as great in the highest risk groups. The number of women who start to
breastfeed has increased, but many of them do not continue breastfeeding
beyond the first few weeks of their infant's life. We know that
breastfeeding gives babies complete nutrition plus immunologic benefits
to launch them on a healthy life. Breastfeeding also provides its particu-
lar benefits at a low cost. We must therefore identify and reduce those
barriers which keep women from initiating or continuing to breastfeed
their infants. And it is now time to consider what needs to be done. You
have already heard a little bit of why we chose the University of Roch-
ester, but let me expand on that. The University of Rochester School of
Medicine and Dentistry was selected because of its active and unique ef-
forts in the support of breastfeeding. Along with the School of Arts and
Sciences and the School of Nursing, the School of Medicine and Den-
tistry has developed a cluster for the interdisciplinary study of the phys-
iologic, psychologic, sociologic, and anthropologic aspects of human lac-
tation. Dr. Ruth Lawrence, Associate Professor of Pediatrics and of Ob-
stetrics and Gynecology, is the workshop chairperson and a nationally
recognized authority on breastfeeding. She is the author of the primary
text on the subject entitled Breastfeeding: A Guide for the Medical Profes-
sion. The University of Rochester has a strong Obstetrics and Gynecol-
ogy Department whose chairman is Dr. Henry Thiede. He is co-chair-
person of this workshop. Dr. Thiede, in his prior position as the Chair-
man of OB/GYN at the University of Mississippi, was instrumental in
the creation of the certified nurse/midwifery training program.

Now, let us turn our attention to what will be going on here for the
next two days. The luncheon speaker today will highlight the role of the
lay volunteer in the mother-to-mother program of the La Leche League.
On Tuesday, Bob Bazell, Health and Science Correspondent for NBC,
will discuss the use of media in promoting breastfeeding. Speakers this
morning will give us an update on the state of the art and the state of
science on the physiology of breastfeeding, the unique values of human
milk, current trends, and cultural factors related to breastfeeding. This
introduction will provide background for the discussions to follow in the ,
work groups. Models of successful approaches will also be presented this
morning, in order that they become part of our knowledge base. This
afternoon and continuing through tomorrow morning, participants will
convene in 8 work groups to consider and make recommendations on
key issues, such as:

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  o the decision to breastfeed;
  o so&cultural influences and determinants of infant feeding
   practices;
  G support services needed for initiation and continuation of
   breastfeeding;
  o roles and responsibilities of the health-care system in promoting
   breastfeeding;
  o overcoming barriers to breastfeeding in the world of work,
  o educating health professionals and the public about
   breastfeeding; and
  o research needs in breastfeeding and human lactation.
My charge to the participants of this Workshop is to report the fol-
lowing: which efforts have been successful, which need better applica-
tion, what else do we need to know, and what of the above will better
promote breastfeeding among high-risk groups in order to realize greater
benefits? Now this charge, as I stated earlier, is a tall order, but I know
that you will do this, I know that you will do it well, and I will be here
tomorrow afternoon to receive your report.
  Thank you very much.


EXCERPTS FROM PRESENTATIONS

HUMAN LACTATION AS A PHYSIOLOGIC
  PROCESS

Ruth A. Lawrence, M.D.

Lactation is the physiologic completion of the reproductive cycle.
The breast, the body, and the psyche are prepared for lactation during
pregnancy. The newborn infant is prepared to suckle at the breast at
birth.

Growth of the mammary gland is a gradual process that starts
during puberty under the influence of the sex steroids. The embryonic
buds which developed initially in the fetus and have been quiescent since
birth are stimulated by estrogen to proliferate and to become multilay-
ered. Buds and papillae are formed. The lobuloalveolar development and
ductal proliferation depend on the intact pituitary gland.

There are three major stages of activity: I) mammogenesis-mam-
mary growth, which begins embryonically and culminates during preg-
nancy, 2) lactogenesis-the initiation of milk secretion, which begins in
pregnancy and increases at delivery, 3) galactopoeisis-maintenance of
established lactation, which begins a few days postpartum and continues
as long as there is stimulus.

The embryonic breast begins its preparation at puberty when the hy-
pophyseal-ovarian-uterine cycle is established. Fifteen to 20 primitive
ducts arborize extensively and form a compound tubuloalveolar gland. A
relatively inactive stage continues through adult life until pregnancy ini-
tiates the proliferative stage. Spectacular ductal growth begins in re-
sponse to luteal and placental hormones. There is true hyperplasia, but in
an orderly fashion, as one alveolus does not overrun another. (Figure I)

The hormones-placental lactogen, prolactin, and chorionic gonado-
tropin-contribute to the acceleration of growth. At this stage one can
observe the complex interaction of the many hormones that function in
the development of both the fetus and the breasts during pregnancy. Es-
trogen stimulates ductular sprouting, and progesterone stimulates lobular
formation. There is a delicate balance of prolactin inhibiting factor in the
hypothalamus and prolactin production in the adenohypophysis as the
presecretory phase progresses in the second trimester to a secretory
phase. In this phase, material resembling colostrum is seen in the alveoli
stimulated by placental lactogen.

