Contractions of the lower uterine segment during transvaginal ultrasound cervical length: incidence, significance, proper measurement, and management.

An accurate transvaginal ultrasound cervical length is paramount to obtain the best prediction for preterm birth. Transvaginal ultrasound cervical length should be optimally obtained when a lower uterine segment contraction is not seen. For universal transvaginal ultrasound cervical length screening at approximately 20 weeks of gestation, the options are to do the transvaginal ultrasound soon after bladder void (lower uterine segment contractions present in 16%-43% of this approach) or to wait until the end of the anatomy scan (ideally within 30 minutes after bladder voiding) to decrease the chance of a lower uterine segment contraction. If the lower uterine segment contraction persists even after waiting up to 20 minutes or more, only the true transvaginal ultrasound cervical length should be reported. In particular, in patients with a previous spontaneous preterm birth, if the lower uterine segment contraction persists, the transvaginal ultrasound cervical length can be repeated in ≤7 days even in the presence of a normal (>25 mm) cervical length. Similar to a blood pressure cuff that must be of the right size for proper blood pressure measurement and a glucometer that must be properly calibrated, screening with transvaginal ultrasound cervical length should only be performed following a proper and standardized technique, including avoiding as much as feasible the presence of lower uterine segment contractions.

Cervical assessment certification and its impact on performance quality in the context of universal cervical screening.

OBJECTIVE: To assess the impact of the introduction of universal transvaginal cervical screening and certification on the quality of cervical length ultrasound images. METHODS: The present study included a retrospective cohort of singleton pregnancies that underwent transvaginal cervical length measurement at the anatomical scan (180/7 and 236/7 weeks) before (period A, 2015-2017) and after (period B, 2017-2019) the introduction of universal transvaginal cervical length screening. Independent observers blindly evaluated the images obtained for cervical length using a qualitative scoring method based on five criteria, according to the Fetal Medicine Foundation. RESULTS: In all, 6013 patients met the inclusion criteria, 3333 in period A and 2680 in period B. Maternal characteristics and risk factors for preterm birth were similar between the two periods. The acceptance of transvaginal cervical length measurement in period B was 95.5% in the overall cohort and 100% in the subgroup of high-risk patients. The quality score was significantly higher in period B than in period A. Among the image quality criteria, the anterior/posterior ratio, the correct magnification of the images, and the calipers' placement contributed significantly to the improved quality score in period B. Most of the sonographers performed better in period B, irrespective of the years of experience, but certificate holders obtained higher scores than non-certified sonographers, particularly those in mid-career. The identification of short cervix was significantly higher in period B than in period A. CONCLUSION: The implementation of universal transvaginal cervical length screening and the certification process are associated with improved quality of cervical length images, even among expert sonographers and in the presence of anatomical pitfalls.

Assessment of utero-cervical angle and cervical length as predictors for threatened preterm delivery in singleton pregnancies.

OBJECTIVES: The aim of this study was to evaluate the relationship between the cervix and the threat of preterm labor in singleton pregnancies between gestational weeks less than 37 and greater than 37 weeks in correlation with utero-cervical angle (UCA) and cervical length (CL) measurements. MATERIALS AND METHODS: We conducted a prospective cohort study with UCA and CL measurements in patients with threatened preterm labor (TPL). Primary outcome was differences in UCA and CL measurements in relationship to maternal characteristics and perinatal outcome between groups. Secondary outcome evaluated measurement results and influencing factors for delivery within 7 days, between 1 and 4 weeks and beyond 4 weeks. RESULTS: Overall 152 patients were divided into as study/preterm group (<37 weeks; n = 56) and the control/term group (≥37 weeks; n = 96). Mean gestational age at admission was similar in both groups (30.98 ± 2.83 vs. 30.36 ± 2.63 weeks, p = 0.149) with similar CL (33.9 ± 6.34 vs. 32.02 ± 8.88 mm, p = 0.132), but wider UCA in the preterm group (81.65 ± 16.81° vs. 99.21 ± 22.33°, p < 0.001). Multivariate logistic regression analysis for preterm delivery was significant for nulliparity and UCA measurement. The factor for delivering before 37 gestational weeks within 7 days was the gestational week at admission (p = 0.046). UCA and CL measurements were statistically significant for distinguishing patients for delivery within 7 days and beyond 4 weeks (p = 0.001 for CL and p = 0.0001 for UCA). NPV was found 92.5, 92.2, and 92.3 for UCA >105°, CL ≤30 mm, and Bishop score >3, respectively. CONCLUSION: Combined measurement of TV UCA and CL represents stronger predictors for sPTB ultrasonographically, demonstrating the uterocervical sub-segment maturation before the active onset of labor.

