title: Effect of prolonged and exclusive breast feeding on risk of allergy and asthma: cluster randomised trial.
abstract: 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].
authors.affiliation: Department of Pediatrics, McGill University Faculty of Medicine, Montreal, Canada. michael.kramer@mcgill.ca
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
authors.forename: Lidia
authors.initials: L
authors.lastname: Matush
authors.forename: Irina
authors.initials: I
authors.lastname: Vanilovich
authors.forename: Robert
authors.initials: R
authors.lastname: Platt
authors.forename: Natalia
authors.initials: N
authors.lastname: Bogdanovich
authors.forename: Zinaida
authors.initials: Z
authors.lastname: Sevkovskaya
authors.forename: Irina
authors.initials: I
authors.lastname: Dzikovich
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Shishko
authors.forename: Bruce
authors.initials: B
authors.lastname: Mazer
mesh_terms: 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