Lisonkova Sarka, Muraca Giulia M, Potts Jayson, Liauw Jessica, Chan Wee-Shian, Skoll Amanda, Lim Kenneth I
Department of Obstetrics and Gynaecology, University of British Columbia and the Children's and Women's Hospital and Health Centre of British Columbia, Vancouver, Canada.
School of Population and Public Health, University of British Columbia, Vancouver, Canada.
JAMA. 2017 Nov 14;318(18):1777-1786. doi: 10.1001/jama.2017.16191.
Although high body mass index (BMI) is associated with adverse birth outcomes, the association with severe maternal morbidity is unclear.
To examine the association between prepregnancy BMI and severe maternal morbidity.
DESIGN, SETTING, AND PARTICIPANTS: Retrospective population-based cohort study including all singleton hospital births in Washington State, 2004-2013. Demographic data and morbidity diagnoses were obtained from linked birth certificates and hospitalization files.
Prepregnancy BMI (weight in kilograms divided by height in meters squared) categories included underweight (<18.5), normal BMI (18.5-24.9), overweight (25.0-29.9), obesity class 1 (30.0-34.9), obesity class 2 (35.0-39.9), and obesity class 3 (≥40).
Composite severe maternal morbidity or mortality included life-threatening conditions and conditions leading to serious sequelae (eg, amniotic fluid embolism, hysterectomy), complications requiring intensive care unit admission, and maternal death. Logistic regression was used to obtain adjusted odds ratios (ORs) and adjusted rate differences with 95% confidence intervals, adjusted for confounders (eg, maternal age and parity).
Overall, 743 630 women were included in the study (mean age, 28.1 [SD, 6.0] years; 41.4% nulliparous). Prepregnancy BMI was distributed as follows: underweight, 3.2%; normal weight, 47.5%; overweight, 25.8%; obesity class 1, 13.1%; obesity class 2, 6.2%; and obesity class 3, 4.2%. Rates of severe maternal morbidity or mortality were 171.5, 143.2, 160.4, 167.9, 178.3 and 202.9 per 10 000 women, respectively. Adjusted ORs were 1.2 (95% CI, 1.0-1.3) for underweight women; 1.1 (95% CI, 1.1-1.2) for overweight women; 1.1 (95% CI, 1.1-1.2) for women with class 1 obesity; 1.2 (95% CI, 1.1-1.3) for women with class 2 obesity; and 1.4 (95% CI, 1.3-1.5) for women with class 3 obesity compared with women with normal BMI. Absolute risk increases (adjusted rate differences per 10 000 women, compared with women with normal BMI) were 28.8 (95% CI, 12.2-47.2) for underweight women, 17.6 (95% CI, 10.5-25.1) for overweight women, 24.9 (95% CI, 15.7-34.6) for women with class 1 obesity, 35.8 (95% CI, 23.1-49.5) for women with class 2 obesity, and 61.1 (95% CI, 44.8-78.9) for women with class 3 obesity.
Among pregnant women in Washington State, low and high prepregnancy BMI, compared with normal BMI, were associated with a statistically significant but small absolute increase in severe maternal morbidity or mortality.
尽管高体重指数（BMI）与不良出生结局相关，但与严重孕产妇发病的关联尚不清楚。
研究孕前BMI与严重孕产妇发病之间的关联。
设计、地点和参与者：基于人群的回顾性队列研究，纳入2004 - 2013年华盛顿州所有单胎医院分娩病例。人口统计学数据和发病诊断信息来自关联的出生证明和住院档案。
孕前BMI（体重千克数除以身高米数的平方）分类包括体重过轻（<18.5）、正常BMI（18.5 - 24.9）、超重（25.0 - 29.9）、1级肥胖（30.0 - 34.9）、2级肥胖（35.0 - 39.9）和3级肥胖（≥40）。
综合严重孕产妇发病或死亡包括危及生命的情况和导致严重后遗症的情况（如羊水栓塞、子宫切除术）、需要入住重症监护病房的并发症以及孕产妇死亡。采用逻辑回归分析以获得调整后的比值比（OR）和调整后的率差，并给出95%置信区间，同时对混杂因素（如产妇年龄和产次）进行了调整。
总体而言，该研究纳入了743630名女性（平均年龄28.1[标准差6.0]岁；41.4%为初产妇）。孕前BMI分布如下：体重过轻占3.2%；正常体重占47.5%；超重占25.8%；1级肥胖占13.1%；2级肥胖占6.2%；3级肥胖占4.2%。严重孕产妇发病或死亡率分别为每10000名女性171.5、143.2、160.4、167.9、178.3和202.9例。与BMI正常的女性相比，体重过轻女性的调整后OR为1.2（95%置信区间，1.0 - 1.3）；超重女性为1.1（95%置信区间，1.1 - 1.2）；1级肥胖女性为1.1（95%置信区间，1.1 - 1.2）；2级肥胖女性为1.2（95%置信区间，1.1 - 1.3）；3级肥胖女性为1.4（95%置信区间，1.3 - 1.5）。与BMI正常的女性相比，绝对风险增加（每万名女性的调整后率差）体重过轻女性为28.8（95%置信区间，12.2 - 47.2），超重女性为17.6（95%置信区间，10.5 - 25.1），1级肥胖女性为24.9（95%置信区间，15.7 - 34.6），2级肥胖女性为35.8（95%置信区间，23.1 - 49.
