Alexander Robin, Bhaskar Swetha, Azcoaga-Lorenzo Amaya, Fagbamigbe Adeniyi Francis, Chow Clarine Y C, Kuan Kevin K W, Stock Sarah J, Unger Stefan A, Swallow Ben, McCowan Colin, Unger Holger W
Research Fellow in Medical Statistics, Division of Population and Behavioural Sciences, School of Medicine, University of St Andrews, St Andrews, United Kingdom.
Consultant Obstetrician and Gynaecologist, Victoria Hospital, Kirkcaldy, United Kingdom.
PLoS One. 2025 Jul 21;20(7):e0326001. doi: 10.1371/journal.pone.0326001. eCollection 2025.
The effects of mode of birth for women in preterm breech labour could not be successfully determined in randomised trials. We aimed to explore the effect of caesarean birth on perinatal mortality for women in spontaneous-onset preterm labour with a singleton baby presenting breech through target trial emulation.
A target trial emulation of a parallel group randomised controlled trial using routinely collected Scottish electronic health record data was performed. Participants were pregnant women at 24-36 gestational weeks with a singleton breech baby, no prior caesarean birth, in spontaneous labour with a live baby at labour onset (1 January 1997 to 31 December 2019). We compared caesarean birth (intervention) to vaginal breech birth (control) in a per-protocol analysis (actual mode of birth). The primary outcome was extended perinatal mortality (intrapartum stillbirths and neonatal deaths). A multiple logistic regression model with inverse probability weight was used to adjust for measured confounders. There were 2,092 caesarean births and 967 vaginal breech births. In the emulated trial, caesarean birth reduced extended perinatal mortality compared to vaginal breech birth (odds ratio [OR] 0.35, 95% confidence interval [CI] 0.27 to 0.43). At 24 weeks' gestation, caesarean birth decreased the odds of perinatal death by 47.7% (OR: 0.53, 95% CI: 0.35 to 0.78). At 36 gestational weeks it was associated with an 82.1% reduction in the odds of perinatal death (OR: 0.18, 95% CI: 0.10 to 0.32). As the risk of perinatal mortality is inversely correlated with gestational age at birth, seven and 88 caesarean births were needed to prevent one perinatal death at 24 weeks and 36 weeks' gestation, respectively.
Caesarean birth was associated with a reduced risk of extended perinatal mortality in spontaneous preterm singleton breech labour in a per-protocol trial emulation. Observational data that accurately captures planned mode of birth and unmeasured confounders such as breech subtype is required to emulate an intention-to-treat analysis.
随机试验未能成功确定早产臀位分娩方式对女性的影响。我们旨在通过目标试验模拟，探讨剖宫产对单胎臀位自发早产女性围产期死亡率的影响。
使用常规收集的苏格兰电子健康记录数据，对平行组随机对照试验进行目标试验模拟。参与者为妊娠24 - 36周的孕妇，单胎臀位，无既往剖宫产史，自发临产且临产时胎儿存活（1997年1月1日至2019年12月31日）。在符合方案分析（实际分娩方式）中，我们将剖宫产（干预）与臀位阴道分娩（对照）进行比较。主要结局是延长围产期死亡率（产时死产和新生儿死亡）。使用带逆概率权重的多元逻辑回归模型对测量的混杂因素进行调整。有2092例剖宫产和967例臀位阴道分娩。在模拟试验中，与臀位阴道分娩相比，剖宫产降低了延长围产期死亡率（比值比[OR] 0.35，95%置信区间[CI] 0.27至0.43）。在妊娠24周时，剖宫产使围产期死亡几率降低47.7%（OR：0.53，95% CI：0.35至0.78）。在妊娠36周时，它与围产期死亡几率降低82.1%相关（OR：0.18，95% CI：0.10至0.32）。由于围产期死亡率风险与出生时的孕周呈负相关，在妊娠24周和36周时，分别需要7例和88例剖宫产来预防1例围产期死亡。
在符合方案试验模拟中，剖宫产与自发早产单胎臀位分娩时延长围产期死亡率风险降低相关。需要准确捕捉计划分娩方式和未测量混杂因素（如臀位亚型）的观察性数据来模拟意向性分析。
