Université Paris Cité, INSERM U1153, Obstetrical, Perinatal and Pediatric Epidemiology (EPOPé) Research Team, Center for Research in Epidemiology and Statistics (CRESS), Paris, France.
Department of Obstetrics and Gynecology, Charles Nicolle University Hospital, Rouen, France.
Int J Gynaecol Obstet. 2024 Feb;164(2):732-740. doi: 10.1002/ijgo.15043. Epub 2023 Aug 11.
To explore the association between induction of labor (IOL) and postpartum hemorrhage (PPH) after vaginal delivery.
We included women from the merged database of three randomized prospective trials (TRACOR, CYTOCINON, and TRAAP) that measured postpartum blood loss precisely, with standardized methods. IOL was considered overall and according to its method. The association between IOL and PPH was tested by multivariate logistic regression modeling, adjusted for confounders, and by propensity score matching. The role of potential intermediate factors, i.e. estimated quantity of oxytocin administered during labor and operative vaginal delivery, was assessed with structural equation modeling.
Labor was induced for 1809 of the 9209 (19.6%) women. IOL was associated with a significantly higher risk of PPH of 500 mL or more (adjusted odds ratio 1.56, 95% confidence interval 1.42-1.70) and PPH of 1000 mL or more (adjusted odds ratio 1.51, 95% confidence interval 1.16-1.96). The risk of PPH increased similarly regardless of the method of induction. The results were similar after propensity score matching (odds ratio for PPH ≥500 mL 1.57, 95% confidence interval 1.33-1.87, odds ratio for PPH ≥1000 mL 1.57, 95% confidence interval 1.06-2.07). Structural equation modeling showed that 34% of this association was mediated by the quantity of oxytocin administered during labor and 1.3% by women who underwent operative vaginal delivery.
Among women with vaginal delivery, the risk of PPH is higher in those with IOL, regardless of its method, and after accounting for indication bias. The quantity of oxytocin administered during labor may explain one third of this association.
探讨阴道分娩时引产（IOL）与产后出血（PPH）的关系。
我们纳入了三项前瞻性随机对照试验（TRACOR、CYTOCINON 和 TRAAP）的合并数据库中的女性，这些试验精确测量了产后出血量，并采用了标准化方法。我们综合考虑了所有情况下的 IOL 和根据其方法进行的 IOL，并通过多变量逻辑回归模型、混杂因素调整和倾向评分匹配来检验 IOL 与 PPH 之间的关联。我们还通过结构方程模型评估了潜在中间因素（即分娩期间给予的催产素估计量和经阴道助产）的作用。
9209 名女性中，1809 名（19.6%）接受了引产。IOL 与 PPH 500ml 或以上（校正比值比 1.56，95%置信区间 1.42-1.70）和 PPH 1000ml 或以上（校正比值比 1.51，95%置信区间 1.16-1.96）的风险显著增加相关。无论引产方法如何，PPH 的风险增加情况相似。倾向评分匹配后结果相似（PPH≥500ml 的比值比为 1.57，95%置信区间 1.33-1.87，PPH≥1000ml 的比值比为 1.57，95%置信区间 1.06-2.07）。结构方程模型显示，分娩期间给予的催产素量解释了这种关联的 34%，经阴道助产解释了 1.3%。
在阴道分娩的女性中，IOL 组的 PPH 风险高于非 IOL 组，无论其方法如何，并且在考虑了适应症偏倚后也是如此。分娩期间给予的催产素量可能解释了这种关联的三分之一。
