title: Evaluation of the associations between childhood asthma and prenatal and perinatal factors.
abstract: OBJECTIVE
  To identify prenatal and perinatal risk factors for childhood asthma.
  
  
  METHODS
  A retrospective case-control study was undertaken among children aged 7-14 years in Tehran, Iran, between March 2009 and November 2014. Data for children with asthma (Iranian nationality, non-smoking parents, and middle-class socioeconomic status) were compared with those for an equal number of age- and sex-matched non-asthmatic children. Prenatal and perinatal risk factors were evaluated via complete data sheets of maternal pregnancy and delivery. Forward logistic regression analysis was performed.
  
  
  RESULTS
  Both groups contained 134 children. Risk of asthma was shown to be associated with maternal history of asthma (adjusted odds ratio [aOR] 11.62, 95% confidence interval 1.38-96.93; P=0.024), vaginal bleeding during pregnancy (aOR 3.76, 95% CI 1.86-7.57; P<0.001), antibiotics during pregnancy (aOR 3.19, 95% CI 1.52-6.67; P=0.002), and maternal age 30 years or older (aOR 2.54, 95% CI 1.30-4.95; P=0.006). Breastfeeding was protective against childhood asthma (aOR 0.29, 95% CI 0.151-0.575; P<0.001).
  
  
  CONCLUSIONS
  History of maternal asthma was the most influential factor on development of childhood asthma, followed by vaginal bleeding during pregnancy, antibiotic exposure in utero, and older maternal age.
authors.affiliation: Department of Obstetrics and Gynecology, Iran University of Medical Sciences, Akbarabadi Teaching Hospital, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Kashanian
authors.affiliation: Department of Obstetrics and Gynecology, Iran University of Medical Sciences, Akbarabadi Teaching Hospital, Tehran, Iran.
authors.forename: Seyyedeh Samaneh
authors.initials: SS
authors.lastname: Mohtashami
authors.affiliation: Department of Pediatrics, Iran University of Medical Sciences, Hazrate Rasool Akram Teaching Hospital, Tehran, Iran.
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Bemanian
authors.affiliation: Department of Internal Medicine, Iran University of Medical Sciences, Hazrate Rasool Akram Teaching Hospital, Tehran, Iran.
authors.forename: Seyyed Ali Javad
authors.initials: SAJ
authors.lastname: Moosavi
authors.affiliation: Department of Community Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Maziar
authors.initials: M
authors.lastname: Moradi Lakeh
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology* / Q000517:prevention & control; D001942:Breast Feeding; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Asthma; Childhood; Maternal factors; Neonate; Perinatal factors; Pregnancy; Prematurity; Prenatal factors