Abstract：
UNASSIGNED: TVS (Transvaginal Sonography) guided Cervical strain elastography (CSE) is now available in tertiary referral centers of LMICs (Low- and Middle-Income Countries). TVS cervical length (CL) assessment is being used routinely. Still, elastography is not used in clinical settings, although enough evidence suggests good predictive value towards sPTD (spontaneous Preterm Delivery). The clinical utility of elastography has not been tested among high-risk populations of LMICs for the prediction of sPTD.
UNASSIGNED: To test the performance of TVS-CSE in predicting sPTD among asymptomatic women in the mid-trimester at risk of sPTD either due to clinical factors or due to a short cervix.
UNASSIGNED: Prospective observational study performed at a tertiary hospital in South India. Asymptomatic pregnant women between 16 and 24 weeks who had one or more clinical risk factors for sPTD or CL <2.5 cm were included. GE Voluson E-8 ultrasound machine was used. After CL measurement, elastography color coding was noted around the internal-os in the sagittal view. The strain ratio (SR) was calculated using the trace method on three ROIs (Region of Interest): Internal-os in sagittal view (IN), whole cervix in sagittal view (WN), and internal-os in axial view (AN). Reference Tissue (RT) of similar size and depth was chosen in the darkest blue region on elastography (stiffest area) outside the cervix, posterior/lateral to the cervix over the ligament insertion. Lower the SR - softer the cervix. Two trained fetal medicine consultants performed the initial 57 cases until intra/inter-observer correlation was satisfactory. Delivery before 37 weeks (after 26 weeks), in which the process of labor has begun spontaneously, or labor was induced after PPROM-was considered as sPTD. SRs were assessed to determine how well they could predict sPTD independently or combined with cervical length.
UNASSIGNED: Out of 221 recruited,17 were lost to follow-up after 32 weeks; 204 were delivered in our hospital. Irrespective of the route of delivery, 71 (34.8%) had sPTD. Of the remaining 133, 106 delivered at term, and 27 underwent medically indicated PTD. Apart from multiple pregnancies, no other preterm-related risk factors (including CL < 2.5 cm) showed significant association with sPTD. Red CSE pattern around internal-os was associated with a significantly higher (54.5%) incidence of sPTD. CLs were similar (3.63 ± 0.67 vs. 3.63 ± 0.80, p = .981) whereas SRs in all three ROIs were significantly lower among sPTD group versus no sPTD group (IN:0.65 ± 0.29 vs 0.79 ± 0.30 p = .001, WN:0.34 ± 0.13 vs 0.39 ± 0.15, p = .013, AN:0.37 ± 0.16 vs 0.48 ± 0.26, p = .002, respectively). Using ROC curves, while CL was not predictive (AUROC 0.49, p = .81), SRs showed moderate predictive value toward sPTD with the best AUC of 0.624 (p = .003) at IN. Prediction was slightly better for early sPTD <32 weeks (AUC 0.653 p = 0.03). The best cutoff for SR at IN was 0.72, below which there was a moderate accuracy in predicting sPTD (sensitivity 52.11%, specificity 60.9%, PPV 41.57%, NPV 70.44%, diagnostic OR 1.69 and overall accuracy of 57.84%). A weak positive correlation is seen between IN and CL (Pearson\'s correlation R = 0.181). Multi-variable binary logistic regression analysis suggested that SRs at IN (Adjusted OR - 0.259 CI 0.079-0.850), AN (Adjusted OR 0.182 CI 0.034-0.963), Multiple Pregnancy (Adjusted OR 3.5 CI 1.51-8.13) and previous sPTD/PPROM (Adjusted OR 2.72 CI 0.97-7.61) independently predicted sPTD.
UNASSIGNED: TVS CSE performed better than CL as an independent predictive tool toward sPTD, although predictive efficacy was modest at best. Since technology is now available in high-end USG machines in tertiary care centers, we propose optimal utilization of CSE in LMICs to triage at-risk populations since low SRs are strongly associated with sPTD.
UNASSIGNED: To test the performance of TVS-CSE in predicting sPTD among asymptomatic women in the mid-trimester at risk of sPTD either due to clinical factors or due to a short cervix.
UNASSIGNED: Prospective observational study performed at a tertiary hospital in South India. Asymptomatic pregnant women between 16 and 24 weeks who had one or more clinical risk factors for sPTD or CL <2.5 cm were included. GE Voluson E-8 ultrasound machine was used. After CL measurement, elastography color coding was noted around the internal-os in the sagittal view. The strain ratio (SR) was calculated using the trace method on three ROIs (Region of Interest): Internal-os in sagittal view (IN), whole cervix in sagittal view (WN), and internal-os in axial view (AN). Reference Tissue (RT) of similar size and depth was chosen in the darkest blue region on elastography (stiffest area) outside the cervix, posterior/lateral to the cervix over the ligament insertion. Lower the SR - softer the cervix. Two trained fetal medicine consultants performed the initial 57 cases until intra/inter-observer correlation was satisfactory. Delivery before 37 weeks (after 26 weeks), in which the process of labor has begun spontaneously, or labor was induced after PPROM-was considered as sPTD. SRs were assessed to determine how well they could predict sPTD independently or combined with cervical length.
