title: Breastfeeding and the risk of respiratory tract infections after infancy: The Generation R Study.
abstract: BACKGROUND
  The protection of breastfeeding against respiratory tract infections in the first year of life has often been suggested. Few studies examined the effect of breastfeeding on respiratory tract infections after infancy.
  
  
  OBJECTIVE
  To examine the association between breastfeeding with lower respiratory tract infections (LRTI) and upper respiratory tract infections (URTI) after infancy up to 4 years of age (n = 5322).
  
  
  METHODS
  This study was embedded in The Generation R study, a Dutch population-based prospective cohort study from fetal life until young adulthood. Information on breastfeeding duration (never; <3 months; 3-6 months; ≥6 months) and dose (never; partially until 4 months; predominantly until 4 months) were collected by questionnaire at 2, 6, and 12 months of age. Information on doctor attendance for LRTI and URTI were obtained by questionnaire at 2, 3, and 4 years of age.
  
  
  RESULTS
  Breastfeeding for 6 months or longer was significantly associated with a reduced risk of LRTI up to 4 years of age (aOR: 0.71; 95% CI: 0.51-0.98). Similar ORs for LRTI were found with breastfeeding for less than 3 months and 3-6 months. Although in the same direction, weaker ORs were found for URTI and breastfeeding duration. The same trend was found for partial and predominant breastfeeding until 4 months and LRTI and URTI.
  
  
  CONCLUSIONS
  Breastfeeding duration for 6 months or longer is associated with a reduced risk of LRTI in pre-school children. These findings are compatible with the hypothesis that the protective effect of breastfeeding for respiratory tract infections persist after infancy therefore supporting current recommendations for breastfeeding for at least 6 months.
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|The Department of Pediatrics, Sophia Children's Hospital, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Ilse
authors.initials: I
authors.lastname: Tromp
authors.affiliation: The Department of Pediatrics, Sophia Children's Hospital, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|The Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|The Department of Global Public Health, Leiden University College, The Hague, The Netherlands.
authors.forename: Jessica
authors.initials: J
authors.lastname: Kiefte-de Jong
authors.affiliation: The Department of Public Health, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Hein
authors.initials: H
authors.lastname: Raat
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|The Department of Pediatrics, Sophia Children's Hospital, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|The Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jaddoe
authors.affiliation: The Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Oscar
authors.initials: O
authors.lastname: Franco
authors.affiliation: The Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: The Department of Pediatrics, Sophia Children's Hospital, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Johan
authors.initials: J
authors.lastname: de Jongste
authors.affiliation: The Department of Pediatrics, Sophia Children's Hospital, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Henriëtte
authors.initials: H
authors.lastname: Moll
mesh_terms: D001942:Breast Feeding; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000517:prevention & control*; D012306:Risk; D013997:Time Factors