Academic Unit of Reproductive and Developmental Medicine, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK.
Medical Physics and Clinical Engineering, University of Sheffield, Sheffield, UK.
Ultrasound Obstet Gynecol. 2021 Aug;58(2):293-302. doi: 10.1002/uog.22180.
Preterm birth (PTB) accounts for two-thirds of deaths of structurally normal babies and is associated with substantial lifetime healthcare costs. Prevention of PTB remains limited by the modest accuracy of prediction methods, namely transvaginal ultrasound (TVS) cervical length (CL) measurement and quantitative cervicovaginal fetal fibronectin (FFN) estimation. We report the first substantive study detailing the predictive performance of a cervical probe device based on electrical impedance spectroscopy (EIS) for PTB - the EleCtriCaL Impedance Prediction of Preterm birth by spectroscopy of the cervix (ECCLIPPx) study. We aimed to compare the accuracy of cervical EIS-based prediction of spontaneous PTB with that of prediction using TVS-CL and FFN in asymptomatic women in the mid-trimester.
We studied asymptomatic women with a singleton pregnancy at 20-22 weeks' and 26-28 weeks' gestation. EIS was performed using a Sheffield Mark 5.0 device that makes measurements in the frequency range 76 Hz to 625 kHz using a small probe housing tetrapolar electrodes. TVS-CL and FFN were also measured. The associations of cervical EIS, TVS-CL and FFN with spontaneous delivery before 37 weeks and before 32 weeks were determined by multivariate linear and non-linear logistic regression analysis. Areas under the receiver-operating-characteristics curves (AUC) plots of sensitivity against specificity were used to compare the predictive performance of all parameters, both in isolation and in combination.
Of the 365 asymptomatic women studied at 20-22 weeks who were not receiving treatment, 29 had spontaneous PTB, 14 had indicated PTB and 322 had term birth. At the higher frequencies assessed, cervical EIS predicted spontaneous PTB before 37 weeks with an AUC of 0.76 (95% CI, 0.71-0.81), compared with AUCs of 0.72 (95% CI, 0.66-0.76) for TVS-CL and 0.62 (95% CI, 0.56-0.72) for FFN. Combining all three assessments improved the prediction of spontaneous PTB before 37 weeks (AUC, 0.79 (95% CI, 0.74-0.83)) compared with TVS-CL and FFN alone. Incorporating a history of spontaneous PTB (defined as previous mid-trimester miscarriage or spontaneous PTB (14 to < 37 weeks)) into the cervical EIS prediction model improved the accuracy of prediction of spontaneous PTB before 37 weeks (AUC, 0.83 (95% CI, 0.78-0.87)) and before 32 weeks (AUC, 0.86 (95% CI, 0.82-0.90)).
Mid-trimester cervical EIS assessment predicts spontaneous PTB. Larger confirmatory studies investigating its potential clinical utility and to inform effective preventive interventions are required. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
早产（PTB）占结构正常婴儿死亡人数的三分之二，并且与大量终生医疗保健费用有关。早产的预防仍然受到预测方法准确性的限制，即经阴道超声（TVS）宫颈长度（CL）测量和定量宫颈阴道胎儿纤维连接蛋白（FFN）估计。我们报告了第一项详细描述基于电阻抗谱（EIS）的宫颈探头设备预测早产的实质性研究-电阻抗预测早产的宫颈光谱（ECCLIPPx）研究。我们旨在比较基于宫颈 EIS 的自发性 PTB 预测的准确性与 TVS-CL 和 FFN 在中期无症状妇女中的预测准确性。
我们研究了 20-22 周和 26-28 周妊娠的无症状单胎孕妇。使用 Sheffield Mark 5.0 设备进行 EIS 测量，该设备使用小探头外壳中的四极电极在 76 Hz 至 625 kHz 的频率范围内进行测量。还测量了 TVS-CL 和 FFN。通过多元线性和非线性逻辑回归分析确定宫颈 EIS、TVS-CL 和 FFN 与 37 周前和 32 周前自发性分娩的关联。使用接收器操作特性曲线（ROC）的灵敏度与特异性之间的面积（AUC）图来比较所有参数的预测性能，包括单独和组合使用时的性能。
在 20-22 周接受治疗的 365 名无症状妇女中，有 29 名发生自发性 PTB，14 名发生指征性 PTB，322 名发生足月分娩。在评估的较高频率下，宫颈 EIS 预测 37 周前自发性 PTB 的 AUC 为 0.76（95%CI，0.71-0.81），而 TVS-CL 的 AUC 为 0.72（95%CI，0.66-0.76），FFN 的 AUC 为 0.62（95%CI，0.56-0.72）。与 TVS-CL 和 FFN 单独相比，合并所有三种评估可改善 37 周前自发性 PTB 的预测（AUC，0.79（95%CI，0.74-0.83））。将自发性 PTB 的病史（定义为中期流产或自发性 PTB（14 至 <37 周））纳入宫颈 EIS 预测模型可提高 37 周前自发性 PTB 的预测准确性（AUC，0.83（95%CI，0.78-0.87））和 32 周前（AUC，0.86（95%CI，0.82-0.90））。
中期宫颈 EIS 评估可预测自发性 PTB。需要更大的确认性研究来调查其潜在的临床效用，并为有效的预防干预措施提供信息。
