[Retrospective analysis of associated factors and adverse pregnancy outcomes of postpartum hemorrhage in the caesarean section of different types of placenta previa].

Objective: To analyze associated factors and adverse pregnancy outcomes of postpartum hemorrhage in the caesarean section of puerperae with different types of placenta previa. Methods: This retrospective research was a case-control study. Puerperae with cesarean section of placenta previa from January 2019 to December 2020 in Women's Hospital, School of Medicine, Zhejiang University were collected and divided into the<1 000 ml control group or ≥1 000 ml postpartum hemorrhage group according to the amount of blood loss during cesarean section. Differences in continuous variables were analyzed by t-test and categorical variables were analyzed by χ2 test. The risk factors of postpartum hemorrhage were analyzed by logistic multivariate regression. Results: A total of 962 puerperae were enrolled with 773 cases in the control group and 189 cases in the postpartum hemorrhage group. The incidence of gestational weeks, gravidity, parity, induced abortion, placental accreta and preoperative hemoglobin<110 g/L was significantly different between two groups in different types of placenta previa (P<0.001). Logistic multivariate regression model analysis showed that the independent risk factors of postpartum hemorrhage in the caesarean section of low-lying placenta included placental accreta (OR=12.713, 95%CI: 4.296-37.625), preoperative hemoglobin<110 g/L (OR=2.377, 95%CI: 1.062-5.321), and prenatal vaginal bleeding (OR=4.244, 95%CI: 1.865-9.656). The independent risk factors of postpartum hemorrhage in the caesarean section of placenta previa included once induced abortion (OR=2.789, 95%CI:1.189-6.544), induced abortion≥2 (OR=2.843, 95%CI:1.101-7.339), placental accreta (OR=6.079, 95%CI:3.697-9.996), HBsAg positive (OR=3.891, 95%CI:1.385-10.929), and placental attachment to the anterior uterine wall (OR=2.307, 95%CI:1.285-4.142). The rate of postpartum hemorrhage and premature delivery in puerperae with placenta previa was higher than that in puerperae with low-lying placenta (P<0.001). Conclusions: The associated factors of postpartum hemorrhage in puerperae with different types of placenta previa are different. Placenta accreta is the common risk factor of postpartum hemorrhage in puerperae with low-lying placenta and placenta previa.目的： 探讨不同类型前置胎盘产妇剖宫产产后出血的关联因素及妊娠结局。 方法： 本研究为回顾性的病例对照研究。收集2019年1月至2020年12月浙江大学医学院附属妇产科医院收治的因前置胎盘行剖宫产的产妇。根据术中出血量分为<1 000 ml的对照组和≥1 000 ml的产后出血组。分析产后出血在不同类型前置胎盘产妇中的关联因素及不良妊娠结局。采用t检验或χ2检验比较两组间的差异，采用logistic回归模型分析产后出血的关联因素。 结果： 共纳入研究对象962例，产后出血产妇189例，对照组产妇773例。在不同类型的前置胎盘产妇中，两组产妇的孕次、产次、孕周、人工流产次数、胎盘植入和术前血红蛋白<110 g/L的差异有统计学意义（均P<0.05）。logistic回归模型分析显示，胎盘植入（OR=12.713，95%CI：4.296~37.625），术前血红蛋白<110 g/L（OR=2.377，95%CI：1.062~5.321），产前阴道出血（OR=4.244，95%CI：1.865~9.656）是低置胎盘产妇产后出血风险的危险因素；人工流产1次（OR=2.789，95%CI：1.189~6.544），人工流产≥2次（OR=2.843，95%CI：1.101~7.339）、胎盘植入（OR=6.079，95%CI：3.697~9.996）、HBsAg阳性（OR=3.891，95%CI：1.385~10.929）和胎盘附着子宫前壁（OR=2.307，95%CI：1.285~4.142）是前置胎盘产妇产后出血的危险因素。前置胎盘产妇的产后出血率和早产率高于低置胎盘产妇（P<0.001）。 结论： 不同类型前置胎盘产妇产后出血的关联因素有所不同，胎盘植入是导致低置胎盘和前置胎盘产妇产后出血的共同危险因素。.