Department of Ultrasound, Dalian Women and Children's Medical Group, Dalian, China (Dr Liu, Ms Yang, and Ms Jiang).
Department of Ultrasound, Dalian Municipal Central Hospital affiliated with the Dalian Medical University, Dalian, China (Dr Yue).
Am J Obstet Gynecol MFM. 2023 Feb;5(2):100804. doi: 10.1016/j.ajogmf.2022.100804. Epub 2022 Nov 11.
Cervical length is a commonly used clinical indicator for evaluating preterm birth. However, some studies have shown that cervical length does not change in patients with cervical insufficiency.
This study aimed to use the transvaginal ultrasound E-Cervix to quantitatively evaluate the cervical stiffness in women with singleton and twin pregnancies to provide a reference for the clinical prediction of preterm birth.
We collected the cervical length, cervical hardness ratio, mean internal os strain, and mean external os strain using transvaginal ultrasonographic E-Cervix assessments in pregnant women undergoing routine examinations in the obstetrics department of our hospital from January 2020 to December 2020. We summarized the range of cervical elasticity parameters at different gestational ages and compared the cervical elasticity parameters between singleton and twin pregnancies and between preterm births and full-term births.
A total of 988 pregnant women were enrolled in this study, and after exclusion, 770 pregnant women were enlisted; the interrater and internal consistency for various elasticity parameters were favorable; and cervical elasticity changes in women at full term showed some particular patterns. The declines in cervical length and hardness ratio were commensurate with gestational age, whereas the internal os strain and external os strain rose with increasing gestational age. The cervical hardness ratio in women with twin pregnancies was lower than in women with singleton pregnancies at the same gestational age, although the internal os strain in women with twin pregnancies was higher than in women with singleton pregnancies at the same gestational age (P<.05). The cervical length of women with twin pregnancies was shorter than that of women with singleton pregnancies at the same gestational age when the gestational age was ≥28 weeks of gestation (all P<.05), and the hardness ratio was linearly correlated with gestational age (r=0.68 and r=0.71). The regression model for the cervical hardness ratio in women with singleton pregnancies was hardness ratio = -0.8764×gestational age+100.99, whereas the regression model for the cervical hardness ratio in women with twin pregnancies was hardness ratio = -1.3037×gestational age+103.03. When we compared cervical elasticity parameters between preterm and full-term births, we noted that the cervical hardness ratio in pregnant women who exhibited preterm births was lower regardless of whether they carried singleton or twin pregnancies (P=.000 and P=.000), although their internal os strain was higher (P=.023 and P=.000). We observed no significant difference when we compared the cervical length and external os strain of pregnant women manifesting preterm births vs women with full-term births (P=.216 and P=.345 vs P=.475 and P=.363).
When used for the quantification of cervical hardness, the E-Cervix cervical elasticity changes in pregnant women at full term showed some particular patterns. Cervical length and hardness ratio diminished as gestational age increased, whereas internal os strain and external os strain rose as gestational age increased; moreover, the degree of these changes was greater in women with twin pregnancies than in women with singleton pregnancies. Pregnant women experiencing preterm births exhibited a reduced cervical hardness ratio and augmented internal os strain relative to women experiencing full-term births.
宫颈长度是评估早产的常用临床指标。然而，一些研究表明，在宫颈功能不全的患者中，宫颈长度不会改变。
本研究旨在使用经阴道超声 E-Cervix 对单胎和双胎妊娠患者的宫颈硬度进行定量评估，为早产的临床预测提供参考。
我们收集了 2020 年 1 月至 2020 年 12 月在我院妇产科进行常规检查的孕妇的宫颈长度、宫颈硬度比、内口平均应变和外口平均应变，使用经阴道超声 E-Cervix 评估。我们总结了不同妊娠龄段宫颈弹性参数的范围，并比较了单胎和双胎妊娠以及早产和足月产之间的宫颈弹性参数。
本研究共纳入 988 名孕妇，排除后，770 名孕妇被纳入；各种弹性参数的组内和组间一致性良好；足月妊娠妇女的宫颈弹性变化呈现出一些特殊模式。宫颈长度和硬度比与孕龄呈负相关，而内口应变和外口应变随孕龄增加而增加。在相同孕龄下，双胎妊娠妇女的宫颈硬度比低于单胎妊娠妇女，但双胎妊娠妇女的内口应变高于单胎妊娠妇女（P<.05）。在孕龄≥28 周时，双胎妊娠妇女的宫颈长度比单胎妊娠妇女短（均 P<.05），且硬度比与孕龄呈线性相关（r=0.68 和 r=0.71）。单胎妊娠妇女的宫颈硬度比回归模型为硬度比=-0.8764×孕龄+100.99，而双胎妊娠妇女的宫颈硬度比回归模型为硬度比=-1.3037×孕龄+103.03。当我们比较早产和足月产之间的宫颈弹性参数时，我们注意到，无论是否携带单胎或双胎，早产孕妇的宫颈硬度比都较低（P=.000 和 P=.000），尽管他们的内口应变较高（P=.023 和 P=.000）。我们比较早产孕妇和足月产孕妇的宫颈长度和外口应变时，差异无统计学意义（P=.216 和 P=.345 与 P=.475 和 P=.363）。
在定量评估宫颈硬度时，足月妊娠妇女的 E-Cervix 宫颈弹性变化呈现出一些特殊模式。宫颈长度和硬度比随孕龄增加而减小，而内口应变和外口应变随孕龄增加而增加；此外，双胎妊娠妇女的变化程度大于单胎妊娠妇女。与足月产孕妇相比，早产孕妇的宫颈硬度比降低，内口应变增加。
