title: Neonatal antibiotic treatment is a risk factor for early wheezing.
abstract: OBJECTIVE
  The use of antibiotics in infancy and subsequent changes in the intestinal bacterial flora have been discussed as risk factors for the development of asthma. However, it has been difficult to exclude the possibility that antibiotics have been given in early episodes of wheezing. As a result, there has been a risk of reverse causation. To minimize the risk of reverse causation, we have focused on the effect of antibiotics that are already administered on the neonatal ward.
  
  
  METHODS
  In a cohort study of infants born in western Sweden in 2003, we studied the development of wheezing. The families of the infants were randomly selected and sent a questionnaire at child ages 6 and 12 months. The response rate was 68.5% to the 6-month questionnaire and 68.9% to the 12-month questionnaire.
  
  
  RESULTS
  At 12 months, 20.2% of infants had had 1 or more episodes of wheezing, and 5.3% had had 3 or more episodes. Inhaled corticosteroids had been taken by 4.1% of the infants. Independent risk factors for wheezing disorder treated with inhaled corticosteroids were neonatal antibiotic treatment, male gender, gestational age of <37 weeks, having a mother with asthma, having a sibling with asthma or eczema, and breastfeeding for <5 months.
  
  
  CONCLUSIONS
  Treatment with antibiotics in the neonatal period was an independent risk factor for wheezing that was treated with inhaled corticosteroids at 12 months of age. These results indirectly support the hypothesis that an alteration in the intestinal flora can increase the risk of subsequent wheezing.
authors.affiliation: Department of Pediatrics, Göteborg University, Queen Silvia Children's Hospital, SE-416 85 Göteborg, Sweden. bernt.alm@medfak.gu.se
authors.forename: Bernt
authors.initials: B
authors.lastname: Alm
authors.forename: Laslo
authors.initials: L
authors.lastname: Erdes
authors.forename: Per
authors.initials: P
authors.lastname: Möllborg
authors.forename: Rolf
authors.initials: R
authors.lastname: Pettersson
authors.forename: S Gunnar
authors.initials: SG
authors.lastname: Norvenius
authors.forename: Nils
authors.initials: N
authors.lastname: Aberg
authors.forename: Göran
authors.initials: G
authors.lastname: Wennergren
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000367:Age Factors; D017668:Age of Onset; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001249:Asthma / Q000139:chemically induced* / Q000188:drug therapy / Q000453:epidemiology*; D001997:Bronchopulmonary Dysplasia / Q000175:diagnosis / Q000188:drug therapy*; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D011336:Probability; D012135:Respiratory Sounds / Q000503:physiopathology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
chemical_list: D000305:Adrenal Cortex Hormones; D000900:Anti-Bacterial Agents