彩色多普勒超声及脐动脉血流动力学指标在诊断胎盘植入中的应用价值

Value of color Doppler ultrasound and hemodynamic indicator of umbilical artery applied to diagnosis of placenta accreta

目的探讨产前彩色多普勒超声及脐动脉血流动力学指标在诊断胎盘植入中的应用价值。方法选取131例孕妇,均于孕晚期(28~34+6周)进行产前常规彩色多普勒超声检查并行脐动脉血流多普勒频谱检测,记录脐动脉收缩末期峰值与舒张末期峰值的比值(S/D)。以病理诊断为金标准,评价彩色多普勒超声诊断胎盘植入中的效能。分析脐动脉S/D值与胎盘植入的相关性,并采用受试者工作曲线分析脐动脉S/D值及其联合剖宫产次数、胎盘厚度诊断胎盘植入的效能。结果共28例病理检查确诊为胎盘植入,彩色多普勒超声检出22例,其诊断的敏感度、特异度、阳性预测值、阴性预测值分别为78.57%(22/28)、91.26%(94/103)、70.97%(22/31)、94.00%(94/100)。胎盘厚度、剖宫产次数、脐动脉S/D值均是胎盘植入的独立危险因素(均P<0.05)。单纯脐动脉S/D值、S/D值联合剖宫产次数、S/D值联合剖宫产次数及胎盘厚度诊断胎盘植入的曲线下面积分别为0.708、0.861、0.894。结论彩色多普勒超声在诊断胎盘植入中有较好的应用价值。脐动脉S/D值可作为产前诊断辅助胎盘植入的指标,其联合剖宫产次数、胎盘厚度时可提高诊断胎盘植入的效能。

Objective To Investigate the value of prenatal color Doppler ultrasound and hemodynamic indicator of umbilical artery applied to diagnosis of placenta accreta. Methods A total of 131 pregnant women were enrolled in the study. In the third trimester（24 to 34 ＋ 6 weeks of gestational age）,the subjects underwent conventional prenatal color Doppler ultrasound and Doppler spectrum of umbilical artery blood flow,then the ratio of peak systolic velocity to end diastolic velocity（S/D） was recorded. The pathologically diagnostic result was taken as gold standard,and the diagnostic efficiency of color Doppler ultrasound for placenta accreta was assessed. The correlation of umbilical artery S/D ratio with placenta accreta was analyzed. Receiver operating characteristic curve was used to analyze the diagnostic efficiency of umbilical artery S/D ratio,umbilical artery S/D ratio combined with frequency of cesarean section and placental thickness for placenta accreta. Results The pathological findings showed that 28 cases were diagnosed as placenta accreta,and 22 cases were screened out by color Doppler ultrasound. The diagnostic sensitivity,specificity,positive predictive value and negative predictive value of color Doppler ultrasound were 78. 57%（22/28）,91. 26%（94/103）,70. 97%（22/31） and 94. 00%（94/100） respectively. The placental thickness,frequency of cesarean section,and umbilical artery S/D ratio were the independent risk factors for placenta accreta（all P〈0. 05）.The areas under curve for umbilical artery S/D ratio alone,S/D ratio combined with frequency of cesarean section,S/D ratio combined with frequency of cesarean section and placental thickness in the diagnosis of placenta accreta were 0. 708,0. 861 and 0. 894 respectively.Conclusion Color Doppler ultrasound obtains favorable application value in the diagnosis of placenta accreta. Umbilical artery S/D ratio can serve as an indicator for prenatal auxiliary diagnosis of placenta accreta,and its combination with frequency of cesarean section and placental thickness can improve the diagnostic efficiency for placenta accreta.