Estimates of avoided costs attributed to a short cervix screening program to prevent preterm birth from the perspective of the Unified Health System (SUS).

OBJECTIVE: To perform an economic cost analysis of the implementation of a short cervix screening program to reduce preterm birth in singleton pregnancies in a short-term time horizon. METHODS: We performed a cost-benefit economic analysis using the P5 trial database, a randomized multicenter clinical trial for prevention of preterm birth. Data collection was conducted from July 2015 to March 2019 in 17 different Brazilian hospitals. We conducted a cost analysis for universal cervical screening in singleton pregnancies between 18 weeks and 22 weeks plus 6 days. In subjects with a cervical length ≤ 25 mm, the analysis incorporated the costs of administering 200 mg/day of vaginal progesterone prophylactically until 36 weeks gestation. These findings were subsequently compared with the economic implications of forgoing cervical screening. The time horizon comprised from birth to 10 weeks postpartum. The outcome was measured monetarily in Brazilian real (R$) from the perspective of the Unified Health System. RESULTS: Among 7,844 women, 6.67% (523) had a cervix ≤ 25 mm. The cost of screening with transvaginal ultrasound and vaginal progesterone for prevention of births with < 34 weeks was estimated at R$ 383,711.36, while non-screening generated an estimated additional cost of R$ 446,501.69 (related to the 29 non-screened preterm deliveries). Thus, screening and prophylaxis would generate a final cost reduction of R$ 62,790.33, constituting a possible cost-benefit strategy. CONCLUSION: Universal short cervix screening for preterm birth has lower costs compared to non-screening within a short-term time horizon, which suggests an interesting benefit-cost ratio. Future studies should consider the cost-effectiveness of prophylactic treatment using sensitivity analyses in different scenarios within the Brazilian health system, as well as analyses that consider the long-term costs associated with preterm births, to robustly justify the implementation of a short cervix screening program.

Assessment of cervical softening and the prediction of preterm birth (STIPP): protocol for a prospective cohort study.

INTRODUCTION: Preterm birth (PTB) is among the leading causes of perinatal and childhood morbidity and mortality. Therefore, accurate identification of pregnant women at high risk of PTB is key to enable obstetric healthcare professionals to apply interventions that improve perinatal and childhood outcomes. Serial transvaginal cervical length measurement is used to screen asymptomatic pregnant women with a history of PTB and identify those at high risk for a recurrent PTB. Cervical length measurement, fetal fibronectin test or a combination of both can be used to identify women at high risk of PTB presenting with symptoms of threatened PTB. The predictive capacity of these methods can be improved. Cervical softening is a precursor of cervical shortening, effacement and dilatation and could be a new marker to identify women a high risk of PTB. However, the predictive value of cervical softening to predict spontaneous PTB still needs to be determined. METHODS AND ANALYSIS: This is a single-centre, prospective cohort study, conducted at the Amsterdam University Medical Centers in the Netherlands. Cervical softening will be investigated with a non-invasive CE-marked device called the Pregnolia System. This device has been developed to evaluate consistency of the cervix based on tissue elasticity. Two different cohorts will be investigated. The first cohort includes women with a history of spontaneous PTB <34 weeks. These women undergo biweekly measurements between 14 and 24 weeks of gestation. The second cohort includes women with symptoms of threatened PTB. These women will receive the measurement once at presentation between 24 and 34 weeks of gestation. The primary outcome is spontaneous PTB before 34 weeks for women with a history of PTB and delivery within 7 days for women with threatened PTB. The minimum sample size required to analyse the primary outcome is 227 women in the cohort of women with a history of PTB and 163 women in the cohort of women with symptoms of threatened PTB. Once this number is achieved, the study will be continued to investigate secondary objectives. ETHICS AND DISSEMINATION: The study is approved by the Medical Ethics Committee of Amsterdam UMC (METC2022.0226). All patients will give oral and written informed consent prior to study entry. Results will be disseminated via a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT05477381.

Ultrasound assessment of cervical status compared to the Bishop score - predicting the success of labor induction using a machine learning-based model.

