Abstract：
OBJECTIVE: This study aimed (1) to assess the association between the length of the third stage of labor and adverse maternal outcome after vaginal birth and (2) to evaluate whether earlier manual placenta removal reduces the risk of adverse outcome.
METHODS: PubMed, MEDLINE, Embase, ClinicalTrials.gov, the Cochrane Library, Journals@Ovid, and the World Health Organization International Clinical Trials Registry were searched from January 1, 2000, to June 13, 2023.
METHODS: All studies that assessed adverse maternal outcome, defined as any maternal complication after vaginal birth, concerning the length of the third stage of labor and the timing of manual placenta removal were included.
METHODS: The included studies were evaluated using the Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology methodology. Pooled odds ratios with 95% confidence intervals were calculated. Heterogeneity (I2 test) was assessed, subgroup analyses were performed, and 95% prediction intervals were calculated.
RESULTS: To meet the first objective, 18 cohort studies were included. The assessed cutoff values for the length of the third stage of labor were 15, 30, and 60 minutes. Women with a third stage of labor of ≥15 minutes had an increased risk of postpartum hemorrhage compared with those with a third stage of labor of <15 minutes (odds ratio, 5.55; 95% confidence interval, 1.74-17.72). For women without risk factors for postpartum hemorrhage, the odds ratio was 2.20 (95% confidence interval, 0.75-6.49). Among women with a third stage of labor of ≥60 minutes vs women with a third stage of labor of <60 minutes, the odds ratio was 3.72 (95% confidence interval, 2.36-5.89). The incidence of red blood cell transfusion was higher for a third stage of labor of ≥30 minutes than for a third stage of labor of <30 minutes (odds ratio, 3.23; 95% confidence interval, 2.26-4.61). Of note, 3 studies assessed the timing of placenta removal and the risk of adverse maternal outcome. However, the results could not be pooled because of the different outcome measures. Moreover, 1 randomized controlled trial (RCT) reported a significantly higher incidence of hemodynamic compromise in women with manual placenta removal at 15 minutes than in women with manual placenta removal at 10 minutes (30/156 [19.2%] vs 10/156 [6.4%], respectively), whereas 2 observational studies reported a lower risk of bleeding among women without manual placenta removal.
CONCLUSIONS: Although the risk of adverse maternal outcome after vaginal birth increases when the third stage of labor exceeds 15 minutes, there is no convincing supporting evidence that reducing the length of the third stage of labor by earlier manual removal of the placenta can reduce the incidence of adverse maternal outcome.
METHODS: PubMed, MEDLINE, Embase, ClinicalTrials.gov, the Cochrane Library, Journals@Ovid, and the World Health Organization International Clinical Trials Registry were searched from January 1, 2000, to June 13, 2023.
METHODS: All studies that assessed adverse maternal outcome, defined as any maternal complication after vaginal birth, concerning the length of the third stage of labor and the timing of manual placenta removal were included.
METHODS: The included studies were evaluated using the Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology methodology. Pooled odds ratios with 95% confidence intervals were calculated. Heterogeneity (I2 test) was assessed, subgroup analyses were performed, and 95% prediction intervals were calculated.
RESULTS: To meet the first objective, 18 cohort studies were included. The assessed cutoff values for the length of the third stage of labor were 15, 30, and 60 minutes. Women with a third stage of labor of ≥15 minutes had an increased risk of postpartum hemorrhage compared with those with a third stage of labor of <15 minutes (odds ratio, 5.55; 95% confidence interval, 1.74-17.72). For women without risk factors for postpartum hemorrhage, the odds ratio was 2.20 (95% confidence interval, 0.75-6.49). Among women with a third stage of labor of ≥60 minutes vs women with a third stage of labor of <60 minutes, the odds ratio was 3.72 (95% confidence interval, 2.36-5.89). The incidence of red blood cell transfusion was higher for a third stage of labor of ≥30 minutes than for a third stage of labor of <30 minutes (odds ratio, 3.23; 95% confidence interval, 2.26-4.61). Of note, 3 studies assessed the timing of placenta removal and the risk of adverse maternal outcome. However, the results could not be pooled because of the different outcome measures. Moreover, 1 randomized controlled trial (RCT) reported a significantly higher incidence of hemodynamic compromise in women with manual placenta removal at 15 minutes than in women with manual placenta removal at 10 minutes (30/156 [19.2%] vs 10/156 [6.4%], respectively), whereas 2 observational studies reported a lower risk of bleeding among women without manual placenta removal.
