妊娠中期宫颈弹性参数联合宫颈长度对自发性早产的预测价值

Combination of cervical elastographic parameters and cervical length for the prediction of spontaneous preterm birth in second trimester of pregnancy

目的评估妊娠中期宫颈软硬度特点,探讨宫颈弹性参数联合宫颈长度(CL)对自发性早产(sPTB)的预测价值。方法回顾性分析2018年1月至2019年12月在成都市妇女儿童中心医院进行产前超声检查的147例足月产孕妇(足月产组)和24例sPTB孕妇(sPTB组)的临床资料。妊娠16~28周时采用经阴道超声E-Cervix技术测量CL与弹性参数[对比指数(ECI)、硬度比(HR)、宫颈内口应变平均值(IOS)、宫颈外口应变平均值(EOS)、宫颈内外口应变平均值比(IOS/EOS)]。比较足月产组与sPTB组CL及宫颈弹性参数的差异,并建立二分类Logistic回归模型,绘制单一及联合宫颈参数预测sPTB的ROC曲线,计算ROC曲线下面积(AUC)。结果sPTB组弹性参数IOS、IOS/EOS高于足月产组,HR和CL低于足月产组,差异有统计学意义(均P<0.05);两组间ECI、EOS差异无统计学意义(均P>0.05)。弹性参数IOS、IOS/EOS单独预测sPTB的AUC分别为0.684、0.625,高于HR、CL的AUC值。IOS与CL、IOS/EOS与CL联合预测sPTB的AUC高于单一弹性参数。IOS/EOS与CL联合预测sPTB的AUC最高为0.788,最佳截断值IOS/EOS为1.22,CL为3.46 cm,敏感性为70.8%,特异性为87.3%。结论妊娠中期sPTB孕妇宫颈硬度低于足月产孕妇,尤其宫颈内口更软。IOS/EOS联合CL对sPTB的预测价值较大,效能优于单一宫颈参数。

Objective To evaluate the characteristics of cervical hardness and softness in the second trimester,and to explore the predictive value of the combination of cervical elastographic parameters and cervical length(CL)in spontaneous preterm birth(sPTB).Methods The clinical data of 147 women with full-term birth(full-term birth group)and 24 women with sPTB(sPTB group)who received prenatal examination in Chengdu Women′s and Children′s Central Hospital from January 2018 to December 2019 were reviewed.Multiple parameters were measured between 16-28 gestational weeks by the transvaginal ultrasound E-cervix technique.CL,elasticity contrast index(ECI),hardness ratio(HR),mean strain at internal os(IOS),mean strain at external os(EOS),the ratio of IOS to EOS(IOS/EOS)were obtained.Elastographic parameters and CL were compared between the two groups.Furthmore,binary regression was established,while the area under ROC curve(AUC)was used to evaluate the predictive efficiency of elastographic parameters and CL in sPTB,both alone and in combination with other parameters.Results The elastographic parameters IOS and IOS/EOS in the sPTB group were higher than those in the full-term birth group,while HR and CL were lower than those in the full-term birth group(all P<0.05).There were no statistical differences of ECI and EOS between the two groups(both P>0.05).The AUCs of predicting sPTB with single IOS,IOS/EOS were 0.684 and 0.625,higher than the AUCs of HR,CL.The combination of IOS/EOS and CL,IOS and CL showed higher AUCs than elastographic parameters alone,with the AUC 0.788 of IOS/EOS combined with CL.The sensitivity was 70.8%,and the specificity was 87.3%corresponding to the optimum cutoff value(IOS/EOS was 1.22,CL was 3.46 cm).Conclusions In the second trimester,sPTB has a lower hardness cervix than that of full-term women,especially the internal os of cervix.The combination of IOS/EOS and CL tends to improve the ability of predicting sPTB in pregnant women.