Cervical Elasticity Research Articles

Predicting cervical insufficiency in twin pregnancies using ultrasound cervical measurements and elastography.

Background: To evaluate the predictive effect of transvaginal ultrasound measurement of cervical length and cervical elasticity examination on cervical insufficiency in twin pregnancies. Methods: Data from twin pregnant women in our hospital were collected retrospectively, including relevant vaginal ultrasound parameters (e.g., cervical length, cervical elasticity score, and the strain value of each part of the cervix). We assessed the risk factors using receiver operating characteristic curve analysis to evaluate the predictive effect of each factor on the occurrence of cervical insufficiency. Results: A total of 284 pregnant women with twin pregnancies, including 142 with cervical insufficiency and 142 without cervical insufficiency, were included. Significant differences between the two groups were observed in the use of assisted reproductive technology, age, history of second-trimester miscarriage, etc. The cervical length of pregnant women with cervical insufficiency was significantly shorter at 22-24 weeks of gestation. Cervical length had the largest area under the receiver operating characteristic curve for predicting cervical insufficiency at that time. The area under the curve of cervical insufficiency predicted by the cervical elasticity score at 12-14 weeks of pregnancy was greater than that predicted by the cervical length at the same time, and the area under the curve of cervical insufficiency predicted by the elasticity score and pre-pregnancy body mass index during the same period was the largest. Conclusions: The cervical elasticity score at 12-14 weeks of gestation effectively predicted the occurrence of cervical insufficiency. The combination of the cervical elasticity score and pre-pregnancy body mass index predicted cervical insufficiency in women with twin pregnancies.

Relationship between endometriosis and uterine cervical elasticity assessed using ultrasound strain elastography.

Internal cervical os (ICO) stiffness is related to menstrual pain, a key symptom of endometriosis. The study evaluated whether women with endometriosis have a stiffer ICO than unaffected women. A retrospective cross-sectional analysis was conducted using prospectively collected data from women with and without endometriosis, spanning from June 2020 to September 2022. Endometriosis was diagnosed through clinical and ultrasound evaluations, with histological confirmation in a subset of participants. Strain elastography (SE) was employed to measure tissue elasticity in four cervical regions of interest: the ICO and the anterior, posterior, and middle cervical compartments (ACC, PCC, and MCC, respectively). Tissue elasticity was quantified using a color-based scoring system ranging from 0.1 (blue, indicating less elasticity) to 3.0 (red, indicating greater elasticity). Overall, 287 women were included, with 157 diagnosed with endometriosis and 130 controls. On SE, women with endometriosis exhibited a lower color score (mean±standard deviation), indicating lower elasticity, for the ICO (0.56±0.28 vs. 0.70±0.26, P=0.001) and PCC (0.69±0.30 vs. 0.80±0.27, P=0.002). Additionally, they had a lower ICO/MCC ratio (0.45±0.28 vs. 0.60±0.32, P=0.001) and ICO/ACC ratio (0.68±0.42 vs. 0.85±0.39, P=0.001). Multiple logistic regression analysis revealed that endometriosis was associated with the ICO color score (odds ratio, 0.053; 95% confidence interval, 0.014 to 0.202; R2=0.358; P=0.001), even after adjusting for confounding factors like the presence of myomas (P=0.040) and the use of hormonal therapy (P=0.001). The results were corroborated in women with histologically confirmed endometriosis (n=71). The findings suggest a potential relationship between a stiffer ICO and endometriosis.

