title: Gestational weight gain, cesarean delivery, and cesarean delivery on maternal request: a cohort analysis of Chinese nulliparous women.
abstract: To examine the association between gestational weight gain (GWG) and cesarean delivery including cesarean delivery on maternal request (CDMR) among low-risk women.
  
  
  
  A total of 1,009,987 Chinese nulliparous women who delivered live term singletons during 1993-2010 were included. GWG, according to maternal pre-pregnancy body mass index-specified z-scores, was categorized into five groups: less than -1.2, -1.2 to less than -0.6, -0.6 to 0.6 (reference), more than 0.6 to 1.2, and more than 1.2. Multivariate log-binomial regression models were used to estimate the adjusted risk ratios and 95% confidence intervals (95% CIs).
  
  
  
  GWG was positively associated with overall cesarean and CDMR after adjusting for various confounders. Adjusted risk ratios for cesarean were 0.75 (95% CI, 0.73-0.77), 0.84 (95% CI, 0.82-0.85), 1.00, 1.16 (95% CI, 1.14-1.19), and 1.32 (95% CI, 1.29-1.35) in five ascending GWG categories, and 0.70 (95% CI, 0.67-0.73), 0.80 (95% CI, 0.78-0.82), 1.00, 1.20 (95% CI, 1.18-1.23), and 1.43 (95% CI, 1.40-1.45) for CDMR. The graded positive associations were consistent across levels of maternal pre-pregnancy body mass index, and in strata defined by southern and/or northern provinces, urban and/or rural residence, maternal age at delivery, year of delivery, and level of delivering hospital.
  
  
  
  Even among low-risk women, higher GWG was monotonically associated with an increased risk of cesarean delivery, indicating that limiting GWG could benefit to curb the rate of both medically necessary and unnecessary cesareans.
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China; Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China.
authors.forename: Yubo B
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Hongtian T
authors.initials: HT
authors.lastname: Li
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Rongwei W
authors.initials: RW
authors.lastname: Ye
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Zhiwen W
authors.initials: ZW
authors.lastname: Li
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Yali L
authors.initials: YL
authors.lastname: Zhang
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
authors.forename: Aiguo G
authors.initials: AG
authors.lastname: Ren
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China; Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China. Electronic address: liujm@pku.edu.cn.
authors.forename: JianMeng M
authors.initials: JM
authors.lastname: Liu
mesh_terms: D000328:Adult; D044466:Asian People / Q000706:statistics & numerical data*; D002585:Cesarean Section / Q000706:statistics & numerical data* / Q000639:trends*; D002681:China; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D013533:Gestational Carriers / Q000706:statistics & numerical data*; D015430:Weight Gain
keywords: Cesarean delivery; Cesarean delivery on maternal request; Chinese women; Gestational weight gain