title: Effects of Breastfeeding on Respiratory Symptoms in Infancy.
abstract: OBJECTIVE
  To assess the impact of potential risk factors on the development of respiratory symptoms and their specific modification by breastfeeding in infants in the first year of life.
  
  
  METHODS
  We prospectively studied 436 healthy term infants from the Bern-Basel Infant Lung Development cohort. The breastfeeding status, and incidence and severity of respiratory symptoms (score) were assessed weekly by telephone interview during the first year of life. Risk factors (eg, pre- and postnatal smoking exposure, mode of delivery, gestational age, maternal atopy, and number of older siblings) were obtained using standardized questionnaires. Weekly measurements of particulate matter <10 μg were provided by local monitoring stations. The associations were investigated using generalized additive mixed model with quasi Poisson distribution.
  
  
  RESULTS
  Breastfeeding reduced the incidence and severity of the respiratory symptom score mainly in the first 27 weeks of life (risk ratio 0.70; 95% CI 0.55-0.88). We found a protective effect of breastfeeding in girls but not in boys. During the first 27 weeks of life, breastfeeding attenuated the effects of maternal smoking during pregnancy, gestational age, and cesarean delivery on respiratory symptoms. There was no evidence for an interaction between breastfeeding and maternal atopy, number of older siblings, child care attendance, or particulate matter <10 μg.
  
  
  CONCLUSIONS
  This study shows the risk-specific effect of breastfeeding on respiratory symptoms in early life using the comprehensive time-series approach.
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Basel, Switzerland.
authors.forename: Olga
authors.initials: O
authors.lastname: Gorlanova
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Basel, Switzerland.
authors.forename: Simone
authors.initials: S
authors.lastname: Thalmann
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Basel, Switzerland; Pediatric Respiratory Medicine, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Proietti
authors.affiliation: Pediatric Respiratory Medicine, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Georgette
authors.initials: G
authors.lastname: Stern
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Basel, Switzerland; Pediatric Respiratory Medicine, Inselspital and University of Bern, Bern, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Latzin
authors.affiliation: Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
authors.forename: Claudia
authors.initials: C
authors.lastname: Kühni
authors.affiliation: Swiss Tropical and Public Health Institute, University of Basel, Basel, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
authors.affiliation: University Children's Hospital (UKBB), University of Basel, Basel, Switzerland. Electronic address: urs.frey@ukbb.ch.
authors.forename: Urs
authors.initials: U
authors.lastname: Frey
mesh_terms: D001942:Breast Feeding; D003371:Cough / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016012:Poisson Distribution; D011446:Prospective Studies; D012120:Respiration Disorders / Q000453:epidemiology* / Q000517:prevention & control; D012135:Respiratory Sounds; D012307:Risk Factors
keywords: breastfeeding; infants; interaction; longitudinal study; respiratory symptoms