产前超声诊断前置胎盘并胎盘植入的价值

Diagnostic value of prenatal ultrasound for placenta previa and placenta accreta

目的探讨产前超声诊断前置胎盘并胎盘植入的价值。方法收集2017年1月至2018年12月于我院接受产前检查确诊为前置胎盘的孕妇72例,均行产前二维超声、彩色多普勒超声检查并行剖宫产术。按是否存在胎盘植入分为植入组(n=29)与非植入组(n=43)。分析孕妇年龄、孕产史等临床参数与胎盘植入的关系,比较两组胎盘血管化指数(VI)、血流指数(FI)、血管化血流指数(VFI),分析产前超声诊断前置胎盘并胎盘植入的价值。结果植入组年龄≥35岁、有剖宫产史、流产次数>2次、孕次≥3次所占比例均高于非植入组(均P<0.05)。植入组超声声像图见胎盘后间隙部分或完全消失20例(68.97%),胎盘附着处子宫肌层菲薄、胎盘与子宫肌层界限不清11例(37.93%),胎盘内陷窝征23例(79.31%),胎盘异常增厚5例(17.24%)。植入组VI、FI、VFI均高于非植入组(均P<0.05)。VFI截断值为7.92时诊断胎盘植入的敏感度、特异度分别为93.10%、90.70%;VI截断值为18.05时诊断胎盘植入的敏感度、特异度分别为86.21%、79.07%;FI截断值为33.61时诊断胎盘植入的敏感度、特异度分别为82.76%、58.14%。结论前置胎盘合并胎盘植入时,胎盘、膀胱壁血流增加,胎盘血管化程度较高。三维能量多普勒成像可定量评估胎盘血管化程度,为产前胎盘植入评定提供依据。

Objective To determine the clinical value of prenatal ultrasound in diagnosis of placenta previa and placenta accreta.Methods The clinical data of 72 pregnant women with confirmed placenta previa in our hospital between January 2017 and December 2018 were collected.All pregnant women underwent prenatal ultrasound examination,including two-dimensional ultrasound and color Doppler ultrasound,and cesarean section.According to presence of placenta accreta,the subjects were divided into accreta group(n=29)and non-accreta group(n=43).The association between placenta accreta and clinical data such as patient age and gestational history was analyzed.The differences in placental vascularization index(VI),flow index(FI)and vascularization-flow index(VFI)were compared between the two groups.The diagnostic value of prenatal ultrasound for placenta previa and placenta accreta was determined.Results The proportions of pregnant women with age≥35 years old,cesarean section history,>two abortions,≥three gestations were higher in the accreta group than those in non-accreta group(all P<0.05).Of the accreta group,ultrasound identified 20 women(68.97%)with partial or complete vanishment of posterior placenta space,11(37.93%)with thin myometrium at placenta attachment or unclear placenta-myometrium boundary,23(79.31%)with placental lacuna sign,and 5(17.24%)with abnormal thickening of placenta.The values of VI,FI and VFI in the accreta group were higher than those in the non-accreta group(all P<0.05).The sensitivity and specificity for diagnosing placent accreta 93.10%and 90.70%by VFI with a cut-off value of 7.92,86.21%and 79.07%by VI with a cut-off value of 18.05,and 82.76%and 58.14%by FI with a cut-off value of 33.61,respectively.Conclusion In placenta previa complicated with placenta accreta,increased blood flow in placenta and bladder wall gives rise to relatively high placental vascularization.Three-dimensional power Doppler imaging may quantitatively measure the degree of placental vascularization and thereby offer a reliable basis for evaluation of prenatal placental accreta.