CELASTO (Cervical ELASTOgraphy) pilot study — the use of cervical elastography during pregnancy

BACKGROUND: Ultrasound assessment of cervical length is an integral part of a comprehensive examination during pregnancy, but it does not provide a complete picture of structural changes in the cervix. The use of E-Cervix elastography is a promising method to assess cervical remodeling throughout the gestation period. AIM: The aim of this study was to evaluate the possibility of using automated cervical elastography in clinical practice to analyze the main parameters of cervical elasticity and hardness in pregnancy. MATERIALS AND METHODS: This prospective pilot study included 136 patients with singleton pregnancies at gestational ages ranging from 7+0 to 41+0 weeks. Cervical elastography was performed using E-Cervix software of the W10 diagnostic ultrasound system (Samsung Medison Co., Ltd., South Korea) with evaluation of quantitative parameters such as hardness ratio, elasticity contrast index, internal os, external os. RESULTS: Correlation analysis showed that hardness ratio decreased with increasing gestational age (ρ = −0.439) and decreasing cervical length (ρ = 0.408; p 0.001). In the group of patients with cervical length less than 25 mm, there was a decrease in hardness ratio compared to the control group (48.0 vs. 63.8%, respectively; p 0.001). The elasticity contrast index score, which reflects cervical tissue heterogeneity, increased with gestational age and cervical shortening (ρ = 0.368 and −0.450, respectively), the parameter being higher in patients with cervical length less than 25 mm [4.73 (IQR 4.21–5.90); p 0.001]. The increase in internal os and external os with gestational age (ρ = 0.433 and ρ = 0.365, respectively; p 0.001) indicates softening of the cervix and is accompanied by its shortening. CONCLUSIONS: Results indicate decreased hardness and increased elasticity of the cervix with increasing gestational age and decreased cervical length. E-Cervix technology allows for assessing structural changes in the cervix throughout pregnancy, starting from early gestation.

Cervical elastography in predicting spontaneous preterm birth in singleton pregnancy with a short cervix receiving progesterone treatment at 18 to 24 weeks’ gestation

Background A short cervix in the second trimester is known to increase the risk of preterm birth, which can be reduced with the administration of vaginal progesterone. However, some studies have suggested that a significant number of cases still experience preterm birth despite progesterone treatment. Objective This study was aimed to investigate the potential value of transvaginal cervical elasticity measured by E-Cervix as a predictor for spontaneous preterm birth (sPTB) in singleton pregnancies receiving progesterone treatment for a short cervix (CL ≤ 2.5 cm) diagnosed at 18 to 24 weeks’ gestation. Study design This prospective study was conducted at a single center premature high-risk clinic from January 2020 to July 2022. Singleton pregnancies with a short cervix at 18 to 24 weeks’ gestation were enrolled. Cervical elastography using E-Cervix was performed, and maternal and neonatal demographic characteristics, cervical length (CL), elasticity contrast index (ECI), cervical hardness ratio, mean internal os strain (IOS), and mean external os strain (EOS) were compared before and after progesterone treatment in sPTB and term birth groups. Multivariate logistic regression was used to analyze the association between elasticity parameters and spontaneous preterm birth. The screening performance of CL and optimal cervical elasticity parameters in predicting sPTB was evaluated using receiver-operating characteristic (ROC) curve analysis. Results A total of 228 singleton pregnant women were included in the study, among which 26 (11.4%) had sPTB. There were no significant differences in maternal characteristics and gestational age at enrollment between women with and without sPTB. At the start of progesterone treatment, there were no significant differences in cervical elasticity parameters between the two groups. After two weeks of progesterone treatment, women who had sPTB showed significantly higher levels of ECI, IOS, EOS (p = 0.0108, 0.0001, 0.016), and lower hardness ratio (p = 0.011) compared to those who had a full-term birth. Cervical length did not show significant differences between the two groups, regardless of whether progesterone treatment was administered before or after. Among the post-treatment cervical elasticity parameters, IOS and EOS were associated with a 3.38-fold and 2.29-fold increase in the risk of sPTB before 37 weeks (p = 0.032, 0.047, respectively). The AUROC of the combined model including CL, IOS, and EOS (0.761, 95% CI0.589–0.833) was significantly higher than the AUROC of CL alone (0.618, 95% CI 0.359–0.876). At a fixed false-positive of 13%, the addition of IOS and EOS in the CL model increased sensitivity from 34.6% to 57.6%, PPV from 25.7% to 36.5%, and NPV from 91.1% to 94.1%. Conclusion When assessing the risk of sPTB in singleton pregnancies with a short cervix receiving progesterone therapy, relying solely on cervical length is insufficient. It is crucial to also evaluate cervical stiffness, particularly the strain of the internal and external os, using cervical elastography.

