title: Greater early and mid-pregnancy gestational weight gains are associated with excess adiposity in mid-childhood.
abstract: It is unclear how specific periods of gestational weight gain (GWG) during pregnancy relate to childhood adiposity. The goal of this study was to assess the differential impact of GWG timing on childhood body composition.
  
  
  
  In 979 mother-child pairs from the pre-birth Project Viva cohort, trimester-specific GWG was calculated using clinically recorded weights. Outcomes included body mass index (BMI) z-score, dual X-ray absorptiometry fat mass index (kg/m(2) ), and fat-free mass index (kg/m(2) ) in mid-childhood. Linear regression models were used to assess associations of each trimester's GWG (per 0.2 kg/week) with childhood outcomes, adjusted for maternal prepregnancy BMI, sociodemographic variables, lifestyle, and GWG in prior trimester(s).
  
  
  
  Mean (SD) first trimester GWG was 0.22 (0.22) kg/week, second trimester 0.49 (0.18) kg/week, and third trimester 0.47 (0.20) kg/week. Faster first trimester GWG was associated with higher BMI z-score (0.06 units [95% CI: 0.01-0.12] per 0.2 kg/week) and with higher adiposity according to all indices; associations were strongest in women with prepregnancy BMI >30 kg/m(2) . Faster second trimester GWG was associated with higher BMI z-score (0.11 [0.04-0.18]), fat mass (fat mass index = 0.16 [0.02-0.31] kg/m(2) ), and lean mass (fat-free mass index = 0.11 [0.01-0.22] kg/m(2) ). Third trimester GWG was not associated with childhood adiposity.
  
  
  
  These results reinforce the importance of addressing appropriate GWG in early pregnancy.
authors.affiliation: Department of Population Medicine, Obesity Prevention Program, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.|Diabetes Unit, Massachusetts General Hospital, Boston, Massachusetts, USA.|Department of Medicine, Université de Sherbrooke, Sherbrooke, Canada.
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Hivert
authors.affiliation: Department of Population Medicine, Obesity Prevention Program, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Rifas-Shiman
authors.affiliation: Department of Population Medicine, Obesity Prevention Program, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gillman
authors.affiliation: Department of Population Medicine, Obesity Prevention Program, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Oken
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity; D000328:Adult; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D011247:Pregnancy; D011264:Pregnancy Trimesters / Q000502:physiology*; D011446:Prospective Studies; D013997:Time Factors; D015430:Weight Gain