目的：探讨产前胎儿胎盘弹性平均值和脐动脉S/D对胎儿预后不良预测的可能性。方法：选择我院就诊孕妇150例，孕周37~40周，采用实时剪切波弹性成像超声诊断仪进行胎盘弹性值及脐动脉S/D测量,观察胎儿预后不良的情况。应用ROC曲线分析胎盘弹性平均值，获取能预测胎儿预后不良的最佳临界值，采用该临界值进行分组，比较两组间脐动脉S/D值有无差异。结果：胎盘弹性平均值预测胎儿预后不良的ROC曲线下面积为0.86，诊断界值为26.5 kPa，诊断敏感度为82.4%，特异度为80.7%，两组间脐动脉S/D值差异有显著性（P<0.05）；胎盘弹性平均值与脐动脉S/D呈正相关，相关系数为r=0.822（P<0.05）。结论：胎盘弹性平均值与脐动脉S/D联合应用可提高超声对胎儿预后不良进行预测的能力。

Objective: To investigate whether the elastic value of placenta and umbilical artery S/D can predict poor prognosis of fetus, and analyze the relationship between them. Methods: One hundred and fifty cases of pregnant women were selected with gestation weeks of 37~40. By SuperSonic Imagine Aix Plorer real-time shear wave elastography ultrasound diagnostic apparatus, the elastic value of placenta and umbilical artery S/D were measured before childbirth and poor prognosis of fetus was observed. Finally, the elastic value of placenta was analyzed by ROC curve, to find the optimal critical value which can predict poor prognosis of fetus. Two groups were divided by the critical value, then comparison was made between the difference of umbilical artery S/D and the elastic value. Results: On ROC curve, the area under the curve(AUC) of the elastic value of placenta was 0.86 and the threshold of diagnosing poor prognosis of fetus was 26.5 kPa with a sensitivity of 82.4% and a specificity of 80.7%. There was a significant difference(P<0.05) of umbilical artery S/D between two groups(≥26.5 kPa and <26.5 kPa). The elastic value of placenta was positively correlated with umbilical artery S/D(r=0.822, P<0.05). Conclusion: It will help to predict the prognosis of fetus by combining the elastic value of placenta with umbilical artery S/D.