title: Pre-pregnancy BMI, gestational weight gain and postpartum weight retention: a meta-analysis of observational studies.
abstract: OBJECTIVE
  To determine the association of gestational weight gain (GWG) or pre-pregnancy BMI with postpartum weight retention (PPWR).
  
  
  METHODS
  Meta-analysis.
  
  
  METHODS
  PubMed, Cochrane Controlled Trials Register, EMBASE, Science Citation Index Expanded, Current Contents Connects and Biosis Previews were used to search articles.
  
  
  METHODS
  Publications that described the influence of pre-pregnancy BMI or GWG on PPWR.
  
  
  RESULTS
  Seventeen studies that satisfied the eligibility criteria were included in the analyses. Women with inadequate and excessive GWG had significantly lower mean PPWR of -2·14 kg (95 % CI -2·43, -1·85 kg) and higher PPWR of 3·21 kg (95 % CI 2·79, 3·62 kg), respectively, than women with adequate GWG. When postpartum time spans were stratified into 1-3 months, 3-6 months, 6-12 months, 12-36 months and ≥15 years, the association between inadequate GWG and PPWR faded over time and became insignificant (-1·42 kg; 95 % CI -3·08, 0·24 kg) after ≥15 years. However, PPWR in women with excess GWG exhibited a U-shaped trend; that is, a decline during the early postpartum time span (year 1) and then an increase in the following period. Meta-analysis of qualitative studies showed a significant relationship between excessive GWG and higher PPWR risk (OR=2·08; 95 % CI 1·60, 2·70). Moreover, meta-analysis of pre-pregnancy BMI on PPWR indicated that mean PPWR decreased with increasing BMI group.
  
  
  CONCLUSIONS
  These findings suggest that GWG, rather than pre-pregnancy BMI, determines the shorter- or longer-term PPWR.
authors.affiliation: 1Department of Orthopedics,Minhang Hospital,Fudan University,Shanghai,People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Rong
authors.affiliation: 2Nestlé Research Center,Beijing,People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yu
authors.affiliation: 3China Astronaut Research and Training Center,Department of Space Food and Nutrition,Beijing,People's Republic of China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Han
authors.affiliation: 2Nestlé Research Center,Beijing,People's Republic of China.
authors.forename: Ignatius M Y
authors.initials: IM
authors.lastname: Szeto
authors.affiliation: 4School of Public Health,Peking University Health Science Center,38 Xueyuan Road,Haidian District,Beijing 100191,People's Republic of China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Qin
authors.affiliation: 2Nestlé Research Center,Beijing,People's Republic of China.
authors.forename: Junkuan
authors.initials: J
authors.lastname: Wang
authors.affiliation: 2Nestlé Research Center,Beijing,People's Republic of China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Ning
authors.affiliation: 4School of Public Health,Peking University Health Science Center,38 Xueyuan Road,Haidian District,Beijing 100191,People's Republic of China.
authors.forename: Peiyu
authors.initials: P
authors.lastname: Wang
authors.affiliation: 4School of Public Health,Peking University Health Science Center,38 Xueyuan Road,Haidian District,Beijing 100191,People's Republic of China.
authors.forename: Defu
authors.initials: D
authors.lastname: Ma
mesh_terms: D015992:Body Mass Index; D016208:Databases, Factual; D004032:Diet; D005260:Female; D006801:Humans; D009043:Motor Activity; D064887:Observational Studies as Topic; D049590:Postpartum Period; D011247:Pregnancy; D014481:United States; D015430:Weight Gain
keywords: BMI; Gestational weight gain; Postpartum weight retention