A mother delivering a previable infant at 16-weeks gestation will se-
crete colostrum. As early as 24 weeks, lipid droplets can be seen in the

9


     A          8          C          D          E
Figure 1. Female breast from infancy to lactation with corresponding cross section and
duct structure. A, B, and C, Gradual development of well-differentiated ductular and pe-
ripheral lobular-alveolar system. D, Ductular sprouting and intensified peripheral lobular-
alveolar development in pregnancy. Glandular luminal cells begin actively synthesizing
milk fat and proteins near term; only small amounts are released into lumen. E, With post-
partum withdrawal of luteal and placental sex steroids and placental lactogen, prolactin is
able to induce full secretory activity of alveolar cells and release of milk into alveoli and
smaller ducts.

alveolar cells. The composition of the secretion is fairly consistent from
16-17 weeks right up to the time of delivery.

With the delivery of the placenta, the source of hormones is lost
abruptly and the plasma levels begin to fall. Placental lactogen is gone
within hours, progesterone within 2-3 days, estrogen reaches basal levels
within 5-6 days, but prolactin levels depend upon the amount of suck-
ling. In the non-nursing mother, prolactin drops to prepregnant levels in
about 14 days. Observation of nursing mothers with retained placenta in-
dicates that lactation is suppressed until the placental fragments are re-
moved. This supression is similar to the lack of milk secretion seen in
mothers experiencing an intrauterine death. Evidence strongly suggests
that it is loss of the placental progesterone with the decline in plasma
progesterone which triggers galactogenesis, or milk production.

The necessity for adequate levels of prolactin for lactation to begin
in humans has been demonstrated. The exact role of prolactin in ade-

10


quate milk production, however, continues under investigation. In the
first week postpartum, the high levels of prolactin are only slightly aug-
mented by nursing. In the second stage, from 2 weeks to 2 months, base-
line levels of prolactin are 2-3 times normal, and increase to 10-20 times
normal with suckling. The third phase begins at about 3 months and lasts
to weaning. Prolactin levels are almost normal, and no rise is seen with
suckling, even though milk production continues.

  The role of other hormones such as insulin and thyroxine in
mammogenesis, lactogenesis, and galactogenesis is well established, but
the definition of their roles does not have universal agreement. The
breast does not function in isolation, but in synchrony and balance with
the maternal endocrine system.

The process of milk synthesis is complex. There is a marked alter-
ation of the maternal metabolism with a redistribution of the blood
supply and an increased demand for nutrients. The mammary blood
flow, cardiac output, and milk secretion are suckling-dependent. These
changes in turn trigger the hypothalamus to release prolactin to act on
the mammary cells. Milk is iso-osmolar with plasma in all species. Al-
though milks of different species vary tremendously, each is physio-
logic for the growth demands of that species.
The biosynthesis of milk involves a cellular site where the metabolic
processes occur. Milk is secreted by apocrine and merocrine mechanisms.
Protein and fat are synthesized de novo; lactose is synthesized from glu-
cose; ions and water diffuse across the membrane so that primary alveo-
lar milk is diluted to plasma isotonicity by water extracted from extracel-
lular fluid.

While the glands prepare for full lactation, other structures of the
breast prepare as well. The areolae increase in prominence with the de-
velopment and activity of the glands of Morgagni which provide a secre-
tion to lubricate and protect the nipple and areolae during suckling.
Some of the zealous rituals recommended to mothers during pregnancy
(such as scrubbing, buffing, and stretching these tissues) actually interfere
with nature's process.

During pregnancy, the body stores nutrients that are intended for
the manufacturing of milk in the postpartum period. Eight to 10 pounds
of added weight (neither fetus, placenta, uterus, or fluid) are carefully
stored for future nutrient and energy needs. The body stores reflect the
cumulative dietary intake of prepregnancy and pregnancy coupled with
the short-term dietary variation to ensure daily sources of both macro-
and micronutrients. Thus the daily nourishment provided through the
milk is consistent and balanced. Temporary deficiencies of diet are com-
pensated by body stores.

Lactation also influences the return to prepregnant state for the
mother. Getting back "in shape" is facilitated by utilizing the extra
weight of pregnancy for milk production. Thus, breastfeeding women
return to baseline weight more quickly.