OBJECTIVE: The main aim of this study was to develop a machine-learning-based model for predicting the success of labor induction (IOL). To that end, the clinical and ultrasound parameters that affect the successfulness of labor induction were assessed. Then, a new ultrasound scoring system (USS) was developed and assessed. PATIENTS AND METHODS: This prospective observational study included 192 term women who underwent induction of labor. First, a wide range of clinical and ultrasound pre-induction parameters were recorded. The induction was initiated by endocervical administration of dinoprostone gel (for Bishop score ≤5) or intravenous oxytocin (for Bishop score ≥6). After evaluating ultrasound parameters, we created an ultrasound scoring system and compared it with the Bishop score and clinical parameters. Finally, a comprehensive model using machine learning algorithms for predicting the success of the induction of labor was developed. RESULTS: In terms of clinical parameters, this study found that IOL correlates with parity, body mass index (BMI) (both at p<0.05), and the Bishop score (p<0.001). All ultrasound parameters were statistically significant (p<0.05) apart from the posterior cervical angle. However, compared to the Bishop score, the new USS showed a slightly lower sensitivity (0.55 compared to 0.64) but much higher specificity (0.75 compared to 0.44) at a cut-off of 1.66. The proposed model, which can predict 83% of the events correctly, encompasses the Bishop score, USS, and clinical parameters. CONCLUSIONS: The findings imply that the model developed in this study, which takes into account clinical parameters (parity, BMI), the ultrasound parameters and the Bishop score and uses machine learning algorithms, yields better results than models using other parameters.

Three-dimensional assessment of interfractional cervical and uterine motions using daily magnetic resonance images to determine margins and timing of replanning.

PURPOSE: This study was conducted to determine the margins and timing of replanning by assessing the daily interfractional cervical and uterine motions using magnetic resonance (MR) images. METHODS: Eleven patients with cervical cancer, who underwent intensity-modulated radiotherapy (IMRT) in 23-25 fractions, were considered in this study. The daily and reference MR images were converted into three-dimensional (3D) shape models. Patient-specific anisotropic margins were calculated from the proximal 95% of vertices located outside the surface of the reference model. Population-based margins were defined as the 90th percentile values of the patient-specific margins. The expanded volume of interest (expVOI) for the cervix and uterus was generated by expanding the reference model based on the population-based margin to calculate the coverage for daily deformable mesh models. For comparison, expVOIconv was generated using conventional margins: right (R), left (L), anterior (A), posterior (P), superior (S), and inferior (I) were (5, 5, 15, 15, 10, 10) and (10, 10, 20, 20, 15, 15) mm for the cervix and uterus, respectively. Subsequently, a replanning scenario was developed based on the cervical volume change. ExpVOIini and expVOIreplan were generated before and after replanning, respectively. RESULTS: Population-based margins were (R, L, A, P, S, I) of (7, 7, 11, 6, 11, 8) and (14, 13, 27, 19, 15, 21) mm for the cervix and uterus, respectively. The timing of replanning was found to be the 16th fraction, and the volume of expVOIreplan decreased by >30% compared to that of expVOIini . However, margins cannot be reduced to ensure equivalent coverage after replanning. CONCLUSION: We determined the margins and timing of replanning through detailed daily analysis. The margins of the cervix were smaller than conventional margins in some directions, while the margins of the uterus were larger in almost all directions. A margin equivalent to that at the initial planning was required for replanning.

Cost-effectiveness of history-indicated cerclage vs cervical length assessment for prevention of preterm birth.