Quantitative Analysis of the Impact of Different Delivery Modes on Cervical Elasticity Based on Real-time Shear Wave Imaging Technology and Artificial Intelligence.

Real-time shear wave elastography (SWE) has emerged as a useful imaging modality for detecting the lesion location of various diseases, including cervical diseases. In this paper, the SWE was used to quantitatively determine the tissue hardness of the internal and external orifice of the cervix (IOC & EOC) and to relatively objectively analyze the impact of different production methods on the hardness of the cervical tissue. A total of 48 patients were selected, and they were divided into three groups according to different production methods: control group (16 cases), cesarean section group (16 cases), and spontaneous delivery group (16 cases). Artificial intelligence has also been incorporated into this work. A deep flexible neural tree model and a new set of FNT models were proposed to assist in classifying cervical physical data in different states. The physical data was extracted as the features, and the different states were considered as category labels. There was no statistically significant difference in the elasticity of the IOC and the EOC between the groups. However, the difference in the elasticity of the IOC and the EOC within each group was statistically significant. The classification results corresponded with the results of the statistical analysis. The hardness of the EOC is generally lower than that of the IOC, and there was no significant difference in hardness between the IOC and the EOC in the three groups. There is no significant difference in the cervical elasticity hardness between different delivery modes.

Quantification of Cervical Elasticity During Pregnancy Based on Transvaginal Ultrasound Imaging and Stress Measurement.

To overcome these limitations, we develop a quantitative cervical elastography system by adding a stress sensor to a clinically used transvaginal ultrasound imaging system. We record the cervical deformation in B-mode images and measure the probe-surface stress through the sensor. Then we quantify the strain using a customized algorithm and estimate the cervical Young's modulus through stress-strain linear regression. In phantom experiments, we demonstrate the system's high accuracy (alignment with the quasi-static compression method, p-value = 0.369 > 0.05), robustness (alignment between 60°- and 90°-contact measurements, p-value = 0.638 > 0.05), repeatability (consistency of single sonographers' measurements, coefficient of variation < 0.06), and reproducibility (alignment between two sonographers' measurements, Pearson correlation coefficient = 0.981). Applying it to pregnant participants, we observe significant cervical softening (p-value < 0.001): Young's modulus decreases 3.95% weekly and its geometric mean value during the first (11 to 13 weeks), second, and third trimesters are 13.07 kPa, 7.59 kPa, and 4.40 kPa, respectively. The proposed system is accurate, robust, and safe, and enables longitudinal and inter-examiner comparisons. The system applies to different ultrasound machines with minor software updates, which allows for studies of cervical softening patterns in pregnancy for larger populations, facilitating insights into conditions such as preterm birth.

Changes in cervical elastography, cervical length and endocervical canal width after cerclage for cervical insufficiency: an observational ultrasound study

