Zhou Yubo B, Li Hongtian T, Ye Rongwei W, Li Zhiwen W, Zhang Yali L, Zhang Le, Ren Aiguo G, Liu JianMeng M
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.
Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University Health Science Center, Beijing, China.
Ann Epidemiol. 2017 Feb;27(2):96-102.e3. doi: 10.1016/j.annepidem.2016.11.014. Epub 2016 Dec 9.
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.
研究低风险女性孕期体重增加（GWG）与剖宫产包括产妇要求剖宫产（CDMR）之间的关联。
纳入1993年至2010年期间分娩足月单胎的1,009,987名中国初产妇。根据孕前体重指数指定的z分数，将GWG分为五组：小于-1.2、-1.2至小于-0.6、-0.6至0.6（参照组）、大于0.6至1.2以及大于1.2。使用多变量对数二项回归模型来估计调整后的风险比和95%置信区间（95%CI）。
在调整各种混杂因素后，GWG与总体剖宫产及CDMR呈正相关。五个GWG递增类别中剖宫产的调整后风险比分别为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）和1.32（95%CI，1.29 - 1.35），CDMR的调整后风险比分别为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）和1.43（95%CI，1.40 - 1.45）。这种分级正相关在孕前体重指数水平、按南方和/或北方省份、城市和/或农村居住地、分娩时产妇年龄、分娩年份以及分娩医院级别划分的亚组中均一致。
即使在低风险女性中，较高的GWG也与剖宫产风险增加呈单调关联，这表明限制GWG可能有助于控制必要和不必要剖宫产的发生率。
