低风险初产妇产后出血风险预测

目的探讨低风险初产妇产后出血的相关危险因素并建立与之相应的预测模型,为早期识别产后出血和及时给予干预措施提供依据。方法选取2017年5月至2019年7月在北京某三级甲等综合医院规律产检并经阴道分娩、无妊娠合并症或其他妊娠风险的低风险初产妇600例,年龄18~34岁。其中经阴道分娩后发生产后出血(>500 mL)的300例为病例组,同期阴道分娩产后出血量小于300 mL的300例为对照组。采用多因素Logistic回归模型探讨低风险产妇产后出血影响因素并建立预测模型。结果单因素分析显示,病例组产妇年龄、孕周、分娩前血红蛋白、第二产程时间、第三产程时间、会阴侧切和新生儿体重与对照组差异具有统计学意义。多变量Logistic回归结果显示,年龄、第二产程时间(/10 min)、第三产程时间、会阴侧切、新生儿体重(/100 g)均为产后出血的危险因素,OR值分别为1.10(95%CI:1.02~1.18)、1.05(95%CI:1.01~1.09)、1.07(95%CI:1.03~1.12)、1.44(95%CI:1.01~2.05)、1.12(95%CI:1.06~1.19),分娩前血红蛋白(/10 g/L)为产后出血的保护因素,OR值为0.65(95%CI:0.56~0.76)。利用上述回归模型预测低风险初产妇产后出血发生概率的列线图,显示预测模型C-index为0.71(95%CI:0.67~0.75)。结论年龄、第二产程时间、第三产程时间、会阴侧切和新生儿体重为低风险初产妇产后出血的独立危险因素,分娩前血红蛋白为低风险初产妇产后出血的保护因素。

Prediction of postpartum hemorrhage among low-risk primiparas

Objective To investigate the risk factors of postpartum hemorrhage and construct prediction model of postpartum hemorrhage among low-risk primiparas.Methods A total of 600 low risk primiparas who were aged 18-34 years,underwent regular obstetric examination,had no gestational complications,and delivered vaginally were identified from a tertiary hospital in Beijing from May 2017 to July 2019,including 300 women with postpartum hemorrhage≥500 mL(case group)and 300 matched controls with postpartum bleeding<300 mL.All data were retrieved from electronic medical records.Multivariable logistic regression was used to explore potential risk factors of postpartum hemorrhage and develop a prediction model of postpartum hemorrhage.Results In the univariate analysis,maternal age,gestational week,duration of the second stage of labor,duration of the third stage of labor,prepartum hemoglobin,perineal incision,and neonatal weight were all significantly different(P<0.05)between the two groups.Multivariable logistic regression showed that five factors including age(year),duration of the second stage of labor(/10 minutes),duration of the third stage of labor(minute),lateral perineal resection,and newborn weight(/100 g)were the independent risk factors of postpartum hemorrhage;the corresponding ORs were 1.10(95%CI:1.02-1.18),1.05(95%CI:1.01-1.09),1.07(95%CI:1.03-1.12),1.44(95%CI:1.01-2.05),and 1.12(95%CI:1.06-1.19),respectively.The pre-partum hemoglobin(/10 g/L)was the protective factor of postpartum hemorrhage,and the corresponding OR was 0.65(95%CI:0.56-0.76).The c-index of the prediction model was 0.71(95%CI:0.67-0.75),and a nomogram predicting postpartum hemorrhage in low-risk primiparas was established.Conclusion For low-risk primiparas,maternal age,duration of the second stage of labor,duration of the third stage of labor,perineal lateral incision,and birth weight are independent risk factors of postpartum hemorrhage,while prepartum hemoglobin is a protective factor of postpartum hemorrhage.