BackgroundWe previously demonstrated that pregnant women with a history of cervical insufficiency had a softer anterior cervical lip, shorter cervical length and wider endocervical canal in the first trimester. The aim of this study was to investigate changes in cervical elastography, cervical length, and endocervical canal width in the second trimester after cerclage, and further discuss whether these ultrasound parameters are predictive of preterm delivery.MethodsThis was a secondary analysis of cervical changes in singleton pregnancies after cerclage from January 2016 to June 2018. Cervical elastography, cervical length, and endocervical canal width were measured during the second trimester in the cervical insufficiency group and control group without cervical insufficiency. Strain elastography under transvaginal ultrasound was used to assess cervical stiffness and presented as percentage (strain rate).ResultsAmong the 339 pregnant women enrolled, 24 had a history of cervical insufficiency and underwent cerclage. Both anterior and posterior cervical lips were significantly softer in the cervical insufficiency group even though they received cerclage (anterior strain rate: 0.18 ± 0.06% vs. 0.13 ± 0.04%; P = 0.001; posterior strain rate: 0.11 ± 0.03% vs. 0.09 ± 0.04%; P = 0.017). Cervical length was also shorter in the cervical insufficiency group (36.3 ± 3.6 mm vs. 38.3 ± 4.6 mm; P = 0.047). However, there was no significant difference in endocervical canal width between the two groups (5.4 ± 0.7 mm vs. 5.6 ± 0.7 mm; P = 0.159). Multivariate logistic regression analysis also revealed significant differences in anterior cervical lip strain rate (adjusted odds ratio [OR], 7.32, 95% confidence interval [CI], 1.70-31.41; P = 0.007), posterior cervical lip strain rate (adjusted OR, 5.22, 95% CI, 1.42–19.18; P = 0.013), and cervical length (adjusted OR, 3.17, 95% CI,1.08–9.29; P = 0.035). Among the four ultrasound parameters, softer anterior cervical lip (P = 0.024) and shorter cervical length (P < 0.001) were significantly related to preterm delivery.ConclusionsCervical cerclage can prevent widening of the endocervical canal, but not improve cervical elasticity or cervical length. Measuring anterior cervical elastography and cervical length may be valuable to predict preterm delivery.

Cerebral hemodynamics affected by cervical elasticity and cardiac pulse wave propagation

Cerebral hemodynamics affected by cervical elasticity and cardiac pulse wave propagation

Quantification of cervical stiffness changes in single and twin pregnancies using the E-Cervix technique

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.

Shear wave elastography: the relationship of the cervical stiffness with gestational age and cervical length- a feasibility study

Objectives To standardize the measurement of shear wave elastography for assessment of cervical stiffness and its relationship with gestational age and cervical length. Methods A prospective cross-sectional study was conducted from September 2017 to March 2019. Data from 125 unselected women (at 11–13 + 6, 18–22 and 24–28 weeks’ gestation) and 55 high-risk women were analyzed for the study. Six regions of interest were evaluated for cervical elastography in the mid-sagittal position by transvaginal ultrasound. Statistical analyses were performed using R statistical language in R-studio. Delivery outcomes were recorded for each patient. Results The shear wave elastography was feasible with good intraoperator and interoperator reproducibility. The endocervical canal and anterior lip internal position had the highest reproducibility (ICC-0.82, 0.75). Shear wave speed was significantly higher in all internal os regions than the external os. There was a statistically significant negative linear relationship of shear wave speed with the gestational age. There was a weak positive relationship between shear wave speed and cervical length. There was no difference between pregnancies with and without spontaneous preterm delivery in shear wave speed measurements and cervical length, although numbers were small for statistical analysis. The internal os of the large loop excision of the transformation zone group was stiffer than the normal population. Conclusion Cervical elastography is feasible and effectively evaluates the tensile properties of the cervix during pregnancy. The most reproducible measurements were obtained at the anterior lip of the internal cervical os. Combining evaluation of cervical elasticity and length might further improve the identification of women at risk of preterm delivery. Currently, technical issues hinder the practical application of shear wave elastography in the clinical setting and require further research and development of the imaging modality.

The Utility of Myometrial and Cervical Ultrasound Shear Wave Elastography in the Diagnosis of Ectopic Pregnancy

We aimed to assess the potential utility of myometrial and cervical elasticity measurement in the diagnosis of ectopic pregnancy (EP), which could facilitate the diagnosis process. Myometrial and cervical elasticity values were measured in women with EP, women with early intrauterine pregnancy (IP) and non-pregnant women. Transabdominal point shear wave elastography (pSWE) was used for elasticity measurements. A reliability study was performed in 20 patients of the non-pregnant group. Cervical pSWE showed poor reliability and high measurement failure rate; thus, we excluded cervical elasticity assessment from the study. In this study, 32 women with EP, 28 women with early IP and 38 non-pregnant women were enrolled for myometrial elasticity assessment by pSWE. Myometrial elasticity values were statistically significantly lower in EP (8.31 kPa [5.1–27]) and early IP (8.83 kPa [4.5–46.2]) groups than in non-pregnant women (14.85 kPa [5.1–28]) (p = 0.003). However, myometrial pSWE results were not significantly different between EP and early IP groups. In light of this data, quantitative assessment of the uterus elasticity using pSWE does not seem to be an adequate diagnostic method for EP.