UNASSIGNED: Out of 221 recruited,17 were lost to follow-up after 32 weeks; 204 were delivered in our hospital. Irrespective of the route of delivery, 71 (34.8%) had sPTD. Of the remaining 133, 106 delivered at term, and 27 underwent medically indicated PTD. Apart from multiple pregnancies, no other preterm-related risk factors (including CL < 2.5 cm) showed significant association with sPTD. Red CSE pattern around internal-os was associated with a significantly higher (54.5%) incidence of sPTD. CLs were similar (3.63 ± 0.67 vs. 3.63 ± 0.80, p = .981) whereas SRs in all three ROIs were significantly lower among sPTD group versus no sPTD group (IN:0.65 ± 0.29 vs 0.79 ± 0.30 p = .001, WN:0.34 ± 0.13 vs 0.39 ± 0.15, p = .013, AN:0.37 ± 0.16 vs 0.48 ± 0.26, p = .002, respectively). Using ROC curves, while CL was not predictive (AUROC 0.49, p = .81), SRs showed moderate predictive value toward sPTD with the best AUC of 0.624 (p = .003) at IN. Prediction was slightly better for early sPTD <32 weeks (AUC 0.653 p = 0.03). The best cutoff for SR at IN was 0.72, below which there was a moderate accuracy in predicting sPTD (sensitivity 52.11%, specificity 60.9%, PPV 41.57%, NPV 70.44%, diagnostic OR 1.69 and overall accuracy of 57.84%). A weak positive correlation is seen between IN and CL (Pearson\'s correlation R = 0.181). Multi-variable binary logistic regression analysis suggested that SRs at IN (Adjusted OR - 0.259 CI 0.079-0.850), AN (Adjusted OR 0.182 CI 0.034-0.963), Multiple Pregnancy (Adjusted OR 3.5 CI 1.51-8.13) and previous sPTD/PPROM (Adjusted OR 2.72 CI 0.97-7.61) independently predicted sPTD.
UNASSIGNED: TVS CSE performed better than CL as an independent predictive tool toward sPTD, although predictive efficacy was modest at best. Since technology is now available in high-end USG machines in tertiary care centers, we propose optimal utilization of CSE in LMICs to triage at-risk populations since low SRs are strongly associated with sPTD.
摘要：
经阴道超声引导下的宫颈应变弹性成像(CSE)现已在低收入和中等收入国家的三级转诊中心提供。TVS宫颈长度（CL）评估是常规使用。尽管如此，弹性成像不用于临床设置，尽管有足够的证据表明对sPTD（自发性早产）具有良好的预测价值。尚未在LMIC的高危人群中测试弹性成像的临床实用性，以预测sPTD。
■为了测试TVS-CSE在预测由于临床因素或由于子宫颈短而有sPTD风险的妊娠中期无症状妇女中sPTD的性能。
