脑胎盘率对延期妊娠引产发生不良围产结局的预测作用

Predictive value of cerebroplacental ratio for perinatal outcomes of induction of labor in prolonged pregnancy

目的探讨脑胎盘率对延期妊娠引产发生不良围产结局的预测作用。方法回顾性纳入2019年1月1日至2020年4月30日在重庆医科大学附属第一医院因延期妊娠(≥孕41周)引产的单胎妊娠孕妇315例。按照是否出现不良围产结局(因持续异常胎心监护需紧急分娩、出生时脐动脉血pH<7.2、5 min Apgar评分<7分、生后转入新生儿重症监护病房、发生绒毛膜羊膜炎以及中转剖宫产)分为不良围产结局组(76例)和良好围产结局组(239例)。采用两独立样本t检验、Mann-Whitney U检验、χ2检验比较组间一般情况及引产前最后一次超声测量的胎儿脐血流、大脑中动脉血流和脑胎盘率的差异,绘制受试者工作特性曲线分析各血流指标对不良围产结局的预测作用,采用多因素logistic回归分析筛选最终有意义的预测指标。结果不良围产结局组脐动脉搏动指数(0.9±0.1与0.8±0.1,t=-5.458,P<0.001)和脑胎盘率异常(<1.0)比例高于良好围产结局组[21.1%(16/76)与6.3%(15/239),χ^(2)=14.190,P<0.001],大脑中动脉搏动指数(1.1±0.2与1.3±0.3,t=5.658,P<0.001)和脑胎盘率低于良好围产结局组(1.2±0.3与1.6±0.5,t=8.940,P<0.001)。脐动脉搏动指数、大脑中动脉搏动指数和脑胎盘率预测不良围产结局的受试者工作特性曲线下面积分别为0.71、0.71和0.77。脑胎盘率的灵敏度(0.74)高于脐动脉搏动指数(0.68)和大脑中动脉搏动指数(0.71),但三者的特异度相近,分别为0.67、0.66和0.66。多因素回归分析显示只有脑胎盘率是不良围产结局的独立危险因素(OR=0.028,95%CI:0.010~0.080,P<0.001)。结论脑胎盘率作为早期预测延期妊娠发生不良围产结局的指标具有较高的灵敏度,但特异度稍差。

Objective To investigate the predictive value of cerebroplacental ratio(CPR)for adverse perinatal outcomes of induction of labor in prolonged pregnancy.Methods This retrospective study recruited 315 singleton pregnant women who had induced labor due to prolonged pregnancy(≥41 gestational weeks)in the First Affiliated Hospital of Chongqing Medical University from January 1,2019 to April 30,2020.Based on the occurrence of adverse perinatal outcomes(emergency delivery due to persistent abnormal fetal heart rate monitoring,umbilical artery blood pH at birth<7.2,5 min Apgar scores<7,transferring to neonatal intensive care unit after birth,chorioamnionitis and vaginal delivery converted to cesarean section),they were divided into two groups:case group(n=76)and normal group(n=239).Clinical features and umbilical artery blood flow,middle cerebral artery(MCA)flow and CPR measured in the last ultrasound scan before induction were compared between the two groups using student's t-test,Mann-Whitney U test and Chi-square test.Receiver operating characteristic(ROC)curve was used to analyze the predictive values of umbilical artery blood flow,MCA flow and CPR for the adverse perinatal outcomes.Multivariate logistic regression analysis was used to screen the meaningful predictors.Results Compared with the normal group,the umbilical artery pulsatility index(PI)(0.9±0.1 vs 0.8±0.1,t=-5.458,P<0.001)and the percentage of abnormal CPR(<1.0)increased significantly[21.1%(16/76)vs 6.3%(15/239),χ^(2) =14.190,P<0.001]in the case group,while the MCA-PI and CPR decreased significantly(1.1±0.2 vs 1.3±0.3,t=5.658,P<0.001;1.2±0.3 vs 1.6±0.5,t=8.940,P<0.001).The areas under the ROC curves of umbilical artery PI,MCA-PI and CPR for predicting adverse perinatal outcomes were 0.71,0.71 and 0.77,respectively.CPR had the highest sensitivity(0.74)compared with umbilical artery PI(0.68)and MCA-PI(0.71),but the specificity of them were similar(0.67,0.66 and 0.66).Multivariate logistic regression analysis showed that only CPR was the independent risk factor for adverse perinatal outcomes(OR=0.028,95%CI:0.010-0.080,P<0.001).Conclusions As an indicator for early prediction of adverse perinatal outcomes of induction of labor in prolonged pregnancy,CPR was more sensitive but less specific.