Clinical Value Of Cervical Stiffness Measured By Ultrasound And Cervical Real-time Tissue Elastography For Predicting The Risk Of PTB In Pregnant Women

Objective To explore the value of transperineal ultrasound and cervical real-time tissue elastography in predicting the risk of preterm birth(PTB)in pregnant women.Methods A total of 76 pregnant woman who was underwent regular antenatal examination and ultrasound in our hospital were seleced as subjects.Then,the subjects were divided into case group and control group according to their clinical manifestation.Both group were examined by two-dimensional gray-scale ultrasound to measure CL,the shape of cervical funnel was observed when it appeared,the flow parameters RI,PI,S/D of uterine artery were measured by two-dimensional color doppler ultrasound.Ultrasonic elastic imaging was used to evaluate the soft hardness of different interestr egions of cervix,which could obtain the corresponding elastic strain rate automatically,after that we recorded the corresponding ultrasonic examination data.Finally,we collecte the clinical data of the subjects and follow up the pregnancy outcome,then analyze and compare the differences of both the ultrasound indexes mentioned above,and the clinical data and pregnancy outcome between the two groups,and analyze the predictive value of conventional ultrasound and real-time tissue elastography for the risk of premature birth.Results CL in the case group was significantly shorter than that in the control group during second and third trimester.when 3.17 cm and 2.83 cm were used as the CL critical values to predict the risk of preterm birth second and third trimester,the sensitivity were85.7%、61.5%,the specificity were 80.0%、87.9%,the AUC were 0.786、0.781 respectively.The formation rate of cervical funnel in the case group was 18.2%,and that in the control group was 2.3%,those difference between the two groups was statistically significant(P<0.05).The sensitivity and specificity of cervical funnel as a predictor of PTB risk were 42.9% and 94.2%,respectively.The parameters of uterine artery related blood flow in the case group were slightly higher than those in the control group,but there were no significant difference between the two groups(P > 0.05).The elastic strain rate values of different regions of interest of cervix are different,the elastic strain rate of the internal and superior cervical lip and the internal and inferior cervical lip of cervix was higher than that in the control group(P<0.05).In the second trimester,the elastic strain rate of the internal and superior cervical lip was 0.285%,the elastic strain rate of the internal and inferior cervical lip was 0.185%,the sensitivity of predicting the risk of PTB were100%、100%,the specificity were 80.0%、70.0% and the AUC were 0.914、0.879.In the third trimester,the elastic strain rate of the internal and superior cervical lip was 0.335%,the elastic strain rate of the internal and inferior cervical lip was 0.235%,the sensitivity of predicting the risk of PTB were 69.2%、65.4%,the specificity were 87.9%、69.7%and the AUC were 0.814、0.714.The sensitivity,specificity and AUC of predicting the risk of PTB by combing with the elastic strain rate of the internal and superior cervical lip and the CL during the second trimester were 85.7%、100%、0.957 respectively and it were 88.5%、75.8%、0.861 respectively in the third trimesterConclusion The changes in cervical morphology can be reflected directly by Twodimensional ultrasound,The best critical value of CL in predicting PTB risk was 3.17 cm and 2.83 cm in the second and third trimester respectively.In the case of short cervix,the risk of premature birth was higher in the case of U-shaped cervical dilatation,and the risk of cervical funnel formation in predicting PTB had higher specificity and lower sensitivity.The elastic strain rate of the internal and superior cervical lip and the internal and inferior cervical lip of the cervix has a certain value in predicting the risk of PTB.What,s more the best critical value of the two is 0.285% and 0.185% respectively in the second trimester,and 0.335%、0.235% respectively in the third trimester.The combinati-on of Two dimensional ultrasound and real-time tissue elastography can better reflect the shape and function changes of cervical tissue,provide more accurate information for clinicians to assess the risk of PTB,and have great significance for clinical prediction of PTB risk.