Correlation between cervical elastography parameters and time of the first stage of labor in late pregnancy by transvaginal ultrasound

Objective To investigate the correlations between the labor process and the elastography parameters, and to explore the correlations among the elastography parameters. Methods A total of 48 pregnant women in the late periods of pregnancy in Beijing Hospital from November 10, 2018 to January 30, 2019 were recruited prospectively. Elastography was performed to measure several elastographic parameters including the cervical length (CL), elasticity contrast index (ECI), hardness ratio (HR), internal orifice uterus(IOS) and external orifice uterus(EOS). They were followed up to delivery, and were divided into normal group and prolonged group according to the time duration of the first stage of labor. The correlation between the parameters and the time duration of the first stage of labor, as well as the relationships among the parameters were evaluated. Results Among the 48 pregnant women, 35 cases were delivered by the vagina, 13 by cesarean section, 4 of whom were due to the prolongation of the first stage of labor and the other 9 cases for other reasons. The values of the CL and HR in normal group were significantly lower than that in prolonged group (P=0.004, 0.02). The ECI in the normal group was significantly higher than that in the prolonged group (P=0.046). Both the IOS and EOS in the normal group were higher than those in prolonged group without no significant difference(P>0.05). For the 35 women who underwent cervical elasticity assessment before labor and finally delivered vaginally, the duration of the first stage of labor was negatively correlated with cervical ECI (r=-0.415, P 0.05). Conclusions The ECI of cervical tissue measured by cervical elastography can be used to semi-quantitatively evaluate the maturity of the cervix, it has potential value in predicting the labor duration and guiding clinical decision-making. Key words: Ultrasonography, transvaginal; Elastography; Time of the first labor; Late pregnancy

Cervical Characterization with Tactile-Ultrasound Probe.

Background:Premature cervical softening and shortening may be considered an early mechanical failure that predisposes to preterm birth. Preliminary clinical studies demonstrate that cervical elastography may be able to quantify this phenomenon and predict spontaneous preterm delivery.Objective:To explore a new approach for cervix elasticity and length measurements with tactile-ultrasound probe.Methods:Cervix probe has tactile array and ultrasound transducer designed to apply controllable load to cervix and acquire stress-strain data for calculation of cervical elasticity (Young’s modulus) and cervical length for four cervix sectors. Average values, standard deviations, intraclass correlation coefficients and the 95% limits of agreement (Bland-Altman plots) were estimated.Results:Ten non-pregnant and ten pregnant women were examined with the probe. The study with non-pregnant women demonstrated a reliable acquisition of the tactile signals. The ultrasound signals had a prolonged appearance; identification of the internal os of the cervix in these signals was not reliable. The study with pregnant women with the gestational age of 25.4 ± 2.3 weeks demonstrated reliable data acquisition with real-time visualization of the ultrasound signals. Average values for cervical elasticity and standard deviations of 19.7 ± 15.4 kPa and length of 30.7 ± 6.6 mm were calculated based on two measurements per 4 sectors. Measurement repeatability calculated as intraclass correlation coefficients between two measurements at the same cervix sector on pregnant women was found to be 0.97 for cervical elasticity and 0.93 for the cervical length. The 95% limits of agreement of 1) cervical elasticity were from −22.4% to +14.9%, and 2) cervical length from −13.3% to +16.5%.Conclusions:This study demonstrated clinically acceptable measurement performance and reproducibility. The availability of stress-strain data allowed the computation of cervical elasticity and length. This approach has the potential to provide cervical markers to predict spontaneous preterm delivery.