The direct effect of the oxytocin released on stimulus of suckling
not only contracts the myoepithelial cells for milk ejection but also con-
tracts the uterus for faster physiologic involution and increased tone.

11


  In most anticipated normal pregnancies, a woman finds that the hor-
monal milieu triggers latent maternal instincts leading to anticipation of
holding the infant closely to the breast and providing continued nourish-
ment. Parenthood potentially provides the opportunity for psychologic
growth from the egocentricity of adolescence to an adult self-concept in
which the mother cares for and nourishes this new being.

  The mind, however, is not controlled by body function alone. Many
societal, community, family, and individual forces influence attitudes and
feelings about breastfeeding. If a woman rejects her own mother as a
model, other life experiences prevail. There are other psychodynamic
issues and social trends that may lead to negative decisions about
breastfeeding.

In the meanwhile, the fetus is simultaneously undergoing develop-
ment. The infant is prepared to suckle shortly after birth. The newborn
already has been making sucking motions in utero. Part of the balance of
the amount of amniotic fluid depends upon the fetus sucking and swal-
lowing fluid in utero. Until birth, the infant has not had to synchronize
this action with breathing, but as Tizzard showed in England some years

Hypothalamus

Figure 2. Diagrammatical outline of ejection reflex arc. When infant suckles breast, he stim-
ulates mechanoreceptors in nipple and areola that send stimulus along nerve pathways to
hypothalamus, which stimulates the posterior pituitary to release oxytocin. It is carried via
bloodstream to breast and uterus. Oxytocin stimulates myoepithelial cells in breast to con-
tract and eject milk from alveolus. Prolactin is responsible for milk production in alveolus.
It is secreted by anterior pituitary gland in response to suckling. Stress such as pain and
anxiety can inhibit let-down reflex. The sight or cry of infant can stimulate it.

Figures by permission of C. K Mosby Cotipany.

12


ago, suckling at the breast is compatible with continuous breathing com-
pared to the suck-swallow-breathe pattern of the infant while bottle feed-
ing. The infant also has a rooting reflex that helps him turn to grasp the
nipple. The normal newborn infant adapts to breastfeeding readily.
When the infant grasps the nipple and areola, the sucking stimulates
the nerve fibers in the nipple and these, in turn, stimulate the afferent
nerve fibers via the spinal cord to the mesencephalon and the
hypothalamus in the maternal brain and trigger the pituitary to release
two hormones-prolactin and oxytocin. (Figure 2) The prolactin stimu-
lates the synthesis and secretion of milk itself. The oxytocin rapidly
causes the ejection of milk from alveoli and smaller ducts into larger lac-
tiferous ducts and sinuses by stimulating the myoepithelial cells to con-
tract. The myoepithelial cells (or basket cells) are wrapped about the
ducts, and when they contract, milk is ejected. Milk ejection involves
both neural and endocrine stimulation and response. A neural afferent
pathway and an endocrine efferent pathway are required, but this stimu-
lus is triggered predominantly by touch and not by pressure of a full
milk gland. This response may be inhibited by pain or stress.
  Breastfeeding is not a reflex; it is a learned process. In our present
culture, many women have never witnessed an infant at the breast. When
a woman is called upon to nurSe her own infant, much of her success
depends on a learning process. Successful lactation depends on proper in-
formation. As increased numbers of women breastfeed, we need more
knowledge to help those who have difficulty in lactating. Another phys-
iologic effect of lactation-important, though it receives little notice-is
the suppression of ovulation and of menses. There is a temporal differ-
ence in the return of menses and ovulation among women who fully lac-
tate, who partially lactate, and who have either discontinued breastfeed-
ing or never began. The nonlactating woman ovulates within 4-6 weeks
of delivery; the lactating woman does not ovulate for 4 months or more.
This effect plays a role in general population statistics.
  Finally, as we look at all the physiologic processes, the interaction
of the breast with the mother's other bodily functions, we see that breast-
feeding is an art-one based on the science of lactation. We need to con-
tinue our explorations, for as Aristotle would have it: "There is a reason
behind all these things in nature."

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THE UNIQUE VALUES OF HUMAN MILK

Cutberto Garza, M.D., Ph.D.

