Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
Lunenfeld Tanenbaum Research Institute, Toronto, ON, Canada.
Acta Obstet Gynecol Scand. 2021 Feb;100(2):200-209. doi: 10.1111/aogs.14011. Epub 2020 Nov 6.
Pregnant women with a body mass index (BMI) ≥40 kg/m are at an increased risk of requiring planned- and unplanned cesarean deliveries (CD). The aim of this systematic review is to compare outcomes in women with BMI ≥ 40 kg/m based on planned and actual mode of birth.
Five databases were searched for English and French-language publications until February 2019, and all studies reporting on delivery outcomes in women with BMI ≥ 40 kg/m , stratified by planned and actual mode of birth, were included. Risk-of-bias was assessed using the Newcastle-Ottawa Scale. Relative risks (RR) and 95% confidence intervals were calculated using random-effects meta-analysis.
Ten observational studies were included. Anticipated vaginal birth vs planned CD (5 studies, n = 2216) was associated with higher risk for postpartum hemorrhage (13.0% vs 4.1%, P < .001, numbers needed to harm (NNH = 11), I = 0%) but lower risk for wound complications (7.6% vs 14.5%, P < .001, numbers needed to treat (NNT = 15), I = 58.3%). Planned trial of labor vs repeat CD (3 studies, n = 4144) was associated with higher risk for uterine dehiscence (0.94% vs 0.42%, P = .04, NNH = 200, I = 0%), endometritis (5.1% vs 2.2%, P < .001, NNH = 35, I = 0%), prolonged hospitalization (one study, 30.3% vs 26.0%, P = .003, NNH = 23), low five-minute Apgar scores (4.9% vs 1.7%, RR 2.95 (2.03, 4.28), NNH = 30, I = 0%) and birth trauma (1.1% vs 0.2%, P < .001, NNH = 111, I = 0%). Successful vaginal birth vs intrapartum CD (n = 3625) was associated with lower risk of postpartum hemorrhage (15.1% vs 70%, P < .001, NNT = 2, I = 0%), wound complications (one study, 0% vs 4.4%, P = .007, NNT = 23), prolonged hospitalization (one study, 1.9% vs 6.7%, 0.04, NNT = 21) and low five-minute Apgar scores (one study, 1.0% vs 5.6%, P = .03, NNT = 22), but more birth trauma (5.9% vs 0.6%, P = .005, NNH = 19, I = 0%). Compared groups had dissimilar demographic characteristics. Although studies scored 6-7/9 on risk-of-bias assessment, they were at high-risk for confounding by indication.
Evidence from observational studies suggests clinical equipoise regarding the optimal mode of delivery in women with BMI ≥ 40 kg/m and no prior CD. This question is best answered by a randomized trial. Based on an unplanned subgroup analysis, for women with BMI ≥ 40 kg/m and prior CD, repeat CD may be associated with better clinical outcomes.
身体质量指数（BMI）≥40 kg/m²的孕妇剖宫产的风险增加，包括计划性剖宫产和非计划性剖宫产。本系统综述的目的是比较 BMI≥40 kg/m²的孕妇根据计划分娩方式和实际分娩方式的结局。
检索了五个英文和法文数据库，检索截至 2019 年 2 月的文献，纳入了报告 BMI≥40 kg/m²的孕妇根据计划分娩方式和实际分娩方式分层的分娩结局的研究。使用纽卡斯尔-渥太华量表评估偏倚风险。使用随机效应荟萃分析计算相对风险（RR）和 95%置信区间。
纳入了 10 项观察性研究。预计阴道分娩与计划剖宫产（5 项研究，n=2216）相比，产后出血的风险更高（13.0% vs 4.1%，P<0.001，需要治疗的人数（NNT）为 11，I²=0%），但伤口并发症的风险较低（7.6% vs 14.5%，P<0.001，NNT 为 15，I²=58.3%）。计划性试产与重复剖宫产（3 项研究，n=4144）相比，子宫破裂的风险更高（0.94% vs 0.42%，P=0.04，NNH 为 200，I²=0%），子宫内膜炎的风险更高（5.1% vs 2.2%，P<0.001，NNH 为 35，I²=0%），住院时间延长（一项研究，30.3% vs 26.0%，P=0.003，NNH 为 23），5 分钟 Apgar 评分较低（4.9% vs 1.7%，RR 2.95（2.03，4.28），NNH 为 30，I²=0%）和分娩创伤（1.1% vs 0.2%，P<0.001，NNH 为 111，I²=0%）。阴道分娩成功与产时剖宫产（n=3625）相比，产后出血的风险较低（15.1% vs 70%，P<0.001，NNT 为 2，I²=0%），伤口并发症的风险较低（一项研究，0% vs 4.4%，P=0.007，NNT 为 23），住院时间延长（一项研究，1.9% vs 6.7%，P=0.04，NNT 为 21）和 5 分钟 Apgar 评分较低（一项研究，1.0% vs 5.6%，P=0.03，NNT 为 22），但分娩创伤的风险较高（5.9% vs 0.6%，P=0.005，NNH 为 19，I²=0%）。比较组具有不同的人口统计学特征。尽管研究的风险评估得分为 6-7/9，但它们存在明显的指示性偏倚风险。
来自观察性研究的证据表明，对于 BMI≥40 kg/m²且无既往剖宫产史的孕妇，哪种分娩方式最佳尚无定论。这个问题最好通过随机试验来回答。基于非计划性亚组分析，对于 BMI≥40 kg/m²且有既往剖宫产史的孕妇，重复剖宫产可能与更好的临床结局相关。