Quantitative cervical elastography: a new approach of cervical insufficiency prediction.

To establish methodological criteria for the clinical application of E-cervix technology in non-pregnant women, evaluate cervical differences between non-pregnant CI patients and normal women, and explore the predictive value of E-cervix for CI in non-pregnant women. In all, 46 non-pregnant women with CI and 46 non-pregnant women with full-term pregnancy experiencewere included. Elastic parameters (HR, IOS, EOS, IOS/EOS, CL) of the cervix were measured by transvaginal examination with a mid-sagittal section as the ROI, followed by examination of the whole cervix. The pressure of the probe on the cervix was divided into three levels. The elastic data of three consecutive images were separately obtained by two doctors for three pressure levels. Image stability and the effects of pressure were evaluated and the repeatability of the measurements was tested. In the case and control groups, cervical elasticity images were selectedby standardized operation methods. Differences in the parameters between the two groups were determined and the diagnostic efficiency of each parameter was analyzed. The HR, IOS, and EOS showed significant differences when measured on different sequential images obtained by continuous mapping (p < 0.05). The elastic parameters obtained from the first and last two images were significantly different (p < 0.05) and there were no significant differences between the elastic parameters obtained from the last two images (p > 0.05). The HR, IOS, EOS, and IOS/EOS showed significant differences among the pressure levels (p < 0.05), while the IOS showed a significant difference only between grades 0 and 2 (p < 0.05). E-cervix showed good repeatability within and among operators. The elastic parameters obtained by E-cervix in the CI group and control group were significantly different. ROC curve analysis showed that the HR was the most sensitive index for diagnosing CI. In E-cervix data acquisition, the first image should be excluded and the probe should not put pressure on the cervix. E-cervix has good retest and inter-observer reliability. Compared with normal women, CI patients showed a relatively softer and shorter cervix. E-cervix can be used as an important diagnostic tool for assessing cervical strain.

Evaluation of Cervical Elastography for Prediction of Spontaneous Preterm Birth in Low-Risk Women: A Prospective Study.

The aim of this study was to determine whether cervical elastographic parameters in addition to cervical length (CL) during the 3 trimesters of pregnancy would be predictive of spontaneous preterm birth (sPTB) among low-risk women. This work was a prospective nested case-control study evaluating cervical elastographic parameters and CL in low-risk women during the 3 trimesters of pregnancy. A binary logistic regression analysis was used to calculate significant covariates for prediction of sPTB. The area under the curve of the prediction model was calculated by using a receiver operating characteristic curve. There were 286 women (26 cases and 260 controls) included in the analysis. The parameters of cervical elasticity became softened and heterogeneous during the 3 trimesters of pregnancy in both women with and without sPTB. The differences in the mean strain value at the internal os of the cervix (IOS), ratio (strain ratio of the internal os to the external os) during the second trimester and the IOS during the third trimester between the groups had statistical significance (P < .01; P = .01; P < .01, respectively). The CL had no association with sPTB during the 3 trimesters. The IOS during the second trimester was a better predictor of sPTB, with an area under the curve of 0.730, and sensitivity was 72.73%. We observed multiple elastographic parameters and demonstrated the physiologic changes in the cervix during the 3 trimesters of pregnancy. Furthermore, we found that the IOS during the second trimester can be helpful in predicting sPTB. However, the CL had no association with sPTB during the 3 trimesters of pregnancy.

In Vivo Measurement of Cervical Elasticity on Pregnant Women by Torsional Wave Technique: A Preliminary Study.