Introduction

  Recommendations of human milk as the ideal nutrient source for
term infants are common. These endorsements and the growing clinical
interest in its use have prompted a remarkable increase in studies of
human milk. The results of such investigations have underscored the dual
roles played by its constituents: 1) the classic role that is associated with
most nutrients, i.e., the provision of enzymatic cofactors or substrates for
energy or structural components and 2) a more complex role that is the
performance of functions complementing the developing abilities of ma-
turing infants. For example, proteins provide amino acids for growth, but
they occur in the form of polypeptides that aid in digestion, host defense,
and other functions. Lipids provide a major source of energy, but some
also have antiviral properties that may impart protection to the develop-
ing infant. In addition, this nutrient class provides fat-soluble vitamins
and essential fatty acids that are important structural membrane compo-
nents, especially in the nervous system. Carbohydrates provide a signifi-
cant portion of the energy in milk and also enhance mineral absorption,
i.e., calcium; modulate the growth of bacteria, i.e., bifidus factor; and
possibly act to prevent the attachment of selected bacteria to
retropharyngeal and other epithelial cells found in respiratory and gas-
trointestinal surfaces exposed to environmental pathogens.

Milk Intake of Breastfed Infants

The unique pattern of constituents in human milk and the feeding
practices inherent to breastfeeding appear to result in distinctive levels of
milk intake between breast- and formula-fed infants. Recent data indicate
that the intake of breastfed infants reaches a plateau at approximately 733
g/day through the first 4 months of lactation. Therefore, on a body
weight basis, the energy intake falls from approximately 110 to 70 kcal/
kg by the fourth month. These intakes are substantially below those of
formula-fed infants and below levels currently recommended for this age
group by the National Research Council.

Despite these differences between recommended amounts and ob-
served intakes, exclusively breastfed infants appear to grow well. Never-
theless, the possibility that human milk may become limiting by the
fourth month for most infants has been suggested. Current measurements
of the intakes of infants whose diets are supplemented ad libitum with
solids, however, do not support this view. Results of these recent studies
indicate that when the diet of the exclusively breastfed infant is comple-
mented with solid foods, intakes remain at approximately 70 k&/kg, and
infants continue to grow well.

14


These findings raise interesting points for discussion. They suggest
that a child's energy intake is dependent upon the mode of feeding. It is
not clear if the differences in intake between formula- and breastfed in-
fants represent a more active "gate-keeping" role by mothers of formula-
fed infants or represent sound physiologic responses to different nutrient
sources.. Formula-fed infants may require "more" food to attain approxi-
mately the same endpoint as their human-milk-fed counterparts. Human
milk is a highly complex mixture with a nutrient balance that may pro-
mote a level of metabolic efficiency unattainable by the formula-fed
infant. Yet, if we compare present estimates of the quantities of energy
required for growth and maintenance by the Cmonth-old infant, it ap
pears that the exclusively breastfed infant would have no energy avail-
able for activity. Are the metabolic economies recruited to achieve the
apparent high level of efftciency in the breastfed infant accomplished by
more conservative uses of energy for growth and maintenance, or are
these efficiencies accomplished by a significant curtailment in activity?
Are the same levels of efftciency possible under hostile environments? If
the energy consumed by bottle-fed infants represents a true excess, are
there any positive or negative short-term or long-term consequences?
These observations pose questions of significance to the general health of
all infants.

Functional Components: An Example-Secretory IgA

The issues raised by the differences between energy and protein in-
takes of formula- and human-milk-fed infants are interrelated with the in
vivo roles of milk components with demonstrated functional potentials.
Of these components, those with protective functions have been exam-
ined most actively. Secretory IgA (SIgA) is the predominant immuno-
globulin in human milk and is thought to represent one of its key protec-
tive agents.

Specific SIgA antibodies are found against a wide array of bacterial
and viral organisms. This protein has the ability to adhere to mucosal
surfaces and prevent the subsequent attachment, and possibly the inva-
sion, of specific infectious agents. Significant data exist indicating that
the appearance of these specific antibodies in milk is a response to envi-
ronmental challenges. Specific antibodies have been observed in the first
few weeks of lactation and are known to persist through 2 years of lacta-
tion. Observations made during weaning suggest that these antibodies
persist through the period of decreased suckling stimulation.

  The presence in human milk of SIgA antibodies which act against
potential pathogens in the maternal environment provides for "environ-
mentally specific" milk. The mechanism by which these antibodies, di-
rected against gastrointestinal and respiratory pathogens, appear in
human milk has been difficult to identify. In contrast to the gastrointesti-
nal and respiratory tracts, where such SIgA is abundant, direct contact
with such antigens is unlikely to occur in breast tissue. Experimental data
suggest that immune  cells  travel from  gastrointestinal   and
respiratory-associated immune tissues to multiple mucosal surfaces, in-

15


eluding breast tissue, and thereby effect the same specific immunity to all
mucosal surfaces. During lactation, the "homing" of these cells to the
breast appears to be activated by hormonal profiles which exist only in
lactating women. The concept of a gastrointestinal-respiratory-mammary
immune circulation provides an explanation of the means by which anti-
gen stimulation at distant sites results in the local production of specific
SIgA antibodies in milk.

