1. Breast Feeding & Asthma :Should
we promote breast feeding?
It is not controversial that breast-feeding
is the preferred method of infant nutrition
because of its nutritional, immunological,
and psychological benefits
Effects on reducing early childhood wheezing,
GI tract infections and atopic eczema (in early
life) was demonstrated by several studies
Effects on childhood asthma is controversial
especially in mother who has asthma
Friedman et al.JACI 2005 -

2. Sicherer et al.JACI 2008 -

4. Does breastfeeding protect
against development of
atopy & asthma in childhood
?
Objective
To assess long-term outcomes of asthma &
atopy related to breastfeeding in a New Zealand
birth cohort study

5. Large unselected population-based birth cohort study
SPT
aeroallergen
FH of allergy
69% 87%
1,037 (91%) of
1,661 1,139 kids who
live-born were in Otago 5 7 9 11 13 15 18 21 26 yr
at age 3 y
Comprehensive Questionnaire
Verify BF Spirometry
record
(investigators Metacholine challenge/
unaware of Bronchodilator response test
outcome)
Investigators unaware of data for infant feeding determined all respiratory outcomes

6. Methods
• Current asthma = positive response to
question “Do you (does your child) have
asthma?” together with symptoms
reported within previous 12 mo
• SPT to Dp, cat, dog , horse hair, rye
grass, kapok, wool, fungus (positive =
wheal > 2 mm than negative control at
15 min)

7. Results
• 1,037 kids  early childhood characteristics not
differ from 102 kids who did not participate
• 45% (463) not breastfed
• 7% (70) kids discontinued breastfed before 4 wk
51% (533) BF < 4 wk
49% (504) BF >= 4 wk
• Mean duration of BF in BF group = 21.1 wk (SD
16.6)
• Term “BF” not necessarily mean exclusive BF

8. Results
• 1,037 kids  early childhood characteristics not
differ from 102 kids who did not participate
• 45% (463) not breastfed
• 7% (70) kids discontinued breastfed before 4 wk
51% (533) BF < 4 wk preliminary
report : bias??
49% (504) BF >= 4 wk
• Mean duration of BF in BF group = 21.1 wk (SD
16.6) : 4 wk until 47 wk
• Term “BF” not necessarily mean exclusive BF

9. Characteristics of BF group
• First-born Bias?
• Higher socioeconomic status
• Non-smoking mothers
• More likely to have a sheepskin on their bed
• Family history of hayfever or asthma (mother or father)
and sex did not differ to non-BF group

10. The effect with current asthma persisted
at all ages to 26 years

12. Effect of BF not effected by FH

13. 1.72 --- 1.91 1.53 1.55
2.09 --- 2.54 1.86 1.73

14. Adjust SES, birth order, sheepskin use in infancy, maternal smoking

15. Conclusion
• No duration of exclusive BF had a protective effect
against development of atopy & asthma in later
childhood
• BF > 4 wks likelihood of skin test response to
common allergens at age 13 y and more than
doubled the risk of diagnosed asthma in mid-
childhood, with effects persisting into adulthood
• Role of BF in protection of kids against atopy &
asthma cannot be supported

16. Appraising the Controversy
&
A Rebuttal
Pete et al.Pediatric Pulmonology 2003.35:331-4
Sear et al.Pediatric Pulmonology 2003:36:366-8

17. Issues
1. Heterogenicity of breast feeding
groups
2. Recall bias & unclear whether recalled
reported were adjusted when the two
methods differed
3. Reporting bias : most mothers aware
that a longer duration of breastfeeding
is desirable

18. Answers
Breast feeding data was recorded systematically by
interviewers at 3 years old and were compared with data
recorded prospectively by nurse with 98.9% agreement
When data from nurse records were not provided : authors
said they analyzed that it is not recall bias (how to?)
Giving mothers the benefit of the doubt would not lead to
any significant difference in outcomes (how to show?)

19. 4. Selection bias : hospital-based cohort
& European ethnics only
5. Confounding factors
6. Causality : no dose response effect

22. Population-based birth cohort study
Access
early childhood
Ask whether
wheezing diagnosed asthma
14,062 13,978 alive
live 3 4 7 8
births at age 1 y
Verify BF SPT
record aeroallergen
Spirometry &
Metacholine challenge

23. Methods
2 populations were accessed :
- BF (never, < month, to < months,
to < months, and >= months)
- Exclusive breast-feeding (never,< months,
>= months)
SPT to 3 core aeroallergens (cat, mixed
grass pollen, house dust mite)
- positive >= 2 mm than negative control at 15
min)

26. 71.5 %
Adjusted by sex, maternal age, maternal smoking, environmental tobacco smoke
, maternal asthma, maternal allergy, and older siblings

27. 57 %
Maternal age and maternal history of allergy : most important confounders

28. 55 %

29. Results
Slightly protective effect of breast feeding
on wheeze in early life did not extend into
later childhood which is consistent with
most other studies
However no evidence of deleterious effect
of breast feeding on atopic sensitization and
later wheezing

30. Results
• Bayesian joint model (reverse causation
effect, loss follow-up group)
• Reverse causation effect = children
with early wheezing were more likely
to be breast-fed longer and to have
allergic outcomes
• Mean duration of breast-feeding for children
who did not wheeze in the first months of life
was . months compared with . months for
children with wheeze (P < .

31. Results
• modest difference in duration of breast-feeding
based on early infant wheezing was not
sufficient to bias the relationships between
breast-feeding and the health outcomes
examined
• No evidence that the pattern of missing data in
this study appreciably influenced outcome

32. Benefits
• Large birth cohort study
• Objective measurement
• Bayesian joint model
Weakness
• High drop-out rate
• Criteria definition of atopy

33. Even breast feeding does not protect
asthma or atopy in later life
Breastfeeding is a natural
phenomenon, providing balanced nutrition
and mother–infant bonding, as well as a
number of health benefits
Breast feeding is still preferable method
for infantile feeding