CONCLUSIONS: Although the risk of adverse maternal outcome after vaginal birth increases when the third stage of labor exceeds 15 minutes, there is no convincing supporting evidence that reducing the length of the third stage of labor by earlier manual removal of the placenta can reduce the incidence of adverse maternal outcome.
摘要：
目的：（1）评估第三产程的持续时间与阴道分娩后不良产妇结局之间的关系，以及（2）评估早期手动去除胎盘是否降低了不良结局的风险。
方法：PubMed/MEDLINE，EMBASE,ClinicalTrials.gov,科克伦图书馆,2000年1月1日至2023年6月13日的期刊@Ovid和WHO国际临床试验注册。
方法：所有评估不良母婴结局的研究，定义为阴道分娩后的任何产妇并发症，与第三产程的持续时间和人工胎盘去除的时间有关。
方法：根据COSMOS-E（进行病因观察性研究的系统评价和荟萃分析）方法对纳入的研究进行评估。计算具有95%置信区间的集合比值比。我们评估了异质性（I2检验）；进行了亚组分析；并计算了95％的预测间隔。
结果：要回答第一个目标，纳入18项队列研究。第三阶段的评估截止时间为：15、30和60分钟。与<15分钟相比，第三阶段≥15分钟的妇女产后出血风险增加（几率[OR]5.55;95CI1.74,17.72）。对于没有产后出血危险因素的妇女，OR为2.20；95CI0.75,6.49。在第三阶段≥60分钟与<60分钟的女性中，OR为3.72；95CI2.36-5.89。第三阶段≥30分钟与<30分钟相比，红细胞输注的发生率增加（OR3.23;95CI2.26-4.61）。三项研究评估了胎盘切除的时机和不良母体结局的风险，但由于结局指标不同，无法汇总。一项随机对照试验报道，15分钟时手动去除胎盘的女性血液动力学受损的发生率明显高于10分钟（19.2%，30/1566.4%，10/156），而两项观察性研究报告未进行手动胎盘摘除的女性出血风险较低。
结论：尽管当第三产程超过15分钟时，阴道分娩后不良产妇结局的风险增加，没有令人信服的证据支持通过早期人工切除胎盘以减少不良产妇结局的发生率来减少第三产程.
方法：PubMed/MEDLINE，EMBASE,ClinicalTrials.gov,科克伦图书馆,2000年1月1日至2023年6月13日的期刊@Ovid和WHO国际临床试验注册。
方法：所有评估不良母婴结局的研究，定义为阴道分娩后的任何产妇并发症，与第三产程的持续时间和人工胎盘去除的时间有关。
方法：根据COSMOS-E（进行病因观察性研究的系统评价和荟萃分析）方法对纳入的研究进行评估。计算具有95%置信区间的集合比值比。我们评估了异质性（I2检验）；进行了亚组分析；并计算了95％的预测间隔。
结果：要回答第一个目标，纳入18项队列研究。第三阶段的评估截止时间为：15、30和60分钟。与<15分钟相比，第三阶段≥15分钟的妇女产后出血风险增加（几率[OR]5.55;95CI1.74,17.72）。对于没有产后出血危险因素的妇女，OR为2.20；95CI0.75,6.49。在第三阶段≥60分钟与<60分钟的女性中，OR为3.72；95CI2.36-5.89。第三阶段≥30分钟与<30分钟相比，红细胞输注的发生率增加（OR3.23;95CI2.26-4.61）。三项研究评估了胎盘切除的时机和不良母体结局的风险，但由于结局指标不同，无法汇总。一项随机对照试验报道，15分钟时手动去除胎盘的女性血液动力学受损的发生率明显高于10分钟（19.2%，30/1566.4%，10/156），而两项观察性研究报告未进行手动胎盘摘除的女性出血风险较低。
结论：尽管当第三产程超过15分钟时，阴道分娩后不良产妇结局的风险增加，没有令人信服的证据支持通过早期人工切除胎盘以减少不良产妇结局的发生率来减少第三产程.