This is one example of a protein with a great degree of specificity.
There are other proteins that have more general, potentially protective
functions. It is important to emphasize that carbohydrates and fats also
have functions which may contribute to the high level of metabolic efft-
ciency apparently characteristic of the breastfed infant.

Significance of Functional Components

Although the potential roles of specific antibodies, nonspecific
immunologic factors, and other functional components may be extrapo-
lated from laboratory studies, a definitive demonstration of their signifi-
cance in free-living populations has been much more problematic. For
example, differences in morbidity between bottle- and breastfed infants
often are difftcult to interpret because of confounding environmental and
demographic variables. Factors such as the degree of preventable con-
tamination of artificial formulas, the number of caretakers with whom
the child has contact, the behavioral characteristics of the caretaker-in-
cluding sanitation practices and other mothering skills, the number of po-
tential disease-carrying contacts, etc.- are difficult to control unless ap-
propriate data are collected and sufficiently large numbers of subjects are
recruited. Research designs must account for the "unidirectional" flow of
infants from one feeding category to another. A breastfed infant may
become exclusively bottle-fed for many reasons. An exclusively bottle-
fed infant, however, is unlikely to become exclusively breastfed. Al-
though most studies that compare morbidity among children fed human
milk or synthetic formula have not controlled adequately for all of the
confounding factors, most studies from developed and developing coun-
tries have reported significantly fewer illnesses in breastfed infants. A
few have found no differences, but there are no reports of increased
morbidity among the human-milk-fed groups. Differences in morbidity
between feeding groups have been demonstrated more consistently, how-
ever, in developing countries than in developed countries. Whereas avail-
able data are not conclusive, they generally support the theory that
human milk provides components that complement a developing immune
system in the infant. Although it is not known whether these comple-
mentary components participate in the improved development of active
immunoprotective abilities, they may serve as substitutes until the infant
matures sufficiently to mount an active immune response. Whether or
not the protective effects of human milk components are made real or
potential by environmental conditions, such benefits are available only if
the infant is breastfed.

16


Conclusion

Knowledge of the apparent differences between the ad libitum in-
takes of breast- and formula-fed infants, changes in the composition of
human milk as lactation progresses, and responses of immunologic fac-
tors in human milk which effect environmentally specific protection con-
tribute to the consensus that feeding human milk to infants is beneficial.
The implementation of this consensus requires the identification of bar-
riers that impede successful lactation. The consensus that recommends
human milk also poses a significant opportunity to private and public
health services to aid in the implementation of a practice which pro-
motes health and fosters greater individual responsibility for health.

17


TRENDS IN BREASTFEEDING IN
  THE UNITED STATES

Gilbert A. Martinez, M.B.A.

In 1971 the incidence of breastfeeding declined to its lowest level-
25%. Since then, breastfeeding has increased to 61.9% in 1982 and has
declined marginally to 61.4% in 1983. (Figure 1)

The duration of breastfeeding similarly declined in 1971 to its lowest
level of 9% of women who breastfed 3 months or longer. Since then,
breastfeeding for at least 3 months has increased to 40% of women
giving birth in 1983.

Between 1978 and 1983 breastfeeding increased from 47% to 61%
nationally, with substantial variation among socio-demographic groups.
The highest incidence of breastfeeding occurs among well-educated, rela-
tively affluent, somewhat older women living in the Western part of the
country. Conversely, the lowest proportion of women breastfeeding is
among mothers under 20 years of age, grade-school educated, lower
income, black, and living in the East South Central part of the country-
Kentucky, Tennessee, Alabama, and Mississippi. (Figure 2; Table 1)

The proportion of women breastfeeding their infants at 5 and 6
months of age increased from about 20% in 1978 to 27% in 1983. The

96
70

60

50

40

30

FIGURE l- Incidence of Breastfeeding U&A.
% of Infants Breastfed by Year 1970.1983

- In-Hospital (Ross)     /-

r

L- Government

01      I      I      I      I      I      I      I      I      t      I
70 71 72 73 74   '75 76-77 '78-79 '80-81  '82 '83

Savs: Ram bbombxks Naticd Mothas Survey
   Nati!mal Survey Family Growth, NCHS

18


FIGURE 2. MS3 Incidence of Bread-g by US. Census Regions

@@ h than 58.4    m 58.4 - 61.4
ffjJ&Q 61.4 - 75.0      m Above 75.0

Source: Ross Laboratoti National Mothers Survey

same differences by socioeconomic groups previously mentioned prevail
at 5 and 6 months of age.

