title: Birth-related factors and doctor-diagnosed wheezing and allergic sensitization in early childhood.
abstract: BACKGROUND
  To investigate the associations between clinical obstetric factors during birth and doctor-diagnosed wheezing and allergic sensitization during early childhood.
  
  
  METHODS
  We followed 410 Finnish women from late pregnancy until 18 months age of their children. All children were delivered at term. Doctor-diagnosed wheezing among children was established by questionnaires, while specific immunoglobulin E antibodies to inhalant and food allergens were measured in 388 children at 1 year of age. Data on maternal obstetric variables were recorded at the time of delivery.
  
  
  RESULTS
  Children of mothers with longer duration of ruptured fetal membranes before birth had significantly higher risk of doctor-diagnosed wheezing during early childhood compared to those children with shorter period of ruptured fetal membranes (III vs I quartile; aOR 6.65, 95% CI 1.99-22.18; P < 0.002 and IV vs I quartile; aOR 3.88, 95% CI 1.05-14.36, P < 0.043). Children who were born by Cesarean delivery had significantly less allergic sensitization at the age of 1 year compared to those who were born by vaginal route (16.0%vs 32.2%; aOR 0.34, 95% CI 0.14-0.80; P < 0.013). Furthermore, allergic sensitization tended to be more common in children with longer duration of labor before birth. No other birth-related obstetric factors, such as induction, the type of fetal membrane rupture during birth or quality of amniotic fluid were associated significantly with the examined outcomes.
  
  
  CONCLUSIONS
  The longer duration of the ruptured fetal membranes possibly reflected the higher risk of intrapartum infection at birth, and further increased the risk of doctor-diagnosed wheezing among offspring.
authors.affiliation: Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland. leea.keski-nisula@kuh.fi
authors.forename: L
authors.initials: L
authors.lastname: Keski-Nisula
authors.forename: A
authors.initials: A
authors.lastname: Karvonen
authors.forename: P I
authors.initials: PI
authors.lastname: Pfefferle
authors.forename: H
authors.initials: H
authors.lastname: Renz
authors.forename: G
authors.initials: G
authors.lastname: Büchele
authors.forename: J
authors.initials: J
authors.lastname: Pekkanen
mesh_terms: D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000276:immunology; D002585:Cesarean Section; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology*; D005387:Finland / Q000453:epidemiology; D005512:Food Hypersensitivity / Q000175:diagnosis; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D007073:Immunoglobulin E; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012135:Respiratory Sounds / Q000175:diagnosis*; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D007073:Immunoglobulin E