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Introduction to Lactation
Or
“So That’s What They’re for!”
In this Lecture we will discuss:
• Why learn about
breastfeeding
• Anatomy &
Physiology of
Breastfeeding
• Immunology of BF
• Why BF is Good
• Info on HIV &BF
Developing World: Preventing
Infant Death
• 10 million children die each year in the
developing world, - 60% are preventable.
• LANCET (2003) Suggested “optimal
breastfeeding behaviours” could prevent
13% of deaths, or save 1.3 million
children annually.
• Most effective health intervention!
*Determined using data from the 42 countries that had 90% of the
child deaths worldwide in 2000, by estimating the impact of
universal coverage with each individual intervention.
Measure to Prevent Infant Deaths
Preventive Estimated Percent of all
deaths deaths
Intervention prevented
(thousands)
Breastfeeding 1,301 13%
Insecticide Rx
material 691 7%
Complementary
Feeding 587 6%
Measure to Prevent Infant Deaths
Preventive Estimated Percent of all
deaths deaths
Intervention prevented
(thousands)
Clean childbirth 411 4%
Clean Water,
sanitation 326 3%
Nevirapine and
replacement 150 2%
feeding
Bottle Feeding Costs Society
• British National Health Survey estimated that 1%
rise in BF would save system 500,000 pounds/yr
• Australia Economic analysis (97) –20%BF
increase saves $11.5 million.
• Tucson HMO formula fed babies had 2033 more
visits, 212 more hospital days & 609 more
prescriptions ($331-475/child in first yr)
• Kaiser (94-95) Increased BF saved
$1435.00/child
• In developed
countries the
increase in infant
mortality attributable
to artificial feeding is
4/1000..
• Deaths attributable
to artificial feeding
160/year.
• - SIDS deaths in
Quebec
40/year.
- Fatal MVA’s
100/year
In this Lecture we will discuss:
• Why learn about
breastfeeding
• Anatomy &
Physiology of
Breastfeeding
• Immunology of BF
• Why BF is Good
• New info on HIV &BF
Embryology
• Ectodermal duct system
• Mesodermal fat
• Vascular system
Cyclic Changes
• Estrogen
– Leads to proliferation and maturation of
the epithelial cells
Progesterone
Leads to increase in acinar size and
secretion of acinar fluid and increased
stromal edema
Anatomy
• The breast is an acinar gland
– It is made up of secretory units with a ductal
system and alveoli
• It is a modified sebaceous gland
– i.e. an Apocrine gland secreting its contents
through a duct to a specific target
Lactogenesis: Pregnancy
• During pregnancy high levels of estrogen
extends and modifies the ductal system
• Progesterone develops the alveolar system
• The nipple becomes prominent and
hyperpigmented
• The vascular system increases in size and flow,
• The Montgomery tubercles increase & secrete a
lubricating fluid
Prolactin
• Is usually tonically inhibited by
hypothalamic dopamine
• With pregnancy blood levels rise from
normal 25ng/ml to a high of 200-400 ng/ml
? 2ndy to high estrogens
• GnRh and vasopressin angiotensin II
increase prolactin
Parturition
• Sudden fall in
progesterone,
Estrogen and HPL
releases breast
from inhibition
• Oxytocin release
contract both
uterus and
myoepithelial cells
of the breast acinii
Lactogenesis II
• Colostrum is the initial breast secretion
• Colostrum turns into milk over the 2-3 days after
birth needs prolactin
• This involves increase in lactose, lactalbumen
casein and fat
• By 6-8 weeks supply is dependant on removal of
milk i.e. is relatively free of endocrine control
The Good Latch
A Really Bad Latch!