The most rapid percentage increases in the incidence of breastfeed-
ing between 1978 and 1983 occurred among women with the least educa-
tion, employed full-time, multiparous, and in the West South Central
area-Arkansas, Louisiana, Oklahoma, and Texas. The least rapid per-
centage growth occurred among mothers under 20 years of age, the
well-educated, the unemployed, and those with lower incomes.
The proportion of black women who breastfed their infants in 1978
is unavailable. Hendershot reported 17% of black women breastfed their
infants in 1975. For the 2-year period of 1978-1979, 24% of black infants
were breastfed. In 1983 that figure had increased to 32%. (Figure 3)
The proportion of black women who breastfed their infants in 1983
for 3 months or more was 20%, and was less than half of the 42% of
white women who breastfed for 3 months or more.
Among black women, as among the whole country, the lowest inci-
dence of breastfeeding occurs among young, less educated, low-income
women, and, as is true among all women, the highest incidence of
breastfeeding occurs among those Blacks with the most education and
income. (Table 2)

The proportion (54%) of Hispanic women who breastfed their in-
fants in 1983 is less than the national rate.

19


FIGURE 3- Incidence of Bred&ding USA.
9% of Infants Breaded by Race 197043

  White (Government)
r
r Black (Government)

White

70   71   72   73   74

Souras: Ros Laboratories National Mothers Survey
   National Survey Family Growth. NCHS

75   `76-77  78-79  `80-81   `82   `83

Rank

1
2
3
4
5
;
8
9
10
11
12
13

14
15
16
17
18
19

20

TABLE l- Breastfeeding by Demographics: 1983

Characteristic

Percent
breastfed 1

College . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pacific.. ....................................................................................
Momltain .................................................................................
> S25,OOO income.. ...................................................................
30 to 34 years of age.. ............................................................
25 to 29 years of age.. ............................................................
Primiparous .............................................................................
$15,000 to $24,999 income.. ...................................................
White .......................................................................................
West North Central.. ..............................................................
Not Employed ........................................................................
New England.. ........................................................................
$10,000 to $14,999 income.. ...................................................
National.. .................................................................................
Employed.. ..............................................................................
35+ years of age.. ..................................................................
East North Central.. ...............................................................
Multiparous.. ...........................................................................
West South Central.. ..............................................................
20 to 24 years of age ..............................................................

78
78
77
71
67
::
64
64
63
62
61
61
zi
60
59
58
58
57

Percent of
bi*E i 3

33
16
6
32
16
ii
26
80
8
65
5
I5

35
5
18
57
13
33


Rank

20
21
22
23
;:
26
27
28
29

Characteristic

Percent
breastfed r

South Atlantic. .........................................................................
Hispanic ...................................................................................
High School Education .........................................................
Middle Atlantic ......................................................................
East south central .................................................................
<5 lbs. 8 oz. biiweight .......................................................
< $10,000 income ....................................................................
<20 years of age.. ..................................................................
Grade School Education .......................................................
Black ........................................................................................

57
54
54
52
49
46
44
43
41
32

I

15
15
63
13
7
7
26
15
4
16

sources:

r Ross Laboratories' Mothers' Survey.
z Advance Report of Fii Natality Statistics, 198 1.
s Population Characteristics, Series P20, No. 386, April 1984 (women 18-44 years of age).

TABLE 2- Breastfeeding by Demographics among Blacks: 1983

Rank            Characteristic

1
2
3
4
5
6
7
8
9
10
11
12
13
14

15
16
17
18
19
20
21
22
23
24
25
26

Pacific ........................................................................            9      16
Mountain ...................................................................            1       6
>S25,ooO income.. .....................................................    56      13      32
College.. .....................................................................    55      22      33
New England ............................................................    54       2       5
Sl5,OOO to $24,999 income.. .....................................    45      18      26
Employed ..................................................................    41      33      35
35+ years of age ......................................................    41       4       5
West North Central.. ................................................    38               8
30 to 34 years of age ................................................    38   1:      16
25 to 29 years of age ................................................    38       24      31
Primiparous ...............................................................    38      40      43
East North Central.. .................................................    36       17      18
Middle Atlantic.. .......................................................    33      15      13
Nation01 .....................................................................    32
SlO,OOO to 814,999 income.. .....................................    31       13      15
West South Central ..................................................    31       14      13
20 to 24 years of age ................................................    30      35      33
Multiparous ...............................................................    29      61      57
(5 lbs. 8 oz. birthweight.. ........................................    28       13       7
South Atlantic.. .........................................................    27      28      15
Not Employed ..........................................................    27       67      65
Grade School Education .........................................    27       5
High School Education.. ..........................................    23      73   6':
<$lO,tXlO income.. ....................................................    20       55      26
East South Central ...................................................    20       11       7
<20 years of age ......................................................    15       25      15

              Percent
Percent   Percent
breastfed 1  of black   of all

I         births 2 s  birthsaS

sourcea:

t Ross Laboratories Mothers' Survey.
* Advance Report of Final Nirtahty Statistics, 1981.
8 Population Characteristics, Series P20, No. 386, April 1984 (women 18 to 44 yeurs of
WI.