■在印度南部一家三级医院进行的前瞻性观察性研究。包括16至24周有一个或多个sPTD或CL<2.5cm临床危险因素的无症状孕妇。使用GEVolusonE-8超声机。CL测量后，在矢状视图的内部操作系统周围注意到弹性成像彩色编码。应变比（SR）是使用追踪方法在三个ROI（感兴趣区域）上计算的：矢状视图中的内部操作系统（IN），矢状视图中的整个子宫颈（WN），和内部操作系统在轴向视图（AN）。在宫颈外弹性成像上最暗的蓝色区域（最坚硬的区域）中选择相似大小和深度的参考组织（RT），后/外侧子宫颈在韧带插入。降低SR-使子宫颈变软。两名训练有素的胎儿医学顾问完成了最初的57例病例，直到观察者内/观察者间的相关性令人满意。分娩前37周（26周后），劳动过程自发开始，或在PPROM被认为是sPTD后引产。对SR进行了评估，以确定它们独立或结合宫颈长度预测sPTD的能力。
■在被招募的221人中，32周后17例失访；204例在我们医院分娩。无论交付途径如何，71例（34.8%）有sPTD。在任期内交付的其余133、106中，27人接受了医学指示的PTD。除了多胎妊娠,无其他早产相关危险因素(包括CL<2.5cm)与sPTD显著相关.内部操作系统周围的红色CSE模式与sPTD的发生率显着升高（54.5％）相关。CLs相似(3.63±0.67vs.3.63±0.80，p=.981），而sPTD组与无sPTD组相比，所有三个ROI的SR均显着降低（IN：0.65±0.29vs0.79±0.30p=.001，WN：0.34±0.13vs0.39±0.15，p=.013，AN：0.37±0.16vs0.48±0.26，p=.002）。使用ROC曲线，而CL不是预测性的(AUROC0.49，p=0.81)，SRs对sPTD显示中等预测值，在IN时最佳AUC为0.624（p=0.003）。早期sPTD<32周的预测略好（AUC0.653p=0.03）。在IN时，SR的最佳临界值为0.72，低于该临界值，预测sPTD的准确性中等（灵敏度为52.11%，特异性60.9%，PPV41.57%,净现值70.44%，诊断OR1.69，总体准确率为57.84%)。在IN和CL之间观察到微弱的正相关(皮尔逊相关性R=0.181)。多变量二元逻辑回归分析表明，在IN处的SRs(调整后OR-0.259CI0.079-0.850)，AN（调整后OR0.182CI0.034-0.963），多胎妊娠（校正OR3.5CI1.51-8.13）和先前的sPTD/PPROM（校正OR2.72CI0.97-7.61）独立预测了sPTD。
■作为sPTD的独立预测工具，TVSCSE比CL表现更好，尽管预测功效充其量是适度的。由于技术现在可以在三级护理中心的高端USG机器中使用，我们建议在LMICs中最佳利用CSE来分诊高危人群,因为低SRs与sPTD密切相关.
■为了测试TVS-CSE在预测由于临床因素或由于子宫颈短而有sPTD风险的妊娠中期无症状妇女中sPTD的性能。
■在印度南部一家三级医院进行的前瞻性观察性研究。包括16至24周有一个或多个sPTD或CL<2.5cm临床危险因素的无症状孕妇。使用GEVolusonE-8超声机。CL测量后，在矢状视图的内部操作系统周围注意到弹性成像彩色编码。应变比（SR）是使用追踪方法在三个ROI（感兴趣区域）上计算的：矢状视图中的内部操作系统（IN），矢状视图中的整个子宫颈（WN），和内部操作系统在轴向视图（AN）。在宫颈外弹性成像上最暗的蓝色区域（最坚硬的区域）中选择相似大小和深度的参考组织（RT），后/外侧子宫颈在韧带插入。降低SR-使子宫颈变软。两名训练有素的胎儿医学顾问完成了最初的57例病例，直到观察者内/观察者间的相关性令人满意。分娩前37周（26周后），劳动过程自发开始，或在PPROM被认为是sPTD后引产。对SR进行了评估，以确定它们独立或结合宫颈长度预测sPTD的能力。
■在被招募的221人中，32周后17例失访；204例在我们医院分娩。无论交付途径如何，71例（34.8%）有sPTD。在任期内交付的其余133、106中，27人接受了医学指示的PTD。除了多胎妊娠,无其他早产相关危险因素(包括CL<2.5cm)与sPTD显著相关.内部操作系统周围的红色CSE模式与sPTD的发生率显着升高（54.5％）相关。CLs相似(3.63±0.67vs.3.63±0.80，p=.981），而sPTD组与无sPTD组相比，所有三个ROI的SR均显着降低（IN：0.65±0.29vs0.79±0.30p=.001，WN：0.34±0.13vs0.39±0.15，p=.013，AN：0.37±0.16vs0.48±0.26，p=.002）。使用ROC曲线，而CL不是预测性的(AUROC0.49，p=0.81)，SRs对sPTD显示中等预测值，在IN时最佳AUC为0.624（p=0.003）。早期sPTD<32周的预测略好（AUC0.653p=0.03）。在IN时，SR的最佳临界值为0.72，低于该临界值，预测sPTD的准确性中等（灵敏度为52.11%，特异性60.9%，PPV41.57%,净现值70.44%，诊断OR1.69，总体准确率为57.84%)。在IN和CL之间观察到微弱的正相关(皮尔逊相关性R=0.181)。多变量二元逻辑回归分析表明，在IN处的SRs(调整后OR-0.259CI0.079-0.850)，AN（调整后OR0.182CI0.034-0.963），多胎妊娠（校正OR3.5CI1.51-8.13）和先前的sPTD/PPROM（校正OR2.72CI0.97-7.61）独立预测了sPTD。
■作为sPTD的独立预测工具，TVSCSE比CL表现更好，尽管预测功效充其量是适度的。由于技术现在可以在三级护理中心的高端USG机器中使用，我们建议在LMICs中最佳利用CSE来分诊高危人群,因为低SRs与sPTD密切相关.