BACKGROUND: Preterm birth is one of the major causes of neonatal morbidity and mortality. Preterm delivery is a large burden to our health care system, and a history of preterm birth is one of the most common risk factors for subsequent preterm birth. OBJECTIVE: We sought to examine the cost-effectiveness of the history-indicated cerclage strategy compared with the transvaginal ultrasound cervical length assessment strategy in individuals with a history of preterm birth. STUDY DESIGN: We developed a decision analysis model to compare history-indicated cerclage and cervical length assessment. The primary outcome was the net monetary benefit from a maternal and neonatal perspective of both strategies, defined as the value of an intervention with a known willingness to pay threshold for a unit of benefit. The time horizon was set to be a lifetime. Costs (in 2022 USD) included those for the cerclage, serial transvaginal ultrasounds, maternal care for admission, neonatal care, and severe disability. Probabilities, utilities, and costs were derived from the literature. A cost-effectiveness threshold was set at $100,000 per QALY (quality-adjusted life year). We first conducted 1-way sensitivity analyses with associated variables as sensitivity analyses. We then performed a probabilistic sensitivity analysis using Monte Carlo simulation with 1000 trials to test the robustness of the results in the setting of simultaneous changes in probabilities, costs, and utilities. RESULTS: In our base-case analysis, the history-indicated cerclage strategy compared to transvaginal ultrasound cervical length assessment was associated with more cost ($85,038 vs $70,155), with slightly less effectiveness from the maternal perspective (26.74 QALY vs 26.78 QALY) and from the neonatal perspective (28.91 QALY vs 29.06 QALY), and with less maternal and neonatal net monetary benefit. Therefore, the history-indicated cerclage strategy was dominated. With the 1000 trials of Monte Carlo simulation, transvaginal ultrasound cervical length assessment was the preferred strategy 84% and 88% of the time from the maternal and neonatal perspectives, respectively. CONCLUSION: The history-indicated cerclage strategy was more expensive and slightly less effective than the transvaginal ultrasound cervical length assessment strategy with a lower net monetary benefit.

Third-trimester cervical length assessment for the prediction of spontaneous late preterm birth.

BACKGROUND: The usefulness of cervical length (CL) measurement in asymptomatic pregnancies in the third trimester of pregnancy is not certain. Therefore, the objective of this study was to assess the performance of CL measurement at 31-34 gestational weeks for the prediction of spontaneous late preterm birth (PTB). MATERIALS AND METHODS: This was a prospective study of women with a singleton pregnancy, who had their routine third-trimester scan at 31-34 weeks. The CL was measured transvaginally and was tested, together with maternal demographic and obstetric parameters, for the prediction of late PTB (34 to 36 weeks), using logistic regression and ROC curve analysis. RESULTS: Overall, from a population of 1003 women that consented to participate in the study, 42 (4.2%) delivered at 34-36 gestational weeks. A significant association was identified between gestational age at birth and CL (rho = 0.182, p < .001), and there were significant differences in the CL between cases of late preterm and term births (p < .001). Cervical length alone could predict 17% of late PTB for a 10% false positive rate, corresponding to 22 mm. A model combining CL with parity and method of conception can identify 35% of pregnancies resulting in late PTB, at a false positive rate of 10% (AUC: 0.750; 95% CI: 0.675-0.824). CONCLUSIONS: CL assessment at 31-34 gestational weeks may contribute to the prediction of late PTB when combined with maternal characteristics.

Transfer learning supported accurate assessment of multiclass cervix type images.

Cervical cancer predominately affects women compared to lung, breast and endometrial cancer. Premature stage identification and proper treatment of this cancer may lead to 100% survival rate. The cervix type is very prominent in the detailed diagnosis of cervical cancer. High expertise and experienced gynecologist are required for an accurate diagnosis of cervical cancer. To reduce their burden, a model is proposed, based on deep learning that automatically classifies the cervix types. This paper presents Modified Deep Convolutional Neural Networks namely Modified VGG16 (MVGG16), Modified VGG19 (MVGG19), Modified ResNet50 (MRN50), Modified InceptionV3 (MIV3), and Modified InceptionResNetV2 (MIRNV2) for the classification of cervix type images. These modified networks are implemented using a Multiclass Support Vector Machine classifier. The performance metrics are tabulated and compared with pre-trained models. The simulation results show that MIRNV2 achieves the best performance compared to other models with an overall Accuracy of 92.91% and a Kappa score of 0.88. MIRNV2 model also gives better classification accuracy of 96.62% for type 1, 93.58% for type 2, and 95.61% for type 3 cervix images. Hence, this facilitates the application of MIRNV2 as a diagnostic tool to assist the gynecologist in the classification of cervix type images.

Preoperative Assessment of Cervical Involvement in Endometrial Cancer by Transvaginal Ultrasound and Magnetic Resonance Imaging: A Systematic Review and Meta-Analysis.

