探讨经阴道超声实时宫颈组织弹性成像技术预测早产风险的应用价值。

选取2017年1至11月在北京妇产医院行产前检查的孕妇108名。其中29名孕妇临床诊断为先兆早产或早产临产（早产组）；余79名孕妇临床诊断无先兆早产或早产临产（正常组）。采用经阴道超声检查测量宫颈长度（CL），同时采用声弹性成像技术获得宫颈组织应变超声弹性成像参数，即完整宫颈应变率（CS）、宫颈内口应变率（IS）、宫颈外口应变率（ES）。采用独立样本t检验比较早产组与正常组孕妇CL、CS、IS、ES差异；绘制CL、CS、IS、ES预测孕妇早产风险的受试者工作特征（ROC）曲线。

早产组孕妇CL较正常组孕妇缩短[（2.94±0.66）cm vs （3.91±0.71）cm]，IS较正常组孕妇增加[（0.40±0.30）% vs （0.24±0.19）%]，且差异均有统计学意义（t=6.436，P<0.001；t=3.406，P=0.001）；早产组孕妇CS、ES均较正常组孕妇增加[（0.53±0.28）% vs （0.47±0.20）%，（0.74±0.39）% vs （0.73±0.37）%]，但差异均无统计学意义（t=1.365，P=0.175；t=0.207，P=0.837）。ROC曲线显示，CL、CS、IS、ES预测孕妇早产风险的ROC曲线下面积分别为0.156、0.558、0.689、0.499。IS的ROC曲线下面积相对较大，其预测孕妇早产风险的最佳阈值为0.30%，敏感度、特异度、准确性、阳性预测值及阴性预测值分别为66.7%、79.3%、71.1%、55.4%、80.2%。

利用声弹性成像技术获得孕妇宫颈组织弹性指标对预测不同孕周发生早产风险具有一定的临床诊断价值，其中IS在预测早期或无症状性早产方面可能更具有临床指导意义。

To assess the application value of trans-vaginal ultrasound and real-time sono-elastography in assessing the risk of preterm birth in pregnant women.

A total of 108 pregnant women who received prenatal examination at Beijing Obstetrics and Gynecology Hospital from January to November 2017 were included. Based on the presence of threatened premature or preterm labor or not, they were divided into a study group (n=29, with threatened premature or preterm labor) and a control group (n=79, with no threatened premature or preterm labor). Cervical length (CL) was measured by trans-vaginal ultrasound, and the following three cervical elasticity indexes were obtained by sono-elastography: the entire cervical strain rate (CS), the internal cervical os strain rate (IS), and external cervical os strain rate (ES). Independent samples t-test was used to analyze the difference in the above indexes between the two groups. Receiver operating characteristic (ROC) curve analysis was performed to assess the value of the above indexes in predicting the risk of preterm birth.

CL was significantly lower [(2.94±0.66) cm vs (3.91±0.71) cm] and IS was significantly higher [(0.53±0.28)% vs (0.47±0.20)%] in the study group than in the control group (t=6.436, 3.406, both P<0.05). CS and ES in the study group were higher than those in the control group [(0.40±0.30)% vs (0.24±0.19)%, (0.74±0.39)% vs (0.73±0.37)%], but the differences were not statistically significant (t=1.365, 0.207, both P>0.05). ROC curve analysis indicated that CL, CS, IS, and ES performed differently in assessing the risk of preterm birth in pregnant women [area under the ROC curve (AUC): 0.156, 0.558, 0.689, 0.499]. The AUCs of CS and IS were greater than 0.50, and the AUC of IS was larger than those of other indexes. Using 0.30% as a cut-off for IS, its sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 66.7%, 79.3%, 71.1%, 55.4%, and 80.2%, respectively.

Cervical tissue elasticity indexes obtained by sono-elastography can be used to assess pregnant women at different gestational ages and predict the risk of preterm birth feasibly. IS is more useful than other indexes in predicting early or asymptomatic preterm birth.