A torsional wave (TW) sensor prototype was employed to quantify stiffness of the cervix in pregnant women. A cross-sectional study in a total of 18 women between 16 weeks and 35 weeks + 5 days of gestation was performed. The potential of TW technique to assess cervical ripening was evaluated by the measurement of stiffness related to gestational age and cervical length. Statistically significant correlations were found between cervical stiffness and gestational age (, , using 1 kHz waves and , , using 1.5 kHz waves). A uniform decrease in stiffness of the cervical tissue was confirmed to happen during the complete gestation. There was no significant correlation between stiffness and cervical length. A stronger association between gestational age and cervical stiffness was found compared to gestational age and cervical length correlation. As a conclusion, TW technique is a feasible approach to objectively quantify the decrease of cervical stiffness related to gestational age. Further research is required to evaluate the application of TW technique in obstetric evaluations, such as prediction of preterm delivery and labor induction failure.

Cervical elasticity during pregnancy: current state of the problem

Uterine cervix undergoes various changes throughout the pregnancy, which are characterized by the general term “remodeling”. In particular, this process includes changes of the length (shortening) and consistency (softening) of uterine cervix. The latter from the clinical point of view is important not only for observation of pregnant women with normal course of pregnancy but also for predicting such states as an outcome of labor induction or preterm delivery. Traditionally, cervical elasticity has been estimated through digital examination and Bishop score, however, currently there are available imaging techniques, which are more objective and precise. Amongst these methods, elastography plays a special role. Elastography allows measuring the capacity of tissues to deform. The softer the tissues, the higher mentioned capacity under the applied pressure. Currently there are various methods of elastography, starting from real-time elastography, when the capacity to be deformed is registered under the influence of physiologic movements or minimal manual pressure, to shear wave elastography, when the velocity of propagation of shear waves is measured. Although there are number of methods of elastography and perspectives of their use in obstetric practice, at the present time there is no consensus on standardization of these methods. In the cervical elastography this task is even more complicated, because there is no reference tissue to be compared with, especially this is true for strain elastography. The aim of this study was comparative analysis of methods estimating cervical elasticity and underlining current problems from the clinical point of view.

OP10.03: Gestational age‐related changes in uterine cervical elasticity in normal pregnancy at 12–35 weeks' gestation evaluated using shear wave elastography

To analyse the gestational age-related changes in elasticity of the normal uterine cervix at 12-35 weeks' gestation using shear wave elastography. The subjects consisted of 417 cases of normal singleton pregnancy at 12-35 weeks' gestation, cared for in our hospital from July 2016 to January 2017. The shear wave speed (SWS) of the cervix was measured using transvaginal ultrasonography (Aplio 500, Toshiba). On the sagittal section, sampling points were placed on the anterior (A), posterior (P), and cervical canal (C) regions of the internal and external os (IO/EO). After dividing the observational period into 6 groups at 4-week interval, the following parameters were analysed: 1) the changes in SWS at each point with advancing gestation; 2) comparison of SWSs at both the IO and EO for A, P and C. Statistical analyses were made using piecewise linear regression analysis, the Mann-Whitney U-test, the Kruskal-Wallis and the Wilcoxon test as post-hoc test. Significance was set at P<0.05. The SWSs of posterior at the IO decreased in piecewise linear regression, with a critical point at 20 weeks, whereas the SWSs of the remaining points decreased linearly. At the IO, the SWSs of P were higher than those of A and C at all age-groups. The SWSs of P and A at the IO were higher than those at the EO at all age-groups. The SWSs of C at the IO were higher than those at the EO before 20-23 weeks, respectively, however, the SWSs were not different between the points thereafter. The SWSs of A at the IO were higher than those at the EO before 28-31 weeks, respectively, however, the SWSs were not different between the points thereafter. The posterior cervix at the internal os, the hardest point of the cervix at all age-groups, softened with advancing gestation, while the endocervix was harder than the ectocervix before 35 weeks, showing a physiological cervical maturation with advancing gestation.

