Effect of prolonged and exclusive breast feeding on risk of allergy and asthma: cluster randomised trial.
OBJECTIVE
To assess whether exclusive and prolonged breast feeding reduces the risk of childhood asthma and allergy by age 6.5 years.


METHODS
Cluster randomised trial.


METHODS
31 Belarussian maternity hospitals and their affiliated polyclinics.


METHODS
A total of 17,046 mother-infant pairs were enrolled, of whom 13,889 (81.5%) were followed up at age 6.5 years.


METHODS
Breastfeeding promotion intervention modelled on the WHO/UNICEF baby friendly hospital initiative.


METHODS
International study of asthma and allergies in childhood (ISAAC) questionnaire and skin prick tests of five inhalant antigens.


RESULTS
The experimental intervention led to a large increase in exclusive breast feeding at 3 months (44.3% v 6.4%; P<0.001) and a significantly higher prevalence of any breast feeding at all ages up to and including 12 months. The experimental group had no reduction in risks of allergic symptoms and diagnoses or positive skin prick tests. In fact, after exclusion of six sites (three experimental and three control) with suspiciously high rates of positive skin prick tests, risks were significantly increased in the experimental group for four of the five antigens.


CONCLUSIONS
These results do not support a protective effect of prolonged and exclusive breast feeding on asthma or allergy.


BACKGROUND
Current Controlled Trials ISRCTN37687716 [controlled-trials.com].
Kramer
Michael S
MS
Department of Pediatrics, McGill University Faculty of Medicine, Montreal, Canada. michael.kramer@mcgill.ca
Matush
Lidia
L
Vanilovich
Irina
I
Platt
Robert
R
Bogdanovich
Natalia
N
Sevkovskaya
Zinaida
Z
Dzikovich
Irina
I
Shishko
Gyorgy
G
Mazer
Bruce
B
D001249:Asthma / Q000517:prevention & control; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D006293:Health Promotion; D006801:Humans; D006967:Hypersensitivity / Q000517:prevention & control*; D007223:Infant; D007231:Infant, Newborn; D008485:Medical Audit; D010375:Pedigree; D012307:Risk Factors; D012882:Skin Tests; D013997:Time Factors