title: Breast-feeding in relation to weight retention up to 36 months postpartum in the Norwegian Mother and Child Cohort Study: modification by socio-economic status?
abstract: OBJECTIVE
  We investigated the association between full breast-feeding up to 6 months as well as partial breast-feeding after 6 months and maternal weight retention at 6, 18 and 36 months after delivery in the Norwegian Mother and Child Cohort Study (MoBa), conducted by the Norwegian Institute of Public Health.
  
  
  METHODS
  Cohort study. Information on exposure and outcome was collected by questionnaire.
  
  
  METHODS
  Norway.
  
  
  METHODS
  Women at 6 months (n 49 676), 18 months (n 27 187) and 36 months (n 17 343) postpartum.
  
  
  RESULTS
  Longer duration of full breast-feeding as well as partial breast-feeding was significantly related to lower weight retention at 6 months. At 18 months full breast-feeding (0-6 months) and partial breast-feeding for 12-18 months were significantly related to lower weight retention. At 36 months only full breast-feeding (0-6 months) was significantly related to lower weight retention. For each additional month of full breast-feeding, maternal weight was lowered by 0·50 kg/month at 6 months, 0·10 kg/month at 18 months and 0·14 kg/month at 36 months (adjusted for pre-pregnant BMI, pregnancy weight gain, age and parity). Partial breast-feeding resulted in 0·25 kg/month lower maternal weight at 6 months. Interactions were found between household income and full breast-feeding in relation to weight retention at 6, 18 and 36 months, indicating most benefit among women with low income.
  
  
  CONCLUSIONS
  The present study supports the hypothesis that full breast-feeding contributes to lower postpartum weight retention and shows that the effect is maintained for as long as 3 years postpartum.
authors.affiliation: 1Department of Internal Medicine and Clinical Nutrition,Sahlgrenska Academy,University of Gothenburg,PO Box 459,SE-405 30 Göteborg,Gothenburg,Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Brandhagen
authors.affiliation: 2Department of Public Health and Community Medicine,Sahlgrenska Academy,University of Gothenburg,Gothenburg,Sweden.
authors.forename: Lauren
authors.initials: L
authors.lastname: Lissner
authors.affiliation: 3Division of Environmental Medicine,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: Anne Lise
authors.initials: AL
authors.lastname: Brantsaeter
authors.affiliation: 3Division of Environmental Medicine,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: Helle Margrete
authors.initials: HM
authors.lastname: Meltzer
authors.affiliation: 4Norwegian Resource Centre for Breastfeeding,Women and Children's Division,Oslo University Hospital,Oslo,Norway.
authors.forename: Anna-Pia
authors.initials: AP
authors.lastname: Häggkvist
authors.affiliation: 3Division of Environmental Medicine,Norwegian Institute of Public Health,Oslo,Norway.
authors.forename: Margaretha
authors.initials: M
authors.lastname: Haugen
authors.affiliation: 1Department of Internal Medicine and Clinical Nutrition,Sahlgrenska Academy,University of Gothenburg,PO Box 459,SE-405 30 Göteborg,Gothenburg,Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Winkvist
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001942:Breast Feeding; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007182:Income; D007223:Infant; D007231:Infant, Newborn; D009035:Mothers; D009664:Norway; D009765:Obesity / Q000517:prevention & control*; D049590:Postpartum Period; D011203:Poverty; D011247:Pregnancy; D012923:Social Class; D015430:Weight Gain
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