21


The decision to breastfeed is made by well over half the women
prior to pregnancy. In 1981, 55% of breastfeeding women had made that
decision before becoming pregnant and, in 1984, that number had in-
creased to 63%. An additional 14% of breastfeeders made the decision
during their first trimester, and, by the time of delivery, 98% of breast-
feeding women had made their decision. In two prospective studies
asking women what they intended to feed their infants and subsequently
contacting them after the infant was born, 96% had implemented their
prenatal decision to breastfeed.

In summary, both the incidence and duration of breastfeeding in-
creased significantly among all segments of society from 1971 to 1982.
These gains did not continue in 1983, with the incidence dipping slightly
from 61.9% of mothers in 1982 to 61.4% in 1983. The figure remains a
function of socio-demographic variables: older, well-educated, relatively
affluent women living in the Western United States are more likely to
breastfeed; younger, less well-educated, black women in the East South
Central United States have the lowest incidence of breastfeeding. Contin-
ued gains will need to come from this latter group. Since the decision to
breastfeed is made by more than half of women before pregnancy, three
groups-the black, the young, and the poorly educated-need to be
reached early if they are to be influenced to breastfeed.

22


THE CULTURAL CONTEXT OF BREASTFEEDING
  IN THE UNITED STATES

Susan C.M. Scrimshaw, Ph.D.

Breastfeeding, Etknicity, and Socioeconomic Status

Research on breastfeeding in the U.S. reflects two biases frequently
found in medical and public health literature. First, ethnicity, and some-
times even socioeconomic status are not even mentioned in many reports.
Second, reports mentioning ethnicity and socioeconomic status often
focus on incidence without discussing correlates such as attitudes, reasons
for the observed behaviors, and the influence of sociocultural background.

The ethnic groups frequently discussed in the U.S.-Asians, Blacks,
Latinos, and Native Americans-are each in fact a complex set of dis-
tinct "sub-groups," with varying degrees of acculturation and levels of
socioeconomic status. For example, Latinos include major subgroupings
of Cubans, Puerto Ricans, Mexicans, and Mexican Americans with small-
er numbers of Dominicans, Salvadorans, Guatemalans, and many more
people from Central and South America and the Caribbean. Some La-
tinos, especially from the Caribbean and circum-Caribbean areas, are
Black and reflect influences of African cultures. While few studies make
comparisons between subcultures in relation to breastfeeding, important
differences exist. For example, in her report on feeding practices among
Anglos, Cubans, and Puerto Ricans in Dade County, Florida, Bryant re-
ports that most Puerto Ricans think breastfeeding is better for babies, but
almost half the Cuban women think bottle feeding is better.

Blacks, frequently thought of as one culture in this country, not only
divide into obvious groups like Haitians and Panamanian Blacks, but
vary in terms of parts of the country and rural or urban residence. A
rural southern Black and an urban western Black are as different from
each other as their White counterparts from the same region. Individuals
in each subcultural group are proud of their heritage; they resent being
lumped with others they perceive as dissimilar. Unfortunately, most of
the literature that does discuss breastfeeding and ethnicity does not make
these subcultural distinctions.

  Many of these variations are reduced when socioeconomic and edu-
cational statuses are considered. Baranowski et al. showed bimodal edu-
cational relationships to breastfeeding in a tri-ethnic population. Both the
least and the most educated were more likely to breastfeed. Middle- and
upper-class women are now more likely to breastfeed, although research
comparing middle- and upper-class women with lower-class women
within ethnic minority groups is conspicuous by its absence. Studies such
as Baranowski's which compared low socioeconomic status Anglo-Ameri-
cans, Black Americans, and Mexican Americans show significant differ-
ences between ethnic groups. It should be noted that Baranowski et al.
do not distinguish between Mexicans and Mexican Americans, although

23


they report that some of their Mexican American sample were inter-
viewed in English and some in Spanish.

Higher educational attainment is also correlated with breastfeeding.
Again, the effect of education within ethnic groups and subgroups has
not been adequately documented.