OBJECTIVE: To compare the diagnostic accuracy of transvaginal ultrasound (TVS) and magnetic resonance imaging (MRI) for detecting cervical infiltration by endometrial carcinoma using meta-analysis assessment. METHODS: An extensive search of papers comparing TVS and MRI for assessing cervical infiltration in endometrial cancer in the same set of patients was performed in Medline (Pubmed), Web of Science, and the Cochrane Database. Quality was assessed using QUADAS-2 tool (Quality Assessment of Diagnostic Accuracy Studies-2). Quantitative meta-analysis was performed. RESULTS: Our extended search identified 12 articles that used both techniques in the same set of patients and were included in the meta-analysis. The risk of bias for most studies was high for patient selection and index tests in QUADAS-2. Overall, the pooled estimated sensitivity and specificity for diagnosing cervical infiltration in women with endometrial cancer were identical for both techniques [69 % (95 % CI, 51 %-82 %) and 93 % (95 % CI, 90 %-95 %) for TVS, and 69 % (95 % CI, 57 %-79 %) and 91 % (95 % CI, 90 %-95 %) for MRI, respectively]. No statistical differences were found when comparing both methods. Heterogeneity was high for sensitivity and moderate for specificity when analyzing TVS and moderate for both sensitivity and specificity in the case of MRI. CONCLUSION: TVS and MRI showed very similar diagnostic performance for diagnosing cervical involvement in women with endometrial cancer.

The Overlooked Impact of Lower Uterine Segment Contractions on Second Trimester Cervical Assessment.

INTRODUCTION: Asymptomatic contractions in the lower uterine segment (LUS) may affect uterocervical angle and cervical length (CL); however, this has never been investigated. Therefore, the aim of this study was to evaluate the effect of LUS contractions on uterocervical angle, CL, and LUS thickness. MATERIALS AND METHODS: This was a prospective, observational, single-cohort study conducted on 102 asymptomatic singleton pregnancies between 19.0 and 22.6 weeks of gestation. Uterocervical angle and CL were measured by transvaginal ultrasound at two different time points with an interval of at least 20 min. LUS thickness was also measured as an indirect marker of myometrial contraction. A linear and curvilinear regression were performed to explore a potential association between LUS contractions, measured as increments in LUS thickness, and changes in CL and uterocervical angle. RESULTS: The linear regression between changes in LUS thickness and changes in CL showed that LUS contractions impact CL; for every 1-mm increase in LUS thickness, CL increased by 0.909 mm, when the isthmus was included in the CL measurement (R2 = 0.358; ß = 0.909; p < 0.001). By contrast, when the isthmus was not included in the measurement, a curvilinear relation between changes in LUS thickness and changes in CL was found (R2 = 0.077; ß1 = 0.575, ß2 = 0.038; p = 0.018). The relation between changes in uterocervical angle and changes in LUS thickness was not significant. DISCUSSION/CONCLUSION: LUS contractions can be observed in many asymptomatic women during the second trimester of pregnancy. LUS contractions lead to an increase in CL and LUS thickness, thus impacting ultrasound cervical assessments. These contractions do not affect the uterocervical angle.

Cost-effectiveness of cervical length screening and progesterone treatment to prevent spontaneous preterm delivery in Sweden.

