Cervical Length Assessment Research Articles

A comparative study between modified Bishop score and transvaginal sonography to predict successful induction of labor

ABSTRACT Background: Modified Bishop score (MBS) and cervical length determination by transvaginal sonography (TVS) are the two methods for predicting successful vaginal delivery based on pre-induction favourability of the cervix. Aims and Objectives: This study compared both methods for predicting successful vaginal delivery. The primary objective was to compare the predictive value of MBS and TVS in predicting successful induction of labor. The secondary objective was to obtain the cut-off score of MBS and TVS for successful induction of labor. Methods: A prospective study was done involving 100 pregnant women admitted for induction of labor. TVS was done to measure the cervical length before induction of labor. MBS was also calculated for all the patients. Labor was induced with prostaglandins. Labor induction was considered successful if there was an onset of uterine contractions and cervical dilatation within 24 h of induction. Results: For successful induction of labor, the cutoff of cervical length by TVS and MBS was 2.5 cm and 6, respectively. Cervical length assessment by TVS performed better than the MBS (sensitivity 61.8% vs. 28.9%, Specificity 95.8% vs. 100%). Conclusion: MBS and cervical length measurement by sonography both are good predictors of successful induction of labor. Cervical length measurement by TVS provides a better prediction of the likelihood of vaginal delivery.

Evaluation of antenatal care quality for preterm birth prevention using an auditable scoring system: A retrospective, descriptive, longitudinal study in Sydney, Australia.

Preterm birth continues to be one of the most significant contributors to perinatal death. This study aims to evaluate the quality of antenatal care provided to women delivering preterm. This was a retrospective, descriptive, longitudinal review of all women who had antenatal care within a single Australian tertiary hospital and delivered spontaneously between 24 and 37 weeks of gestation, using an auditable scoring system assessing potential interventions for prevention of preterm birth. The review was limited to singleton pregnancies without fetal abnormalities delivering between January 2013 and April 2015. The audit tool was developed by reference to established 'best practice' guidance for prediction and prevention of preterm birth based on Royal Australian and New Zealand College of Obstetricians and Gynaecologists guidelines and published literature. Different pathways were assessed for women deemed either low- or high-risk at the outset of antenatal care. A series of 161 pregnancies that delivered preterm (between 24 and 37 weeks' gestation) were reviewed. The quality of antenatal care was scored 'good' in 42.9% and 50% of high-risk and low-risk women, respectively. Care was scored 'adequate', with room for improvement in 51.4% and 45.2% of the two corresponding groups. The main deficiencies in care were recorded evidence of assessment of cervical length (absent in 35% of cases) and failure to screen for bacterial vaginosis in high-risk women. Auditing antenatal care for prevention of preterm birth allows identification of suboptimal practice allowing service improvement and potential intervention for preterm birth prevention.

Assessment of obstetric history and cervical length as risk factors for preterm birth

Assessment of obstetric history and cervical length as risk factors for preterm birth

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.

SMFM Consult Series #70: Management of short cervix in individuals without a history of spontaneous preterm birth

The majority of deliveries before 34 weeks of gestation occur in individuals with no prior history of preterm birth. Mid-trimester cervical length assessment by transvaginal ultrasound is one of the best clinical predictors of spontaneous preterm birth. This Consult provides guidance for the diagnosis and management of short cervix in an individual without a history of preterm birth. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend that all cervical length measurements used to guide therapeutic recommendations be performed using a transvaginal approach and in accordance with standardized procedures as described by organizations such as the Perinatal Quality Foundation or the Fetal Medicine Foundation (GRADE 1C); (2) we recommend using a midtrimester cervical length of ≤ 25 mm to diagnose short cervix in individuals with a singleton gestation and no prior history of spontaneous preterm birth (GRADE 1C); (3) we recommend that asymptomatic individuals with a singleton gestation and a transvaginal cervical length of ≤ 20 mm diagnosed prior to 24 weeks of gestation be prescribed vaginal progesterone to reduce the risk of preterm birth (GRADE 1A); (4) we recommend that treatment with vaginal progesterone be considered at a cervical length of 21 to 25 mm based on shared decision-making (GRADE 1B); (5) we recommend that 17-OHPC, including compounded formulations, not be prescribed for the treatment of a short cervix (GRADE 1B); (6) in individuals without a history of preterm birth who have a sonographic short cervix (10-25 mm), we recommend against cerclage placement in the absence of cervical dilation (GRADE 1B); (7) we recommend that cervical pessary not be placed for the prevention of preterm birth in individuals with a singleton gestation and a short cervix (GRADE 1B); (8) we recommend against routine use of progesterone, pessary, or cerclage for treatment of cervical shortening in twin gestations outside the context of a clinical trial (GRADE 1B).

The Assessment of Cervical Length and Thickness of Cesarean Section Scar as Predictors for Preterm Labor in Patients with Previous Cesarean Section: A Prospective Cohort Study

The Assessment of Cervical Length and Thickness of Cesarean Section Scar as Predictors for Preterm Labor in Patients with Previous Cesarean Section: A Prospective Cohort Study

Ultrasound assessment of fetal head-perineum distance and cervical length to predict the success of labour induction

Ultrasound assessment of fetal head-perineum distance and cervical length to predict the success of labour induction

EVALUATING THE ROLE OF CERVICAL LENGTH MEASUREMENT IN PREDICTING PRETERM BIRTH: A SYSTEMATIC ANALYSIS

Evaluating cervical length measurement as a predictive tool for preterm birth is a critical focus in obstetrics and maternal-fetal medicine. The primary aim of this study is to find the role of cervical length measurement in predicting preterm birth. This prospective study was conducted in Lady Reading Hospital Peshawar from 2022 to 2023. Two hundred twenty pregnant females in their second trimester were recruited from the hospital's OPD. Baseline information is collected, including socio-demographic factors, clinical and medical history, and obstetric records. A transvaginal ultrasound assesses cervical length using standardised techniques. Baseline measurements serve as the initial data point for subsequent evaluations. Data were collected from 220 pregnant females. The mean age was 28.5 years (±4.2), and the gestational age was 22 weeks (18-24). The average BMI stood at 25.1 kg/m² (±3.5). Non-smokers constituted the majority, accounting for 81.8%, while smokers comprised 18.2% of the cohort. The mean cervical length at 22 weeks was 35.4 mm (±4.6), ranging from 25 mm to 45 mm. The incidence of preterm birth stood at 14% (n=31), with 27% (n=17) of individuals having a cervical length ≤25 mm experiencing preterm birth, whereas 8% (n=14) with a cervical length >25 mm faced the same. Progesterone was administered to 27.3% (n=60) of participants, while 72.7% (n=160) did not receive it. It is concluded that cervical length assessment at 22 weeks gestation presents a valuable predictor for preterm birth incidence within this cohort. The study highlighted a significant correlation between a cervical length of 25 mm or less and an increased risk of preterm delivery.

TVS-guided cervical strain elastography is more effective than measuring cervical length as an independent predictor of spontaneous preterm delivery in asymptomatic, high-risk women during the mid-trimester

Introduction 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. Aim 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. Method 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. Results 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. Conclusions 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.

Comparison between trans-vaginal and trans-abdominal ultrasound examination of the cervix in the second trimester of pregnancy: a prospective study.

To compare transvaginal (TV) and trans-abdominal (TA) ultrasound assessment of cervical length (CL) at the time of the second-trimester scan for fetal anomalies. This was a prospective study including consecutive pregnant women attending the low-risk ultrasound clinic of two fetal medicine centres in Italy. The inclusion criteria were women between 19+0 and 22+0weeks of gestation, attending the prenatal ultrasound clinic for the routine second trimester screening for fetal anomalies. The primary outcome was to compare the CL measurement obtained at TV compared to TA ultrasound; the secondary outcome was to report the inter and intra-observer variability of CL measured with the two different approaches. All women underwent TV and TA assessment of the cervix performed by two experienced certified operators, blinded to each other. Intra-class correlation coefficients (ICC) and Bland-Altman analyses were used to analyse the data. Two hundred and fifty women were included in the analysis. All women had anteverted uterus. The mean gestational age at ultrasound was 20.7±0.7weeks; 1.2 % (3/250) scans were performed at 19weeks, 49.2 % (123/250) at 20weeks, 44.8 % (112/250) at 21weeks and 4.8 % (12/250) at 22weeks of gestations. Identification of the major landmarks of CL at TA ultrasound was achieved in all the included cases. There was good reliability between CL measured at TA (ICC 0.95, 95 % CI 0.93-0.97 for observer 1 and 0.92 %, 95 % CI0.89-0.94 for observer 2) and TV ultrasound 0.97, 95 % CI0.96-0.98 for observer 1 and 0.96, 95 % CI 0.95-0.97 for observer 2). There was also good reliability between the two observers for both the TA and TV assessment of the CL. Mean TA CL was 41.4±5.5 for observer 1 and 40.5±4.8 for observer 2 with no significant differences between the two measurements (mean difference 0.92 mm, 95 % CI-9.7 to 11.2). Likewise, there was no difference between the CL measured at TV ultrasound between the two observers (mean difference-0.83 mm, 95 % CI-5.97 to 4.30). Finally, there was no difference in the mean CL measured at TA compared to TV, either considering the overall population of women (mean difference:-0.43, 955 CI-8.65 to 7.79), or when stratifying the analysis according to the parity status and the operator. Among experienced operators, there was no difference between TV and TA ultrasound assessment of the CL at the time of the routine anomaly scan for fetal anomaly.

Real-time ultrasound demonstration of uterine isthmus contractions during pregnancy

Asymptomatic isthmic contractions are a frequent physiological phenomenon in pregnancy, sometimes triggered by bladder voiding. They can interfere with proper cervical length assessment and may lead to false images of placenta previa. However, there is limited research on the prevalence and characteristics of these contractions. This study aimed to determine the prevalence and characteristics of isthmic contractions after bladder voiding in the second trimester of pregnancy, to evaluate their effect on cervical length assessment, and to propose a new method for the objective assessment of the presence and intensity of isthmic contractions. In this prospective observational study, long videos of the uterine cervix were recorded in 30 singleton pregnancies during the second trimester of pregnancy after bladder voiding. Isthmic length and cervicoisthmic length changes were assessed over time. The isthmic length was measured using a new approach, which involved calculating the distance from the base of the cervix to the internal os, including the isthmus. Isthmic contractions were observed in 43% of pregnant women (95% confidence interval, 26%-62%) after bladder voiding. The median time for complete isthmus relaxation was 19.7 minutes (95% confidence interval, 15.0 to not available). No substantial differences in maternal characteristics were found between individuals with and without contractions. The proposed method for measuring isthmic length provided an objective assessment of the presence and intensity of isthmic contractions. A cutoff of 18 mm in isthmic length allowed for the distinction of pregnant women presenting a contraction. In addition, the study identified a characteristic undulatory pattern in the relaxation of the isthmus in half of the cases with contractions. Isthmic contractions are a common occurrence after bladder voiding in the second trimester of pregnancy and may interfere with proper cervical length assessment. We recommend performing cervical assessment at least 20 minutes after bladder voiding to reduce the risk of bias in cervical length measurement and to avoid false images of placenta previa. The new method for measuring isthmic length provides an objective way to assess the presence and intensity of isthmic contractions. Further research is needed to understand the role of isthmic contractions in the physiology of pregnancy and birth.

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

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. 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. 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. 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. 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.

Longitudinal change in cervical length following vaginal or abdominal cervical cerclage: a randomized comparison

Cervical cerclage has been shown to reduce the risk of recurrent spontaneous preterm birth in a high-risk patient population; however, the mechanism is not well understood. Transabdominal cerclage is superior to low and high vaginal cerclage in reducing early spontaneous preterm birth and fetal loss in women with previous failed vaginal cerclage. Cervical length measurements are commonly used to monitor high-risk women and may explain the mechanism of success. This study aimed to evaluate the rate of change in longitudinal cervical length after randomized placement of low transvaginal, high transvaginal, or transabdominal cerclage in women with a previous failed vaginal cerclage. This was a planned analysis of longitudinal transvaginal ultrasound cervical length measurements from patients enrolled in the Vaginal Randomised Intervention of Cerclage trial, a randomized controlled trial comparing transabdominal cerclage or high transvaginal cerclage with low transvaginal cerclage. Cervical length measurements at specific gestational ages were compared over time and between groups, using generalized estimating equations fitted using the maximum-likelihood random-effects estimator. In addition, cervical length measurements were compared in women with transabdominal cerclage placed before and during pregnancy. The diagnostic accuracy of cervical length as a predictor of spontaneous preterm birth at <32 weeks of gestation was explored. This study included 78 women who underwent longitudinal cervical length assessment (70% of the analyzed cohort) with a history of failed cerclage, of whom 25 (32%) were randomized to low transvaginal cerclage, 26 (33%) to high transvaginal cerclage, and 27 (35%) to transabdominal cerclage. Abdominal cerclage was superior to low (P=.008) and high (P=.001) vaginal cerclage at maintaining cervical length over the surveillance period (14 to 26 weeks of gestation) (+0.08 mm/week, 95% confidence interval, -0.40 to 0.22; P=.580). On average, the cervical length was 1.8 mm longer by the end of the 12-week surveillance period in women with transabdominal cerclage (+1.8 mm; 95% confidence interval, -7.89 to 4.30; P=.564). High vaginal cerclage was no better than low cervical cerclage in the prevention of cervical shortening; the cervix shortened by 13.2 mm over 12 weeks in those with low vaginal cerclage (95% confidence interval, -21.7 to -4.7; P=.002) and by 20 mm over 12 weeks in those with high vaginal cerclage (95% confidence interval, -33.1 to -7.4; P=.002). Preconception transabdominal cerclage resulted in a longer cervix than those performed during pregnancy; this difference was significant after 22 weeks of gestation (48.5 mm vs 39.6 mm; P=.039). Overall, cervical length was an excellent predictor of spontaneous preterm birth at <32 weeks of gestation (receiver operating characteristic curve, 0.92; 95% confidence interval, 0.82-1.00). In women with a previous failed cervical cerclage, in the next pregnancy, the cervical length in women treated with vaginal cerclage funneled and shortened over time, whereas there was preservation of cervical length in women who receive transabdominal cerclage. Cervical length remained longer in transabdominal procedures performed before pregnancy than in transabdominal procedures performed during pregnancy. Overall, cervical length was an excellent predictor of spontaneous preterm birth in our cohort. Our findings may explain the mechanism of benefit for transabdominal cerclage, with its high placement better maintaining the structural integrity of the cervix at the level of the internal os.

Predicting Spontaneous Pre-term Birth Risk Is Improved When Quantitative Ultrasound Data Are Included With Historical Clinical Data.

Predicting women at risk for spontaneous pre-term birth (sPTB) has been medically challenging because of the lack of signs and symptoms of pre-term birth until interventions are too late. We hypothesized that prediction of the sPTB risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared with using only HC data. HC data defined herein included birth history prior to that of the current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment and physical examination data. The study population included 248 full-term births (FTBs) and 26 sPTBs. QUS scans (Siemens S2000 and MC9-4) were performed by registered diagnostic medical sonographers using a standard cervical length approach. Two cervical QUS scans were conducted at 20 ± 2 and 24 ± 2 wk of gestation. Multiple QUS features were evaluated from calibrated raw radiofrequency backscattered ultrasonic signals. Two statistical models designed to determine sPTB risk were compared: (i) HC data alone and (ii) combined HC and QUS data. Model comparisons included a likelihood ratio test, cross-validated receiver operating characteristic area under the curve, sensitivity and specificity. The study's birth outcomes were only FTBs and sPTBs; medically induced pre-term births were not included. Combined HC and QUS data identified women at risk of sPTB with better AUC (0.68, 95% confidence interval [CI]: 0.57-0.78) compared with HC data alone (0.53, 95% CI: 0.40-0.66) and HC data+cervical length at 18-20 wk of gestation (average AUC=0.51, 95% CI: 0.38-0.64). A likelihood ratio test for significance of QUS features in the classification model was highly statistically significant (p < 0.01). Even with only 26 sPTBs among 274 births, value was added in predicting sPTB when QUS data were included with HC data.

Predicting spontaneous preterm birth in asymptomatic high-risk women with cervical cerclage.

To determine the performance of the predictive markers of spontaneous preterm birth, cervicovaginal quantitative fetal fibronectin (fFN) and cervical length, in asymptomatic high-risk women with transabdominal, history-indicated or ultrasound-indicated cervical cerclage. This was a secondary analysis of a prospective cohort of asymptomatic high-risk women with cervical cerclage and no other prophylactic intervention (including progesterone), who attended the preterm birth clinic at a central London teaching hospital between October 2010 and September 2016. Women had either transabdominal cerclage, placed prior to conception, history-indicated cerclage, placed before 14 weeks' gestation, or ultrasound-indicated cerclage for a short cervix (< 25 mm), placed before 24 weeks. All women underwent serial cervical length assessment on transvaginal ultrasound in the second trimester (16-28 weeks), and quantitative fFN testing from 18 weeks onward. Test performance was analyzed for the prediction of spontaneous preterm birth before 30 weeks (cerclage failure), 34 weeks and 37 weeks, using receiver-operating-characteristics (ROC)-curve analysis. Overall, 181 women were included in the analysis. Cervical length and fFN were strong predictors of spontaneous preterm birth before 30 weeks in women with cerclage, with areas under the ROC curve (AUC) of 0.86 (95% CI, 0.79-0.94) and 0.84 (95% CI, 0.75-0.92), respectively. Cervical length was a better predictor of preterm birth before 30 weeks in women with history-indicated compared to those with ultrasound-indicated cerclage, although both showed clinical utility (AUC, 0.96 (95% CI, 0.91-1.00) vs 0.79 (95% CI, 0.66-0.91); P = 0.01). Quantitative fFN was a strong predictor of spontaneous preterm birth before 30 weeks in women with history-indicated cerclage (AUC, 0.91 (95% CI, 0.75-1.00)) and retained clinical utility in those with ultrasound-indicated cerclage (AUC, 0.76 (95% CI, 0.64-0.89)). There were no spontaneous deliveries before 34 weeks in women with a transabdominal cerclage, so AUC was not calculated. Delivery was delayed significantly in this group (P < 0.01). Cervical length and quantitative fFN retain clinical utility for the prediction of spontaneous preterm birth in women with cervical cerclage, and prediction is best in women with a history-indicated stitch. These tests can be relied upon to discriminate risk and have utility when planning clinical management with regard to treatment failure. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

Transabdominal and transvaginal ultrasound assessment of cervical length - can transvaginal approach be avoided?

This study aimed to compare transabdominal (TA) and transvaginal (TV) ultrasound assessment of cervical length during pregnancy and to establish cervical length above which transvaginal measurement is not necessary. Cervical length was measured using TA and TV method in the first (11 + 0-13 + 6 weeks), the second (20 + 0-21 + 6 weeks) and the third trimester (28 + 0-31 + 6 weeks) in 250 women with singleton pregnancy and low risk for preterm birth. If the cervical length measured in the second trimester of pregnancy with transabdominal approach is ≥ 28.5 mm and ≥ 30.5 mm in the third trimester, it can be assumed with 100% sensitivity the cervical length measured with transvaginal method will be > 25 mm. Transabdominal cervical length measurement in the second and third trimester allows 89% and 65% of patients, respectively, to avoid transvaginal scan. Second and third trimester screening by transabdominal cervical length measurements in a group of pregnant women with low risk for preterm birth is useful to determine which patients require transvaginal measurement.

Undiagnosed Supra-vaginal Cervical Elongation in a Case of Recurrent Pelvic Organ Prolapse After Sacrospinous Hysteropexy: A Case Report

: Cervical elongation (CE) can occur in company with pelvic organ prolapse (POP). Preoperative cervical length assessment is imperative before decision-making for pelvic organ prolapse surgical repair. POP-Q is not effective at recognizing supra-vaginal elongation. In this case study, we are reporting a 70-year-old woman, a case of recurrent POP after sacrospinous hysteropexy, that POP-Q failed in diagnosing supra-vaginal elongation preoperatively. POP-Q is not effective at recognizing supra-vaginal elongation.

Quantitative ultrasound for preterm birth risk prediction—Part 1: Statistical evaluation

Hypothesis: Predicting the spontaneous preterm birth (sPTB) risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared to using only HC data. HC data defined herein includebirth history prior to that of the current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment, and physical examination data. Study population included 248 full-term births (FTBs) and 26 sPTBs. Advanced statistical analyses were performed for supervised classification containing 53 scaled candidate features (48 QUS, 5 HC) using nested fivefold cross-validation of L1-penalized linear logistic regression with 1000 repetitions to identify potential predictors. Statistical models for HC data alone and HC + QUS data were compared with likelihood-ratio test, cross-validated receiver operating characteristic (ROC) area under the curve (AUC), sensitivity, and specificity. To assess performance, the ROC-AUC was estimated with 10-fold cross-validation logistic regression and 1000 repetitions. Averaged ROC curves plus AUCs were computed using threshold averaging. AUC confidence intervals and test statistics to test the two ROC curves’ differences were constructed via DeLong method. Combined HC and QUS data identified women at sPTB risk with better AUC (0.68; 95% CI, 0.57–0.78) than those of HC data alone (0.53; 95% CI, 0.40–0.66). [Work supported by NIHR01HD089935.]

Predicting spontaneous PTB risk is improved when quantitative ultrasound data are included with clinical data

Predicting women at risk for spontaneous preterm birth (sPTB) has been medically challenging due to the lack of signs and symptoms of preterm labor until intervention is too late. Hypothesis: Predicting the sPTB risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared to using only HC data, with HC data being defined as birth history prior current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment, and data from a physical exam. Study population included 250 full-term births (FTBs) and 25 sPTBs. QUS scans (Siemens S2000 & MC9-4) were performed using a standard cervical length approach by RDMS sonographers. QUS is a measure of cervical remodeling at the microstructure level. Two cervical QUS scans were conducted at 20±2 and 24±2 weeks’ gestation. Multiple QUS features were evaluated from calibrated raw radiofrequency backscattered ultrasonic signals. Two statistical models designed to determine sPTB risk were compared: 1) HC data alone and 2) combined HC and QUS data. Test ROC AUC compared both models. The study’s birth outcomes were only FTBs or sPTBs; medically induced preterm births were not included. Combined HC and QUS data identified women at sPTB risk with better AUC (0.68; 95% CI, 0.58-0.78) than that of HC data alone (0.52; 95% CI, 0.38-0.65). A likelihood ratio test for significance of QUS features in the classification model was highly statistically significant (p < 0.01). Traditional risk factors for sPTB (age, parity, previous history of PTB, cervical length < 25 mm, smoking, BMI and alcohol use) were not predictive of sPTB in our sample of participants. Cervical length measurements and HC have been the mainstay of risk assessment for sPTB for years because no other credible biomarkers were available. Even with only 25 sPTBs, there was value-added for predicting sPTB when QUS data were included with HC data.