In this Lecture we will discuss:
• Why learn about
breastfeeding
• Anatomy &
Physiology of
Breastfeeding
• Immunology of BF
• Why BF is Good
• New info on HIV &BF
Immunological agents that are
“developmentally delayed” in infancy and
that are provided by human milk
Anti-inflammatory
• Lactoferrin
Antimicrobial • Lysozyme
• Lactoferrin • Secretory IgA
• IL-10
• Lysozyme • PAF-acetylhydrolase
• Secretory IgA
Immunomodulatory
• Memory T cells • Secretory IgA
• Antibodies to T-cell- • Interferon-g
independent antigens • IL-8
• IL-10
Anatomy of Breastmilk:
a living colloidal suspension produced by the
mother’s body to address the changing needs
of the child in the environment
Cellular Non-cellular
• T- and B-Lymphocytes • Immunoglobulins
• Neutrophils • Enzymes
• Macrophages • Inhibitors of metabolism, e.g.,
• Epithelial cell activity lactoferrin
• Carrier Proteins
• Oligosaccharides.
• Hormones and hormone-like
substances, e.g., Human milk growth
factors
• Anti-inflammatory factors
• Glycosylated proteins
• Nonspecific Factors
• Immunomodulating agents
• Additional Viral Fighting Factors,
such as Antiviral lipids
Colostrum/Breastmilk &
Immunity
• The immunity in the milk continues to
respond in a dynamic fashion throughout
the period of lactation
Do Bottle Fed Babies Suffer an
Acquired Immune Deficiency?
• It is perhaps…
In this Lecture we will discuss:
• Why learn about
breastfeeding
• Anatomy &
Physiology of
Breastfeeding
• Immunology of BF
• Why BF is Good
• New info on HIV &BF
Breastfeeding Is Good
Breastfeeding Is Good:for
Babies
• Decreases incidence &virulence of diarrhea,
otitis media and respiratory infections,
decreases asthma
• Decreased incidence of IDDM, in aboriginals
decreases NIDDM in childhood
• Associated with decreased SIDS & childhood
leukemias
• In Belarus RCT babies from high breastfeeding
hospitals do better on neuro-psych tests in
grade 1
Extensive study in the last
decade:SURVIVAL
• 2001 Arifeen et al Bangladesh N=1677
prospective obs.
– Compared to EBF, other patterns had 2.23-fold risk of
death, 2.4 fold from ARI and 3.94 from diarrhoea
• 2001 Bertran et al 15 national surveys
– 55% of diarrhea and ARI deaths could be prevented
by EBF for at least 3 months with continued BF
• 2002 Coutsoudis et al South Africa
– Reduces HIV transmission via breastfeeding by half
• 2004 Chen and Rogan USA
– 20% reduction in postneonatal mortality
with BF
Breastfeeding and infant illness: a dose-
response relationship
Raisler J, Alexander C, O’Campo P.
American Journal of Public health 1999: 89, 1 p25-30
• Compared with no breastfeeding, full
breastfeeding infants have lower odds ratios of
Diarrhea cough or wheeze, and vomiting. They
had lower mean months of illness and fewer
sick baby doctors visits.
• This effect decreased as the dose of
breastmilk relative to formula decreased.
Findings did not vary by income.
Is Good for Babies after weaning
Breastfeeding and future health
Lene Schack-Nielsen and Kim Fleischer Michaelsen
Curr Opin Clin Nutr Metab Care 9:289–296. _ 2006
-The positive effect of breast feeding on later
cognitive
function continues to be the most consistent and
important effect.
-breast feeding is likely to protect against some
immune-related diseases later in life, such as type 1
diabetes, coeliac disease, inflammatory bowel
diseases and perhaps cancer.