Ultrasound elastography capabilities in studying uterine cerviх state in pregnant women of high-risk group in the first trimester of pregnancy

Aim. To study capabilities of quantitative elastographic study to assess the elasticity of the uterine cervix in women with a fetal chromosomal abnormality in the first trimester of pregnancy.Methods. 230 pregnant women of high-risk group at 11-13.6 weeks of pregnancy (parietal-coccygeal length 45-84 mm) were included in this study. The first group consisted of 213 women without fetal pathology. The second group included 17 women, in whose fetuses different chromosomal abnormalities were detected. In ultrasound examination of pregnant women in the I trimester of pregnancy, in addition to standard methods of examination, quantitative cervical elastography was performed.Results. According to results of quantitative elastography in 14 (82.35%) out of 17 pregnant women (second group) one or another degree of the cervical tissue softening was found, and 3 (17.64%) pregnant women with fetal chromosomal pathology had stiff cervix (all 3 cases with Down syndrome). In the control group in 10 (4.7%) of 213 pregnant women relatively soft cervix was identified, and in 203 (95.3%) women cervical density was higher than the myometrial density. A statistically significant difference between the indices of SWE-Ratio in groups was revealed. Quantitative elastography, as a diagnostic test predicting the risk of miscarriage due to chromosomal abnormalities, has a high sensitivity (84.38%) and even higher specificity (95.26%) of negative predictive value 97.57%.Conclusion. Quantitative elastography reveals a significant decrease in the cervical elasticity (softening) in pregnant women with fetal chromosomal abnormality in the I trimester of pregnancy, which allows us to recommend this method of ultrasound examination as an additional marker for early diagnosis of miscarriage due to fetal chromosomal abnormality.

In Vivo Evaluation of Cervical Stiffness Evolution during Induced Ripening Using Shear Wave Elastography, Histology and 2 Photon Excitation Microscopy: Insight from an Animal Model.

Prematurity affects 11% of the births and is the main cause of infant mortality. On the opposite case, the failure of induction of parturition in the case of delayed spontaneous birth is associated with fetal suffering. Both conditions are associated with precocious and/or delayed cervical ripening. Quantitative and objective information about the temporal evolution of the cervical ripening may provide a complementary method to identify cases at risk of preterm delivery and to assess the likelihood of successful induction of labour. In this study, the cervical stiffness was measured in vivo in pregnant sheep by using Shear Wave Elastography (SWE). This technique assesses the stiffness of tissue through the measurement of shear waves speed (SWS). In the present study, 9 pregnant ewes were used. Cervical ripening was induced at 127 days of pregnancy (term: 145 days) by dexamethasone injection in 5 animals, while 4 animals were used as control. Elastographic images of the cervix were obtained by two independent operators every 4 hours during 24 hours after injection to monitor the cervical maturation induced by the dexamethasone. Based on the measurements of SWS during vaginal ultrasound examination, the stiffness in the second ring of the cervix was quantified over a circular region of interest of 5 mm diameter. SWS was found to decrease significantly in the first 4–8 hours after dexamethasone compared to controls, which was associated with cervical ripening induced by dexamethasone (from 1.779 m/s ± 0.548 m/s, p < 0.0005, to 1.291 m/s ± 0.516 m/s, p < 0.000). Consequently a drop in the cervical elasticity was quantified too (from 9.5 kPa ± 0.9 kPa, p < 0.0005, to 5.0 kPa ± 0.8 kPa, p < 0.000). Moreover, SWE measurements were highly reproducible between both operators at all times. Cervical ripening induced by dexamethasone was confirmed by the significant increase in maternal plasma Prostaglandin E2 (PGE2), as evidenced by the assay of its metabolite PGEM. Histological analyses and two-photon excitation microscopy, combining both Second Harmonic Generation (SHG) and Two-photon Fluorescence microscopy (2PF) contrasts, were used to investigate, at the microscopic scale, the structure of cervical tissue. Results show that both collagen and 2PF-active fibrillar structures could be closely related to the mechanical properties of cervical tissue that are perceptible in elastography. In conclusion, SWE may be a valuable method to objectively quantify the cervical stiffness and as a complementary diagnostic tool for preterm birth and for labour induction success.