title: Cesarean delivery is associated with an increased risk of obesity in adulthood in a Brazilian birth cohort study.
abstract: BACKGROUND
  Obesity is epidemic worldwide, and increases in cesarean delivery rates have occurred in parallel.
  
  
  OBJECTIVE
  This study aimed to determine whether cesarean delivery is a risk factor for obesity in adulthood in a birth cohort of Brazilian subjects.
  
  
  METHODS
  We initiated a birth cohort study in Ribeirão Preto, southeastern Brazil, in 1978. A randomly selected sample of 2057 subjects from the original cohort was reassessed in 2002-2004. Type of delivery, birth weight, maternal smoking, and schooling were obtained after birth. The following data from subjects were collected at 23-25 y of age: body mass index (BMI; in kg/m(2)), physical activity, smoking, and income. Obesity was defined as a BMI ≥30. A Poisson multivariable model was performed to determine the association between cesarean delivery and BMI.
  
  
  RESULTS
  The obesity rate in adults born by cesarean delivery was 15.2% and in those born by vaginal delivery was 10.4% (P = 0.002). Adults born by cesarean delivery had an increased risk (prevalence ratio: 1.58; 95% CI: 1.23, 2.02) of obesity at adulthood after adjustments.
  
  
  CONCLUSIONS
  We hypothesize that increasing rates of cesarean delivery may play a role in the obesity epidemic worldwide.
authors.affiliation: Department of Pediatrics, Hospital de Clínicas de Porto Alegre, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Helena As
authors.initials: HA
authors.lastname: Goldani
authors.forename: Heloisa
authors.initials: H
authors.lastname: Bettiol
authors.forename: Marco A
authors.initials: MA
authors.lastname: Barbieri
authors.forename: Antonio Am
authors.initials: AA
authors.lastname: Silva
authors.forename: Marilyn
authors.initials: M
authors.lastname: Agranonik
authors.forename: Mauro B
authors.initials: MB
authors.lastname: Morais
authors.forename: Marcelo Z
authors.initials: MZ
authors.lastname: Goldani
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D002585:Cesarean Section / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012307:Risk Factors; D055815:Young Adult