OBJECTIVE: To estimate the cost-effectiveness of strategies to prevent spontaneous preterm delivery (PTD) in asymptomatic singleton pregnancies, using prevalence and healthcare cost data from the Swedish healthcare context. METHODS: We designed a decision analytic model based on the Swedish CERVIX study to estimate the cost-effectiveness of strategies to prevent spontaneous PTD in asymptomatic women with a singleton pregnancy. The model was constructed as a combined decision-tree model and Markov model with a time horizon of 100 years. Four preventive strategies, namely 'Universal screening', 'High-risk-based screening' (i.e. screening of high-risk women only), 'Low-risk-based screening' (i.e. treatment of high-risk population and screening of remaining women) and 'Nullipara screening' (i.e. treatment of high-risk population and screening of nulliparous women only), included second-trimester cervical length (CL) screening by transvaginal ultrasound followed by vaginal progesterone treatment in the case of a short cervix. A fifth preventive strategy involved vaginal progesterone treatment of women with previous spontaneous PTD or late miscarriage but no CL screening ('No screening, treat high-risk group'). For comparison, we used a sixth strategy implying no specific intervention to prevent spontaneous PTD, reflecting the current situation in Sweden ('No screening'). Probabilities for a short cervix (CL ≤ 25 mm; base-case) and for spontaneous PTD at < 33 + 0 weeks and at 33 + 0 to 36 + 6 weeks were derived from the CERVIX study, and probabilities for stillbirth, neonatal mortality and long-term morbidity (cerebral palsy) from Swedish health data registers. Costs were based on Swedish data, except costs for cerebral palsy, which were based on Danish data. We assumed that vaginal progesterone reduces spontaneous PTD before 33 weeks by 30% and spontaneous PTD at 33-36 weeks by 10% (based on the literature). All analyses were from a societal perspective. We expressed the effectiveness of each strategy as gained quality-adjusted life years (QALYs) and presented cost-effectiveness as average (ACER; average cost per gained QALY compared with 'No screening') and incremental (ICER; difference in costs divided by the difference in QALYs for each of two strategies being compared) cost-effectiveness ratios. We performed deterministic and probabilistic sensitivity analysis. The results of the latter are shown as cost-effectiveness acceptability curves. Willingness-to-pay was set at a maximum of 500 000 Swedish krona (56 000 US dollars (USD)), as suggested by the Swedish National Board of Health and Welfare. RESULTS: All interventions had better health outcomes than did 'No screening', with fewer screening-year deaths and more lifetime QALYs. The best strategy in terms of improved health outcomes was 'Low-risk-based screening', irrespective of whether screening was performed at 18 + 0 to 20 + 6 weeks (Cx1) or at 21 + 0 to 23 + 6 weeks (Cx2). 'Low-risk-based screening' at Cx1 was cost-effective, while 'Low-risk-based screening' at Cx2 entailed high costs compared with other alternatives. The ACERs were 2200 USD for 'Low-risk-based screening' at Cx1 and 36 800 USD for 'Low-risk-based screening' at Cx2. Cost-effectiveness was particularly sensitive to progesterone effectiveness and to productivity loss due to sick leave during pregnancy. The probability that 'Low-risk-based screening' at Cx1 is cost-effective compared with 'No screening' was 71%. CONCLUSION: Interventions to prevent spontaneous PTD in asymptomatic women with a singleton pregnancy, including CL screening with progesterone treatment of cases with a short cervix, may be cost-effective in Sweden. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Pre-induction cervical assessment using transvaginal ultrasound versus Bishops cervical scoring as predictors of successful induction of labour in term pregnancies: A hospital-based comparative clinical trial.

OBJECTIVE: To evaluate the association between transvaginal ultrasound scan of cervix and Bishop's score in predicting successful induction of labour, cut-off points and patients' tolerability and acceptance for both procedures. DESIGN: A comparative clinical trial. SETTING: A tertiary hospital in Selangor, Malaysia. PARTICIPANTS: 294 women planned for elective induction of labour for various indications were included. All women had transvaginal ultrasound to assess the cervical length and digital vaginal examination to assess the Bishop cervical scoring by separate investigators before induction of labour. PRIMARY OUTCOME MEASURE: To evaluate the association of the cervical length by transvaginal ultrasound scan and Bishop score in predicting successful induction of labour. SECONDARY OUTCOME MEASURE: Variables associated with successful induction of labour and patients' tolerability and acceptance for transvaginal ultrasound scan of cervix. RESULTS: There was no statistically significant difference among the vaginal and Caesarean delivery groups in terms of mean maternal age, height, weight, body mass index, ethnicity and gestational age at induction. Vaginal delivery occurred in 207 women (70.4%) and 87 women (29.6%) delivered via Caesarean section. There was a high degree of correlation between the cervical length and Bishop score (r-value 0.745; p <0.001). Sonographic assessment of cervical length demonstrated a comparable accuracy in comparison to Bishop score. Analysis using ROC curves noted an optimal cut-off value of ≤27mm for cervical length and Bishop score of ≥ 4, with a sensitivity of 69.1% vs 67%, specificity 60.9% vs 55%, and area under the curves (AUCs) of 0.672 and 0.643 respectively (p <0.001). Multivariate logistic regression analysis demonstrated that parity (OR 2.70), cervical length (OR 0.925), Bishop score (OR 1.272) and presence of funnelling (OR 3.292) were highly significant as independent predictors of success labour induction. Women also expressed significantly less discomfort with transvaginal ultrasound compared with digital vaginal examination. CONCLUSION: Sonographic assessment of cervical measurement predicts the success of induction of labour with similar diagnostic accuracy with conventional Bishop score.

A force-measuring device combined with ultrasound-based elastography for assessment of the uterine cervix.

