Departments of Obstetrics and Gynecology, NYU Langone Hospital-Long Island, NYU Long Island School of Medicine, Mineola, NY.
Departments of Obstetrics and Gynecology, NYU Langone Hospital-Long Island, NYU Long Island School of Medicine, Mineola, NY.
Am J Obstet Gynecol. 2021 Nov;225(5):525.e1-525.e9. doi: 10.1016/j.ajog.2021.05.017. Epub 2021 May 27.
Accurate identification of the women who will have spontaneous preterm birth continues to be a great challenge. The use of cervical elastography for prediction of preterm birth is promising, but several limitations exist. Newer cervical elastography technology has been developed that may prove useful in evaluation of risk of preterm birth.
This study aimed to develop standard cervical elastography nomograms for singleton pregnancies at 18 to 22 weeks' gestation using the E-Cervix ultrasound application, assess intraobserver reliability of the E-Cervix elastography parameters, and determine whether these cervical elastography measurements can be used in the prediction of spontaneous preterm birth.
This was a prospective cohort study of pregnant women undergoing cervical length screening assessment via transvaginal ultrasound examination at 18 to 22 weeks' gestation. A semiautomatic, cervical elastography application (E-Cervix) was used during the transvaginal examination to calculate 5 quantitative parameters (internal os stiffness, external os stiffness, internal -to -external os stiffness ratio, hardness ratio, and elasticity contrast index) and create a standard nomogram for each one of them. The intraobserver reliability was calculated using Shrout-Fleiss reliability. Cervical elastography parameters were compared between those who delivered preterm (<37 weeks) spontaneously and those who delivered full term. A multivariable logistic regression model was performed to determine the ability of the cervical elastography parameters to predict spontaneous preterm birth.
A total of 742 women were included, of which 49 (6.6%) had a spontaneous preterm delivery. A standard nomogram was created for each of the cervical elastography parameters from those who had a full-term birth in the index pregnancy (n=693). Intraobserver reliability was good or excellent (intraclass correlation, 0.757-0.887) for each of the cervical elastography parameters except external os stiffness which was poor (intraclass correlation, 0.441). In univariate analysis, none of the cervical elastography parameters were associated with a statistically significant increased risk of spontaneous preterm birth. In a multivariable model adjusting for history of preterm birth, gravidity, ethnicity, cervical cerclage, and vaginal progesterone use, increasing elasticity contrast index was significantly associated with an increased risk of spontaneous preterm birth (odds ratio, 1.15; 95% confidence interval, 1.02-1.30; P=.02).
Cervical elastography parameters are reliably measured and are stable across 18 to 22 weeks' gestation. Based on our findings, the elasticity contrast index was associated with an increased risk of spontaneous preterm birth and may be a useful parameter for future research.
准确识别哪些女性会发生自发性早产仍然是一个巨大的挑战。使用宫颈弹性成像预测早产有一定的前景，但仍存在一些局限性。新的宫颈弹性成像技术已经得到了发展，这可能有助于评估早产的风险。
本研究旨在使用 E-Cervix 超声应用程序为 18 至 22 周妊娠的单胎妊娠制定标准的宫颈弹性成像图表，评估 E-Cervix 弹性成像参数的观察者内可靠性，并确定这些宫颈弹性测量值是否可用于预测自发性早产。
这是一项前瞻性队列研究，纳入了在 18 至 22 周妊娠时通过经阴道超声检查进行宫颈长度筛查评估的孕妇。在经阴道检查期间使用半自动宫颈弹性成像应用程序（E-Cervix）来计算 5 个定量参数（内口硬度、外口硬度、内外口硬度比、硬度比和弹性对比指数），并为每个参数创建标准图表。使用 Shrout-Fleiss 可靠性来计算观察者内可靠性。比较了自发性早产（<37 周）和足月分娩的孕妇之间的宫颈弹性成像参数。使用多变量逻辑回归模型来确定宫颈弹性成像参数预测自发性早产的能力。
共纳入 742 名孕妇，其中 49 名（6.6%）自发性早产。为在本次妊娠中足月分娩的孕妇（n=693）中的每一个宫颈弹性成像参数都创建了一个标准图表。除外口硬度的观察者内可靠性较差（组内相关系数为 0.441）外，每个宫颈弹性成像参数的观察者内可靠性均为良好或优秀（组内相关系数为 0.757-0.887）。单变量分析显示，没有任何宫颈弹性成像参数与自发性早产的风险显著增加相关。在调整早产史、孕次、种族、宫颈环扎术和阴道用黄体酮使用等因素的多变量模型中，增加的弹性对比指数与自发性早产的风险增加显著相关（比值比，1.15；95%置信区间，1.02-1.30；P=.02）。
宫颈弹性成像参数可以可靠地测量，并且在 18 至 22 周妊娠期间是稳定的。基于我们的研究结果，弹性对比指数与自发性早产的风险增加相关，可能是未来研究的有用参数。