Results of Studies on Lactational Amenorrhea
Method of Contraception: Efficacy
by 6 (or 9) Month Life Table
100
95
90 99.6 98.8 99 99.4 100 98.5 100 99.5
96.5
85
%80
9-Month
Marketing
Multicenter
Working
Chile 1
Philippines
Pakistan
Ecuador
Zealand
New
Post-
Breastfeeding Is Good: for Babies
• Encourages formation
of strong teeth and
proper oral anatomy
Abnormal Palate
Breastfeeding is Good for Women
• New study from Nurses Health trial –JAMA
2005
• Dose related protection of women from
Type 2 Diabetes increasing with length of
of breastfeeding
• Independent of BMI
M
c
0.2
0.4
0.6
0.8
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1.4
1.6
1.8
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yg e
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Among Women Who Breastfed
Tr ir
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2
Risk of Pre-Menopausal Breast Cancer
Jernstrom et al –July 24, 2004
• Patients with the BRCA1 mutation have a
life-time risk of breast ca apx. 80-85%
• Women who breastfed for over 1 year
were significantly protected from the risk of
breast cancer p greater than .001
• Each additional month of breastfeeding
decreased risk by 2%
In this Lecture we will discuss:
• Why learn about
breastfeeding
• Anatomy &
Physiology of
Breastfeeding
• Immunology of BF
• Why BF is Good
• New info on HIV &BF
Colostrum/Breastmilk &
Immunity
• The immunity in the milk continues to
respond in a dynamic fashion throughout
the period of lactation
• “Instead of considering human milk as a
food that contains antibodies, it perhaps
better to think of it as a solution of
biologically protective ingredients with
nutritional side-effects”
Newburg, JPediatr Gastroenterol Nutr 30 (S2): S16 2000
Cumulative probability of HIV among
549 children born to HIV+ women
Coutsoudis et al. AIDS 2001, 15:379-87
• Exclusively
45
40
breastfed group ( )
35 is statistically
30 significantly
25
different from
20
15
mixed fed ( ), but is
10 not statistically
5 significantly
0
different from never
o
o
o
o
ks
h
m
m
breastfed ( )group
m
m
irt
w
3
6
B
12
15
6
until 15 months,
controlling for 15
variables.
Breastfeeding Plus Infant Zidovudine Prophylaxis for 6
Months vs Formula Feeding Plus Infant Zidovudine for 1
Month to Reduce Mother-to-Child HIV Transmission in
Botswana, A Randomized Trial: The Mashi Study
Thior et al 2006
Conclusions:
-Breastfeeding with AZT was not as effective as formula in
preventing postnatal HIV transmission
-But was associated with a lower mortality rate at 7 months.
-Both strategies had comparable HIV-free survival at
18months.
-These results demonstrate the risk of formula feeding to
infants in sub-Saharan Africa.
Which Should We Choose?
Breastfeeding Plus Infant Zidovudine Prophylaxis for 6
Months vs Formula Feeding Plus Infant Zidovudine for 1
Month to Reduce Mother-to-Child HIV Transmission in
Botswana,
A Randomized Trial: The Mashi Study Thior et al 2006
Conclusions:
- Breastfeeding with AZT was not as effective as
formula in preventing postnatal HIV transmission
- However had a lower mortality rate at 7 months.
- HIV status in both arms the same at 18months.
These results demonstrate the risk of formula
feeding to infants in sub-Saharan Africa.
In Conclusion
• The Breast is an
apocrine gland
• E&P develop the
lactating breast
• Lactation is under
dual control:
Oxytocin – removes
Prolactin-makes
more
In Conclusion
• The immune
system of babies
is jump-started
and modified by
the mother’s milk
• Mother’s milk
responds in a
dynamic fashion to
protect the
nursling
Breastfeeding is Good
Colostrum/Breastmilk &
Immunity
• The immunity in the milk continues to
respond in a dynamic fashion throughout
the period of lactation
• “Instead of considering human milk as a
food that contains antibodies, it perhaps
better to think of it as a solution of
biologically protective ingredients with
nutritional side-effects”
Newburg, JPediatr Gastroenterol Nutr 30 (S2): S16 2000
Breastfeeding Plus Infant Zidovudine Prophylaxis for 6
Months vs Formula Feeding Plus Infant Zidovudine for
1 Month to Reduce Mother-to-Child HIV Transmission
in Botswana, A Randomized Trial: The Mashi Study
Thior et al 2006
Conclusions:
- Breastfeeding with AZT was not as effective as
formula in preventing postnatal HIV transmission
-But was associated with a lower mortality rate at 7
months.
-Both strategies had comparable HIV-free survival at
18months.
-These results demonstrate the risk of formula
feeding to infants in sub-Saharan Africa.