INTRODUCTION: In this feasibility study, we hypothesize that the evaluation of cervical biomechanical strength can be improved if cervical length measurement is supplemented with quantitative elastography, which is a technique based on conventional ultrasound elastography combined with a force-measuring device. Our aims were to: (a) develop a force-measuring device; (b) introduce a cervical elastography index (CEI) and a cervical strength index (CSI; defined as cervical length × CEI); (c) evaluate how these indexes assess the cervical softening that takes place during normal pregnancy; and (d) how these indexes predict the cervical dilatation time from 4 to 10 cm. MATERIAL AND METHODS: An electronic force-measuring device was mounted on the handle of the transvaginal probe, allowing for force measurement when conducting elastography. The study group concerned with normal cervical softening included 44 unselected pregnant women. Outcomes were CEI and CSI at different gestational ages. The study group for labor induction included 26 singleton term pregnant women admitted for labor induction. Outcome was defined as cervical dilatation time from 4 to 10 cm. Elastography measured the changes in mean gray value (intensity) during manual compressions. Region of interest was set within the anterior cervical lip. RESULTS: We found that the mean of all variables regarding cervical softening decreased from early to late pregnancy: ie cervical length from 34 to 29 mm, CEI from 0.17 to 0.11 N, and CSI from 5.9 to 3.1 N mm. Moreover, the cervical dilatation time during labor induction was associated with CEI, although not statistically significantly (area under the ROC curve of 0.67), but not with the Bishop score, the cervical length, or the CSI. CONCLUSIONS: We propose that quantitative elastography based on changes in the intensity of the B-mode ultrasound recording, in combination with a force-measuring device on the handle of the vaginal probe, deserves further investigation as an approach for evaluation of cervical biomechanical strength.

Sonoelastography for the comparative assessment of cervical maturation after different approaches to cervical preparation ahead of labor induction.

AIM: To compare the efficacy of different approaches to cervical preparation to labor induction using the ultrasound cervical elastography. MATERIALS AND METHODS: This prospective open-label study included 200 pregnant women aged between 23 and 38 years eligible for labor pre-induction. Patients were divided into four groups (n = 50 per group). In Group I, four osmotic Dilapan-S cervical dilators combined with two doses of oral mifepristone (200 mg each) 24 h apart were used. The dilators were inserted for up to 12 h. In Group II, only the Dipalan-S dilators were used. In Group III, a Foley catheter was positioned intracervically for 12 h. In Group IV, we used two doses of intracervical prostaglandin E2 gel (0.5 mg each) 6 h apart. Cervical maturation was assessed using the Bishop scoring system and the ultrasound cervicometry with the color mapping and calculation of SR ratio. At baseline, all participants were also divided into three subgroups depending on the Bishop score before the pre-induction. Subgroup А (n = 66) included patients with the Bishop score between 0‒2 points, subgroup B (n = 69) between 3-4 points, and subgroup С (n = 65) between 4-6 points. RESULTS: Our study showed that the efficacy of Dilapan-S combined with mifepristone for cervical preparation to labor induction was higher than Dilapan-S, Foley catheter and intracervical prostaglandin E2 gel. In this group, the Bishop score after the pre-induction was the highest (11.4 (0.21) points versus 10.2 (0.2), 9.4 (0.3) и 9.67 (0.25) in Groups II, III and IV respectively (p < .05 for all). The lowest SR values were also observed among the patients receiving the combination of Dilapan-S and mifepristone: 1.23 (0.04) versus 1.63 (0.07), 1.7 (0.08) and 1.83 (0.1) in Groups II, III and IV respectively (p < .05 for all). The sonoelastographic SR values in subgroups B and C were statistically lower compared with subgroup A across all groups studied. Ultrasound elastography of the cervix allowed to perform a more objective assessment of cervical maturation compared with the Bishop scoring. CONCLUSION: Dilapan-S combined with mifepristone had higher efficacy for cervical preparation to labor induction compared with other approaches investigated.

Intrapartum ultrasound for assessment of cervical dilatation.

Assessment of cervical dilatation by digital vaginal examination is commonly used during labor as one of the main indicators of labor progress. Despite consistent inaccuracies, this practice remains widely chosen among midwives and obstetricians. Several methods, including electromechanical and electromagnetic devices, have been trialed throughout the decades without being able to provide objective means of obtaining accurate measurements of cervical dilatation during labor. Intrapartum ultrasound in the form of transperineal or translabial applications has shown promising results in the assessment and monitoring of labor progress. Here, we described the validity of intrapartum ultrasound and its usefulness in the assessment of cervical dilatation during labor. Moreover, we highlighted the feasibility of ultrasound in obtaining these assessments.