title: Breast-feeding does not protect against allergic sensitization in early childhood and allergy-associated disease at age 7 years.
abstract: BACKGROUND
  Extended breast-feeding is recommended for newborn children at risk of allergy-associated diseases, but the evidence of a protective effect on sensitization and these diseases remains elusive.
  
  
  OBJECTIVE
  The aim of this study was to investigate the effects of the duration of exclusive breast-feeding on the development of sensitization in preschool children.
  
  
  METHODS
  Information on breast-feeding was gathered by interviews involving 335 children aged 1, 6, and 12 months from the Copenhagen Prospective Study on Asthma in Childhood2000 birth cohort born to mothers with a history of asthma. Skin prick test responses and specific IgE levels against 12 common inhalant and 10 food allergens were assessed longitudinally at ages ½ year, 1½ years, 4 years, and 6 years. Eczema, wheeze/asthma, and allergic rhinitis were diagnosed at the Copenhagen Prospective Studies on Asthma in Childhood clinic at 7 years of age, strictly adhering to predefined algorithms. Associations between duration of exclusive breast-feeding and outcomes were analyzed by logistic regression.
  
  
  RESULTS
  We found no significant association between duration of exclusive breast-feeding and development of sensitization in the first 6 years of life (odds ratio [OR]: ½ year, 1.10 [95% CI, 0.90-1.36]; 1½ years, 1.15 [95% CI, 0.97-1.36]; 4 years, 1.08 [95% CI, 0.93-1.25]; and 6 years, 0.96 [95% CI, 0.84-1.10]) or with current eczema, wheeze/asthma, and allergic rhinitis at age 7 years (OR, 1.07 [95% CI, 0.92-1.24]; OR, 0.97 [95% CI, 0.82-1.14]; and OR, 1.02 [95% CI, 0.84-1.23], respectively). Adjusting for reverse causation by excluding children with eczema, wheeze, or a positive skin prick test response before ending exclusive breast-feeding did not alter the results.
  
  
  CONCLUSIONS
  Exclusive breast-feeding does not affect sensitization in early childhood or associated diseases at 7 years of age in at-risk children.
authors.affiliation: Copenhagen Prospective Studies on Asthma in Childhood, Faculty of Health and Medical Sciences, University of Copenhagen & Danish Pediatric Asthma Center, Gentofte Hospital, University of Copenhagen, Gentofte, Denmark.
authors.forename: Ea
authors.initials: E
authors.lastname: Jelding-Dannemand
authors.affiliation: Copenhagen Prospective Studies on Asthma in Childhood, Faculty of Health and Medical Sciences, University of Copenhagen & Danish Pediatric Asthma Center, Gentofte Hospital, University of Copenhagen, Gentofte, Denmark.
authors.forename: Ann-Marie
authors.initials: AM
authors.lastname: Malby Schoos
authors.affiliation: Copenhagen Prospective Studies on Asthma in Childhood, Faculty of Health and Medical Sciences, University of Copenhagen & Danish Pediatric Asthma Center, Gentofte Hospital, University of Copenhagen, Gentofte, Denmark. Electronic address: bisgaard@copsac.com.
authors.forename: Hans
authors.initials: H
authors.lastname: Bisgaard
mesh_terms: D000465:Algorithms; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D008297:Male; D011446:Prospective Studies
chemical_list: D007073:Immunoglobulin E
keywords: Breast-feeding; asthma; children; eczema; sensitization; skin prick test; specific IgE