Frequency and Duration of Breastfeeding by Ethnic@

The data on frequency and duration of breastfeeding by ethnicity
vary greatly by region and by ethnic group. There is relatively little in-
formation on Asian populations, and even less on Native American popu-
lations. Breastfeeding in all populations declined from the beginning of
this century until the early 197Os, and Blacks may have experienced the
greatest decline. Prior to 1960, the majority of Blacks and Latinos
breastfed their first babies, and nursed longer than Whites.

The trend began to reverse in the early 197Os, but this change ap-
pears to be occurring more quickly in White than in Latino, Asian, or
Black populations. Current figures for Latinos on breastfeeding at dis-
charge from the hospital range from 18% in Upper New York State to
60% in Northern California and 74% in Southern California. Asians are
poorly represented in the literature, but Samuels reports that 67% of the
Asians in her Northern California HMO population were breastfeeding
at hospital discharge. The proportion of Blacks breastfeeding at hospital
discharge ranges from 20% in Hartford to 26% in Chicago and 52% in
Northern California. These discrepancies illustrate regional and perhaps
also rural/urban variations, but probably reflect subcultural and socio-
economic variations as well.

An example of probable variations according to socioeconomic
status is that the Blacks studied by Samuels were participants in a Kaiser
HMO as an employment benefit. Their socioeconomic status is probably
higher than that of the inner-city Blacks studied by Mohrer. The 74%
figure for Latinos in Southern California is from our project, which
looked at a population of 5 18 women, 96% Mexican in origin, 4% Mexi-
can in descent. The relatively recent Mexican origin of most of these
women probably accounts for the very high rate, and illust~:es the im-
portance of being able to distinguish between subcultures.

Duration of breastfeeding also varies, but drops off sharply after the
fust two or three months. According to Martinez and Nalezienski, in
1978 47% of all U.S. women were breastfeeding at hospital discharge,
35% were breastfeeding at two months postpartum, and 20% were
breastfeeding at six months postpartum. In one of the two Southern Cali-
fornia hospitals we studied, 86% of the Latinos (primarily Mexican)
planned to breastfeed as of their in-hospital postpartum interview, but by
the six-week postpartum visit, only 43% were still breastfeeding. On the
other hand, a greater proportion of Whites breastfed and did so longer.

24


Barriers to Breastfeeding

UNDERLYING FACTORS

Few of the underlying factors associated with bottle-feeding rather
than breastfeeding can be directly related to ethnicity, but relate instead
to socioeconomic status or are reported by women in all ethnic groups.
Cultural values, however, are likely to influence how these factors are
interpreted by women. These factors include: general perceptions of the
value of breastfeeding (mostly positive), the baby's father's feelings,
embarrassment at the exposure of the breasts, concerns about interfer-
ence with sexuality, questions about mother's temperament and suitability
for breastfeeding, anxieties about the mother's ability to produce high
quality and sufftcient milk, perception of bottles as convenient, percep-
tion of breastfeeding as old-fashioned, concerns about breastfeeding ruin-
ing the figure, and work intentions.

  In addition to socioeconomic and educational status, marital status
provides another underlying factor. Several studies show that married
women are more likely to breastfeed. The proportion of married women
giving birth varies by ethnicity, as do socioeconomic status and educa-
tional level.

One factor identified by Bryant is the husband's role. She found that
husbands were more often against breastfeeding in the Cuban and Puerto
Rican families she studied, and that Anglo husbands varied from beiig
very supportive to indifferent and sometimes negative. The husbands in
both Latin0 groups were concerned about exposure of the breasts, inter-
ference with sexual activity, and the perceived "old-fashioned" nature of
breastfeeding. This finding may appear to contradict the previously men-
tioned finding that married women are more likely to breastfeed, but
other factors such as the need to work and social isolation may influence
single women.

One perception often found in Latin0 populations is that of "bad
milk" due to maternal stress or tendency to have a temper. Mexicans,
Hondurans, Puerto Ricans, and Cubans have all described concern that
maternal anger and stress would produce bad milk, which would make
the baby sick. This concern was cited as a reason not to initiate lactation.

Another interethnic difference identified by Baranowski is the role
of the support person. The male partner was the most important breast-
feeding support person for the Anglo woman, the woman's mother was
most important to Latinos, and a close friend was most important to
Blacks. In this study, it was asserted that the woman's mother actually
had a negative effect on Anglo women.

Despite these interethnic differences, one major underlying obstacle
to breastfeeding in all groups is the woman's need to work postpartum.
While many women never even initiate breastfeeding because of postpar-
tum work plans, others simply stop sooner in order to return to work. In
our sample of 518 Mexican women, significantly fewer women planned
to breastfeed if they intended to return to work soon. The proportion
breastfeeding increased with a later return to work. The highest propor-

25