title: The association between caesarean section and childhood obesity revisited: a cohort study.
abstract: BACKGROUND
  The mode of delivery has recently gained attention as another potential perinatal risk factor for childhood obesity but results are conflicting.
  
  
  OBJECTIVE
  To examine whether caesarean section is independently associated with childhood obesity after adjusting for a broad range of confounding factors.
  
  
  METHODS
  The current study used a population-based survey in Grade 5 students linked to a provincial perinatal registry in the Canadian province of Nova Scotia. Associations between caesarean section and childhood overweight and obesity at age 10/11 years were examined using multiple logistic regression.
  
  
  RESULTS
  Of the 4298 students who participated in the 2003 Children's Lifestyle and School Performance Study (response rate 51.1%), 3426 (80%) could be linked with information in the Atlee Perinatal Database, and 2988 mother-child pairs (70%) had complete information on the exposure and outcome. Compared to vaginal delivery, caesarean section was associated with offspring obesity (OR) 1.49, 95% CI 1.10 to 2.00) in the univariate analysis. After adding maternal prepregnancy weight to the multiple regression model, the OR for obesity dropped from 1.48 to 1.20 (95% CI 0.87 to 1.65). When caesarean section with and without labour were considered separately, we found no statistically significant associations relative to the vaginal delivery group (OR 1.24, 95% CI 0.84 to 1.82 and OR 1.03, 95% CI 0.58 to 1.84).
  
  
  CONCLUSIONS
  Our results do not support a causal association between caesarean section and childhood obesity. Maternal prepregnancy weight was an important confounder in the association between caesarean delivery and childhood obesity and needs to be considered in future studies.
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Obstetrics & Gynaecology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Kelli
authors.initials: K
authors.lastname: Flemming
authors.forename: Christy G
authors.initials: CG
authors.lastname: Woolcott
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Allen
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Veugelers
authors.forename: Stefan
authors.initials: S
authors.lastname: Kuhle
mesh_terms: D000328:Adult; D001835:Body Weight; D002170:Canada; D002585:Cesarean Section / Q000706:statistics & numerical data*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008019:Life Style; D016015:Logistic Models; D008297:Male; D009674:Nova Scotia; D009765:Obesity / Q000453:epidemiology*; D011247:Pregnancy; D012307:Risk Factors
keywords: Cesarean section; Child; Epidemiology; Obesity