Women with a previous caesarean delivery face a difficult choice in their next pregnancy: planning another caesarean or attempting vaginal delivery, both of which are associated with potential maternal and perinatal complications. This trial aimed to assess whether a multifaceted intervention, which promoted person-centred decision making and best practices, would reduce the risk of major perinatal morbidity among women with one previous caesarean delivery. We conducted an open, multicentre, cluster-randomised, controlled trial of a multifaceted 2-year intervention in 40 hospitals in Quebec among women with one previous caesarean delivery, in which hospitals were the units of randomisation and women the units of analysis. Randomisation was stratified according to level of care, using blocked randomisation. Hospitals were randomly assigned (1:1) to the intervention group (implementation of best practices and provision of tools that aimed to support decision making about mode of delivery, including an estimation of the probability of vaginal delivery and an ultrasound estimation of the risk of uterine rupture), or the control group (no intervention). The primary outcome was a composite risk of major perinatal morbidity. This trial was registered with ISRCTN, ISRCTN15346559. 21 281 eligible women delivered during the study period, from April 1, 2016 to Dec 13, 2019 (10 514 in the intervention group and 10 767 in the control group). None were lost to follow-up. There was a significant reduction in the rate of major perinatal morbidity from the baseline period to the intervention period in the intervention group as compared with the control group (adjusted odds ratio [OR] for incremental change over time, 0·72 [95% CI 0·52–0·99]; p=0·042; adjusted risk difference –1·2% [95% CI –2·0 to –0·1]). Major maternal morbidity was significantly reduced in the intervention group as compared with the control group (adjusted OR 0·54 [95% CI 0·33–0·89]; p=0·016). Minor perinatal and maternal morbidity, caesarean delivery, and uterine rupture rates did not differ significantly between groups. A multifaceted intervention supporting women in their choice of mode of delivery and promoting best practices resulted in a significant reduction in rates of major perinatal and maternal morbidity, without an increase in the rate of caesarean or uterine rupture. Canadian Institutes of Health Research (CIHR, MOP-142448).

中文翻译：

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既往剖腹产妇女的围产期发病率（PRISMA 试验）：整群随机试验

曾经进行过剖腹产的女性在下次怀孕时面临着艰难的选择：计划再次剖腹产还是尝试阴道分娩，这两者都可能导致潜在的孕产妇和围产期并发症。该试验旨在评估促进以人为本的决策和最佳实践的多方面干预措施是否会降低曾进行过剖腹产的妇女发生重大围产期发病的风险。我们在魁北克省的 40 家医院对曾经进行过剖腹产的妇女进行了一项开放、多中心、整群随机、对照试验，为期 2 年多方面进行干预，其中医院是随机分组单位，妇女是分析单位。使用分组随机化根据护理水平对随机化进行分层。医院被随机分配（1:1）到干预组（实施最佳实践并提供旨在支持分娩方式决策的工具，包括阴道分娩概率的估计和阴道分娩风险的超声估计）子宫破裂），或对照组（无干预）。主要结局是主要围产期发病率的复合风险。该试验已在 ISRCTN 注册，ISRCTN15346559。研究期间，即2016年4月1日至2019年12月13日，共有21 281名符合条件的妇女分娩（干预组为10 514人，对照组为10 767人）。没有人失访。与对照组相比，干预组从基线期到干预期的主要围产期发病率显着降低（随时间增量变化的调整比值比 [OR]，0·72 [95% CI 0·52–0·99]；p=0·042；调整后的风险差异 –1·2% [95% CI –2·0 至 –0·1]）。与对照组相比，干预组的主要孕产妇发病率显着降低（调整后 OR 0·54 [95% CI 0·33–0·89]；p=0·016）。轻微围产期和产妇发病率、剖腹产率和子宫破裂率在各组之间没有显着差异。支持妇女选择分娩方式并推广最佳做法的多方面干预措施显着降低了围产期和孕产妇的主要发病率，而剖腹产或子宫破裂的发生率没有增加。加拿大健康研究所（CIHR，MOP-142448）。