title: Maternal obesity, environmental factors, cesarean delivery and breastfeeding as determinants of overweight and obesity in children: results from a cohort.
abstract: BACKGROUND
  Overweight and obesity are a public health problem with a multifactorial aetiology. The objective of this study was to evaluate risk factors for overweight and obesity in children at 6 years of age, including type of delivery and breastfeeding.
  
  
  METHODS
  This study relates to a cohort of 672 mother-baby pairs who have been followed from birth up to 6 years of age. The sample included mothers and infants seen at all ten maternity units in a large Brazilian city. Genetic, socioeconomic, demographic variables and postnatal characteristics were analyzed. The outcome analyzed was overweight and/or obesity defined as a body mass index greater than or equal to +1 z-score. The sample was stratified by breastfeeding duration, and a descriptive analysis was performed using a hierarchical logistic regression. P-values of <0.05 were considered significant.
  
  
  RESULTS
  Prevalence rates (PR) of overweight and obesity among the children were 15.6% and 12.9%, respectively. Among the subset of breastfed children, factors associated with the outcome were maternal overweight and/or obesity (PR 1.92; 95% confidence interval "95% CI" 1.15-3.24) and lower income (PR 0.50; 95% CI 0.29-0.85). Among children who had not been breastfed or had been breastfed for shorter periods (less than 12 months), predictors were mothers with lower levels of education (PR 0.39; 95% CI 0.19-0.78), working mothers (PR 1.83; 95% CI 1.05-3.21), caesarean delivery (PR 1.98; 95% CI 1.14 - 3.50) and maternal obesity (PR 3.05; 95% CI 1.81 - 5.25).
  
  
  CONCLUSIONS
  Maternal obesity and caesarean delivery were strongly associated with childhood overweight and/or obesity. Lower family income and lower levels of education were identified as protective factors. Breastfeeding duration appeared to modify the association between overweight/obesity and the other predictors studied.
authors.affiliation: Federal University of Recôncavo da Bahia, CEP 44.570-000, Santo Antônio de Jesus, Bahia, Brazil. euportela@yahoo.com.br.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Portela
authors.affiliation: State University of Feira de Santana, Feira de Santana, Bahia, Brazil. tatianaovieira@gmail.com.
authors.forename: Tatiana O
authors.initials: TO
authors.lastname: Vieira
authors.affiliation: Federal University of Bahia, Salvador, Bahia, Brazil. sheilaalvim@hotmail.com.
authors.forename: Sheila Ma
authors.initials: SM
authors.lastname: Matos
authors.affiliation: State University of Feira de Santana, Feira de Santana, Bahia, Brazil. noliveir2003@hotmail.com.
authors.forename: Nelson F
authors.initials: NF
authors.lastname: de Oliveira
authors.affiliation: State University of Feira de Santana, Feira de Santana, Bahia, Brazil. gracieteovieira@gmail.com.
authors.forename: Graciete O
authors.initials: GO
authors.lastname: Vieira
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D001942:Breast Feeding / Q000706:statistics & numerical data*; D002585:Cesarean Section / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data; D004522:Educational Status; D004777:Environment; D005260:Female; D005865:Gestational Age; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009035:Mothers / Q000706:statistics & numerical data*; D009043:Motor Activity; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology; D063766:Pediatric Obesity / Q000453:epidemiology*; D011203:Poverty; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D065840:Protective Factors; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult