Ultrasound Assessment Of Cervical Length Research Articles

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.

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.

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.

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.

Reproducibility of assessment of full-dilatation Cesarean section scar in women undergoing second-trimester screening for preterm birth.

ABSTRACTObjectiveTo assess the reproducibility of a standardized method of measuring the Cesarean section (CS) scar, CS scar niche and their position relative to the internal os of the uterine cervix by transvaginal ultrasound in pregnant women with a previous full‐dilatation CS.MethodsThis was a prospective, single‐center reproducibility study on women with a singleton pregnancy and a previous full‐dilatation CS who underwent transvaginal ultrasound assessment of cervical length and CS scar characteristics at 14–24 weeks' gestation. The CS scar was identified as a hypoechogenic linear discontinuity of the myometrium at the anterior wall of the lower uterine segment or cervix. The CS scar niche was identified as an indentation at the site of the scar with a depth of at least 2 mm. The CS scar position was evaluated by measuring the distance to the internal cervical os. CS scar niche parameters, including its length, depth, width, and residual and adjacent myometrial thickness, were assessed in the sagittal and transverse planes. Qualitative reproducibility was assessed by agreement regarding visibility of the CS scar and niche. Quantitative reproducibility of CS scar measurements was assessed using three sets of images: (1) real‐time two‐dimensional (2D) images (real‐time acquisition and caliper placement on 2D images by two operators), (2) offline 2D still images (offline caliper placement by two operators on stored 2D images acquired by one operator) and (3) three‐dimensional (3D) volume images (volume manipulation and caliper placement on 2D images extracted by two operators). Agreement on CS scar visibility and the presence of a niche was analyzed using kappa coefficients. Intraobserver and interobserver reproducibility of quantitative measurements was assessed using Bland–Altman plots.ResultsTo achieve the desired statistical power, 72 women were recruited. The CS scar was visualized in > 80% of images. Interobserver agreement for scar visualization and presence of a niche in real‐time 2D images was excellent (kappa coefficients of 0.84 and 0.85, respectively). Overall, reproducibility was higher for real‐time 2D and offline 2D still images than for 3D volume images. The 95% limits of agreement (LOA) for intraobserver reproducibility were between ± 1.1 and ± 3.6 mm for all sets of images; the 95% LOA for interobserver reproducibility were between ± 2.0 and ± 6.3 mm. Measurement of the distance from the CS scar to the internal cervical os was the most reproducible 2D measurement (intraobserver and interobserver 95% LOA within ± 1.6 and ± 2.7 mm, respectively). Overall, niche measurements were the least reproducible measurements (intraobserver 95% LOA between ± 1.6 and ± 3.6 mm; interobserver 95% LOA between ± 3.1 and ± 6.3 mm). There was no consistent difference between measurements obtained by reacquisition of 2D images (planes obtained twice and caliper placed), caliper placement on 2D stored images or volume manipulation (planes obtained twice and caliper placed).ConclusionsThe CS scar position and scar niche in pregnant women with a previous full‐dilatation CS can be assessed in the second trimester of a subsequent pregnancy using either 2D or 3D volume ultrasound imaging with a high level of reproducibility. Overall, the most reproducible CS scar parameter is the distance from the CS scar to the internal cervical os. The method proposed in this study should enable clinicians to assess the CS scar reliably and may help predict pregnancy outcome. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Transvaginal Ultrasound Assessment of Cervical Length in Threatened Preterm Labor

Objectives: To determine the cut off point of cervical length usingtransvaginal ultrasonography to predict the actual occurrence ofpreterm labor in women with threatened preterm labor.
 Methods: A cross sectional study with consecutive random samplingmethod. We examined 80 women with singleton pregnancycomplaining of regular, painful uterine contraction and rupturedmembrane at 24-36 weeks of gestation. Women in active labor, definedby the presence of cervical dilatation less than or equal 3 cm, and having complicationwere excluded. When the patient was admitted, a transvaginalscan was performed to measure the cervical length. Parenteralmagnesium sulfate was given as the subsequent management.The primary outcome was delivery within 24 hours of presentation.Results: We found that the optimal cut off values for cervical lengthwas 2.65 cm with sensitivity 94.4 Percent, specificity 65.4Percent, positive predictivevalue 75.4 Percent and negative predictive value 81.8 Percent. In 69cases, the cervical length was more than or 2.65 cm, with 52 patients successfullycontinued their pregnancy until more than 24 hours. In the 11cases with cervical length less than or equal 2.65 cm, delivery within 24 hours occurredin 9 cases (81,8 Percent).
 Conclusion: The findings of this study suggest that in women withthreatened preterm labor, cervical length more than or equal 2.65 cm may help predictthe actual occurrence of preterm labor.
 Keywords: cervical length, threatened preterm labor, transvaginalultrasonography

Development and validation of predictive models for QUiPP App v.2: tool for predicting preterm birth in women with symptoms of threatened preterm labor

To develop enhanced prediction models to update the QUiPP App prototype, a tool providing individualized risk of spontaneous preterm birth (sPTB), for use in women with symptoms of threatened preterm labor (TPTL), incorporating risk factors, transvaginal ultrasound assessment of cervical length (CL) and cervicovaginal fluid quantitative fetal fibronectin (qfFN) test results. Participants were pregnant women between 23 + 0 and 34 + 6 weeks' gestation with symptoms of TPTL, recruited as part of four prospective cohort studies carried out at 16 UK hospitals between October 2010 and October 2017. The training set comprised all women whose outcomes were known in May 2017 (n = 1032). The validation set comprised women whose outcomes were gathered between June 2017 and March 2018 (n = 506). Parametric survival models were developed for three combinations of predictors: risk factors plus qfFN test results alone, risk factors plus CL alone, and risk factors plus both qfFN and CL. The best models were selected using the Akaike and Bayesian information criteria. The estimated probability of sPTB < 30, < 34 or < 37 weeks' gestation and within 1 or 2 weeks of testing was calculated and receiver-operating-characteristics (ROC) curves were created to demonstrate the diagnostic ability of the prediction models. Predictive statistics were similar between the training and the validation sets at most outcome time points and for each combination of predictors. Areas under the ROC curves (AUC) demonstrated that all three algorithms had good accuracy for the prediction of sPTB at < 30, < 34 and < 37 weeks' gestation and within 1 and 2 weeks' post-testing in the validation set, particularly the model combining risk factors plus qfFN alone (AUC: 0.96 at < 30 weeks; 0.85 at < 34 weeks; 0.77 at < 37 weeks; 0.91 at < 1 week from testing; and 0.92 at < 2 weeks from testing). Validation of the new prediction models suggests that the QUiPP App v.2 can reliably calculate risk of sPTB in women with TPTL. Use of the QUiPP App in practice could lead to better targeting of intervention, while providing reassurance and avoiding unnecessary intervention in women at low risk. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Comparison of transabdominal and transvaginal ultrasonography for the assessment of cervical length in the third trimester of pregnancy

ObjectiveThis study aimed to compare TA and transvaginal (TV) ultrasound assessment of cervical length (CL), as well as to assess the feasibility of the TA approach in the third trimester of pregnancy. Materials and methodsThis was prospective study of low-risk women at 31–34 gestational weeks who underwent TA and TV CL measurements during a routine 3rd trimester scan. All examinations were performed by one operator who was blind to the measurements. Differences between the two methods were evaluated. Results240 women were initially enrolled in the study. Paired TA and TV measurements were obtained in 123 (51.3%) women. The mean TV CL was 35.2 ± 6.8 mm and the mean TA CL was 34.7 ± 6.5 mm. There was a significant correlation between the CL measured by the two different methods (r = 0.816). No significant differences were identified between the mean CL measurements of the two techniques (t = −1.360; p = 0.176). Moreover, regarding the feasibility of TA technique, it was less likely to obtain TA CL images in cases with a cephalic fetal presentation (p = 0.028). ConclusionAt 31–34 gestational weeks, with an empty bladder, the cervix can be visualized by the TA approach in only about half of the cases (51.3%). The TA CL measurements show a significant correlation with the TV ones. More research is needed to determine the potential predictive value of the TA ultrasound for preterm labor.

Cervical length and quantitative fetal fibronectin in the prediction of spontaneous preterm birth in asymptomatic women with congenital uterine anomaly

Congenital uterine anomalies are associated with late miscarriage and spontaneous preterm birth. Our aim was 1) to determine the rate of spontaneous preterm birth in each type of congenital uterine anomaly, and 2) to assess the performance of quantitative fetal fibronectin and cervical length measurement by transvaginal ultrasound in asymptomatic women with congenital uterine anomalies for the prediction of spontaneous preterm birth at <34 and <37 weeks of gestation. This was a retrospective cohort of women with congenital uterine anomalies asymptomatic for spontaneous preterm birth, from 4 tertiary referral centers in the United Kingdom (2001-2016). Congenital uterine anomalies were categorized into fusion (unicornuate, didelphic, and bicornuate uteri) or resorption defects (septate, with or without resection, and arcuate uteri), based on prepregnancy diagnosis. All women underwent serial transvaginal ultrasound cervical length assessment in the second trimester (16 to 24 weeks' gestation); a subgroup underwent quantitative fetal fibronectin testing from 18 weeks' gestation. We investigated the relationship between congenital uterine anomalies and predictive test performance for spontaneous preterm birth at <34 and <37 weeks' gestation. A total of 319 women were identified as having congenital uterine anomalies in our high-risk population. Of the women, 7% (23/319) delivered spontaneously at <34 weeks' gestation and 18% (56/319) at <37 weeks' gestation. Rates of spontaneous preterm birth by type were asfollows: 26% (7/27) for unicornuate, 21% (7/34) for didelphic, 16% (31/189) for bicornuate, 13% (7/56) for septate, and 31% (4/13) for arcuate. In all, 80% (45/56) of women who had spontaneous preterm birth at <37 weeks did not develop a short cervical length (<25 mm) during the surveillance period (16-24 weeks). The diagnostic accuracy of short cervical length had a low sensitivity (20.3) for predicting spontaneous preterm birth at <34 weeks. Cervical length had an area under the receiver operating curve of 0.56 (95% confidence interval, 0.48-0.64) and 0.59 (95% confidence interval, 0.55-0.64) for prediction of spontaneous preterm birth at <34 and <37 weeks, respectively. The area under the curve for cervical length to predict spontaneous preterm birth at <34 weeks was 0.48 for fusion defects (95% confidence interval, 0.39-0.57) but 0.78 (95% confidence interval, 0.66-0.91) for women with resorption defects. Overall quantitative fetal fibronectin had an area under the curve of 0.63 (95% confidence interval, 0.49-0.77) and 0.58 (95% confidence interval, 0.49- 0.68) for prediction of spontaneous preterm birth at <34 and <37 weeks, respectively. The area under the curve for prediction of spontaneous preterm birth at <37 weeks with quantitative fetal fibronectin for fusion defects was 0.52 (95% confidence interval, 0.41-0.63) but 0.79 (95% confidence interval, 0.63-0.95) for women with resorption defects. Results were similar when women with intervention were excluded. The commonly used markers cervical length and quantitative fetal fibronectin have utility in prediction of spontaneous preterm birth in resorption congenital uterine defects but not in fusion defects. This is contrary to findings in other high-risk populations. These findings need to be accounted for when planning antenatal care, and have potential implications for predictive tests used in spontaneous preterm birth surveillance and intervention.

Ultrasound Assessment of Cervical Length in the First Trimester of Pregnancy to Predict Preterm Birth

Ultrasound Assessment of Cervical Length in the First Trimester of Pregnancy to Predict Preterm Birth

P01.03: Ultrasound assessment of cervical length and volume: comparison of transabdominal and transvaginal approach

We investigate the reliability of transabdominal (TA) 3D measurements of the cervical volume (CV) by comparison with transvaginal sonography for CV measurement. All singleton pregnancies were included and women who already had a diagnosis of preterm labour, PROM, IIOC in the current pregnancy were excluded. For determination of the CV using VOCAL software. We assessed the correlation of TA and TV measurements. In addition, the discrepancies between TA and TV sonography were analysed to investigate the practical usefulness of TA sonography for the variable maternal and fetal conditions. A paired t test and Pearson correlation were used to compare the two parameters according to approach method. A total of 300 pregnant women were enrolled in this study. The mean GA was 33±3.6 years. The mean CL and CV were 34.5 ± 9.5 cm and 35.1 ± 12.9cm3 on TAS and 33.5 ± 9.7 cm and 35.1 ± 12.9cm3 on TVS, respectively. There was no significant difference between these means of CL and CV(Pearson r = 0.76 vs r=0.91, respectively). There are no significant discrepancy between TV and TA measurement of both parameter for the variable fetal and maternal condition; fetal presentation, maternal abdominal wall thickness, bladder filling state, maternal age, amniotic fluid index. Preterm birth group (N=16, 7.4%) had more shorter and smaller TV CL, CV(30.0 ± 12.1mm vs 34.0 ± 0.93mm, p 0.01 and 29.30 ± 9.3 cm3 vs 35.47 ± 13.14 cm3 p 0.03, respectively) than term birth group. CV measurement did not add any benefit compared with the CL measurement for prediction of preterm birth. But in subgroup analysis, CV measurement had additional benefit compared with the CL for prediction of preterm birth in normal cervical length group. In conclusion, the evidence for the clinical application of cervical volume screening is still insufficient. If TA CL is normal, it could be useful to try the TACV measurement. This step-by-step approach may be more convenient and useful to both patients and physicians for cervical length screening.

Transvaginal cervical length scans to prevent prematurity in twins: a randomized controlled trial

Twin pregnancies are associated with an increased risk of perinatal morbidity and mortality primarily due to spontaneous preterm deliveries. The mean gestational age for delivery is 35.3 weeks and twins account for 23% of preterm births <32 weeks. A number of strategies have been proposed to prevent preterm deliveries: tocolytics, bed rest, hospitalization, home uterine activity monitoring, cerclage, and most recently, progesterone. Unfortunately, none have proven effective. Recent metaanalyses and reviews suggest that transvaginal cervical length (TVCL) ultrasound in the second trimester is a powerful predictor of preterm birth among asymptomatic women. Indeed, TVCL has the highest positive and negative predictive values for determining the risk of spontaneous preterm delivery in twin pregnancies. It follows that TVCL assessment may allow identification of a subset of twin pregnancies that re better candidates for interventions intended to prevent prematurity. We sought to determine whether use of TVCL prolongs gestation in twin pregnancies. This is a multicenter, randomized, controlled trial of 125 dichorionic or monochorionic/diamniotic twin pregnancies without prior preterm birth <28 weeks. The study group (n = 63) had TVCL and digital exams monthly from 16-28 weeks and were managed with a standard algorithm for activity restriction and cerclage. The control group (n = 62) had monthly digital cervical examinations but no routine TVCL ultrasound examinations. The primary outcome was gestational age at delivery. Secondary outcomes included percentage of deliveries <35 weeks, and maternal and neonatal outcomes. The mean gestational age at delivery was 35.7 weeks (95% confidence interval [CI], 35.2-36.2) among those managed with TVCL and 35.5 weeks (95% CI, 34.7-36.4) among the control patients. The Kaplan-Meier estimates of deliveries <38 weeks were not significantly different between groups. This was true whether we compared curves with a log-rank test (P = .67), Breslow test (P = .67), or Tarone-Ware test (P = .64). The percentage of deliveries <35 0/7 weeks did not differ: 27.4% for subjects managed with routine TVCL and 28.6% for control subjects (relative risk, 0.96; 95% CI, 0.60-1.54). Our study had an 80% power to detect a 12-day difference in the gestational age at delivery with 95% confidence. The overall mean length of gestation and the percentage of women delivering <35 weeks did not differ between twin gestations managed with TVCL and digital exams monthly from 16-28 weeks with a standard algorithm for activity restriction and cerclage and controls who had monthly digital cervical examinations but no routine TVCL. Routine second-trimester transvaginal ultrasound assessment of cervical length is not associated with improved outcomes when incorporated into the standard management of otherwise low-risk twin pregnancies.

Cervical length measurement: Comparison of transabdominal and transvaginal approach.

Objective: To compare transabdominal (TA) and transvaginal (TV) ultrasound assessment of cervical length at 16–41 weeks gestation. Methods: TA and TV ultrasound measurements of cervical length were made on 491 pregnancies of 16–41 weeks gestation. Cervical length was measured from internal to external cervical os. Bland‐Altman plots and Wilcoxon signed rank test were used to evaluate differences between TA and TV measurements. Results: The validity of the TA method depended on cervical length. Although the TA method underestimated cervical length by 2.0 mm on average (P < 0.001), Bland Altman plots showed an inverse trend with shorter cervixes. In women with a cervix < 25 mm (n = 30) based on TV scan measurement, TA overestimated cervical length by 12 mm (P < 0.001). The sensitivity and specificity of TA as a test to detect cervical length < 25 mm were 10% (95% CI: 2.1–26%) and 94% (95% CI: 92–96%) respectively; the negative LR was 0.96 (95% CI: 0.84–1.08). The maximum area under the ROC curve would be obtained at a TA cut‐off = 32 mm (to detect a cervix < 25 mm), corresponding to a sensitivity of 77% and a specificity of 58%. Conclusion: TA measurements do not reflect TV assessment accurately, particularly if the cervix is short. At 24–34 weeks, a policy of proceeding to TV scan if TA measurement is < 25 mm will only detect 10% of affected pregnancies and has a poor positive predictive value so is of limited value as a predictive tool for women attending with symptoms and signs of preterm labour > 24 weeks gestation. There is no value in TA assessment of the cervix > 36 weeks.

PPO.55 Full dilatation caesarean section and risk of subsequent preterm birth: a case series

Preterm birth (PTB) or mid-trimester loss is rare following term pregnancy. Caesarean section carried out at full dilatation (FDCS) is associated with increased clinical challenges1. The integrity of the cervix...

Ultrasound Assessment of Cervical Length to Predict No Spontaneous Delivery Within 24 Hours at Term

Ultrasound Assessment of Cervical Length to Predict No Spontaneous Delivery Within 24 Hours at Term

Ultrasound assessment of cervical length at 18–21 weeks' gestation in an Australian obstetric population: Comparison of transabdominal and transvaginal approaches

Using a fixed cut-off of ≤25mm, ultrasound assessment of cervical length during the 18-23week anomaly scan has been shown to identify approximately 50% of pregnancies that would deliver prior to 34weeks. To determine whether a policy of reverting to transvaginal cervical assessment only if the cervix appears short (≤25mm) on transabdominal assessment affects the efficiency of screening. Women with a singleton pregnancy that presented for a routine anomaly scan had their cervical length assessed transabdominally, initially with the maternal bladder full (TABF) and then empty (TABE). Cervical length was then assessed transvaginally (TV). One hundred and ninety-eight women agreed to participate in the study. Identification of the internal and external cervical os was possible during TABF, TABE and TV sonography in 97.0, 82.8 and 100%, respectively. Compared with TV sonography, TABF overestimates cervical length (6.1mm difference in median values; P<0.01). There was no significant difference between TV and TABE. However, TABE assessment was not possible in one in six women. If TABF sonography was to be used as a screening tool and using ≤25mm as the critical cut-off, the sensitivity and specificity was 15.4 and 93.2%, respectively. This study has shown that assessment of cervical length using a TA approach is only routinely possible when the bladder is full. However, measurements are significantly overestimated. Therefore, we feel that TV assessment of cervical length is the preferred method of reliable cervical assessment. As such, all women should be offered a TV assessment of cervical length at the time of the fetal anomaly ultrasound as a screening test for preterm birth.

Cervical length measured by transvaginal ultrasonography and cervicovaginal infection as predictor of preterm birth risk.

Introduction:The study shows possibilities of transvaginal sonographic measurement of the cervix in prediction of premature birth risk.Goals:The aim of the study was to follow up the cervical length in the pregnant from 16th to 37th week, as well as to do a microbiological analysis of the vaginal and cervical flora and to identify relation between the cervical shortening and microbiological flora as well as with a premature birth.Material and methods:The investigation was conducted as a prospective study on two groups of female patients in Clinical Centre of Banja Luka. In the high risk group we had 8% of patients with cervical length bellow than 15mm, 30% of patients with cervical length from 15 to 25m and 62% of patients with cervical length bigger than 25mm. In the low risk group we had no patients with cervical length bellow 15mm, 95% of patients had cervical length bigger than 25mm and 5% of patients had cervical length from 15 do 25mm.Results:The regression coefficient of the cervical length in the high risk group was 0.44mm, while in the low risk group it was 0.26mm. In the high risk group 67.56% patients had a positive cervical smear finding, while in the low risk group it was 4%. A high premature birth (defined as birth before 36.6 weeks) incidence of 50% was presented in patients with cervical length bellow 15mm. In the group of patients with cervical length up to 25mm the premature risk incidence was 10.52±0.05. In the high risk group of patients with a positive cervical smear finding, regarding the cervical length the percentage was as follows; in the subgroup of 15mm length 88,89±11,87, in subgroup from 15 to 25mm was 62,07±11,43 and in the subgroup bigger than 25mm, 60.06±8.05.Conclusion:By the analysis of the first and second goal of our study we can conclude that ultrasound assessment of cervical length is simple and feasible in the 16th week of pregnancy in both groups, with high and low risk. The length of the cervix in this period is shorter in the high risk group compared with the low-risk group. This difference was not statistically significant, however, it clearly demonstrated connection between shorten length of the cervix with the preterm birth. A regression analysis shows that the shortening of the cervix length is more frequent in high risk group which is to be expected, bearing in mind that in this group, the risk of preterm delivery was significantly higher.

PF.47 Routine Cervical Assessment at Anomaly Scan May Reduce Neonatal Morbidity and Mortality Associated with Preterm Birth

A recent metaanalysis has suggested that measurement of the cervical length should be performed in conjunction with the anomaly scan (1). We decided to investigate if this recommendation is justifiable...

Improving the screening accuracy for preterm labor: is the combination of fetal fibronectin and cervical length in symptomatic patients a useful predictor of preterm birth? A systematic review

Our objective was to systematically review the current medical literature to assess the accuracy of the combination of fetal fibronectin (fFN) plus ultrasound assessment of cervical length (CL) as screening tools for preterm labor and prediction of preterm birth (PTB), and to compare this to the traditional clinical method of digital cervical examination. We searched PubMed and Cochrane databases without date restriction using the key words "fibronectin" and "cervical length," limited to human studies published in English. In all, 85 studies were identified and supplemented by 1 additional study found through bibliographic search. Nine studies reported the association between fFN positivity plus CL measurement with PTB in women presenting with symptomatic uterine contractions. We conducted an analytic review of the sensitivity, specificity, positive predictive value, and negative predictive value of fFN plus CL for PTB. Further metaanalysis was not performed due to study heterogeneity, especially with respect to the range of gestational ages and variations in cutoff values for the diagnosis of short cervix. Although the clinical diagnostic methodology of preterm labor diagnosis by documenting uterine contractions plus cervical change is currently standard practice, a newer approach combining fFN and CL screening results in a higher sensitivity and positive predictive value for PTB risk while maintaining high negative predictive value. We conclude that this combined screening approach yields useful information regarding short-term risks that can be used to guide acute management, and effectively identifies a population at low risk in whom expensive and potentially dangerous interventions could be avoided.

P30.11: Ultrasound assessment of cervical length in labour induction: prediction of maternal and perinatal outcome

To evaluate the usefulness of sonographic assessment of cervical length in the prediction of maternal and perinatal outcome at the beginning of labour induction. We performed a prospective cohort study of 165 inductions of labor. Indications of labor induction were prolonged pregnancy (53.9%), pre-eclampsia (13.3%), fetal growth restriction (10.9%), gestational diabetes (9.7%), and others (12.2%). When the Bishop score was below 6 at admission, cervical ripening with prostaglandins was performed. Membrane rupture and intravenous oxytocin was used in all cases. Maternal and perinatal variables were collected prospectively. Analisys was performed by logistic regression analysis and ROC curves. The rate of cesarean delivery after induction was 23.6%, 46.7% of patients were nulliparous, and 16.7% of patients had a history of previous cesarean section. Mean gestational age at the inclusion was 39.7(1.6) weeks. Ultrasound cervical length areas under the ROC curve for prediction of Cesarean section were 75% (95% CI 62–83%; P = 0.04), and for the prediction of severe maternal complication 83% (95% CI 74–92%; P = 0.007). Cervical length of 20 mm was the best cut-off for the prediction of cesarean after labor induction (92% sensitivity and 68% specificity). Patients with a cervical length < 20 mm at the beginning of labour induction had a lower rate of cesarean sections (10.7% vs. 33.7%; P = 0.018) (OR 0.19 (CI 95% 0.05–0.76; P = 0.02)) and cesarean section for failed induction (7.1% vs. 24.7%; P = 0.045) (OR 0.16 (CI 95% 0.03–0.75; P = 0.03)) and a trend to reduced neonatal admission rate (3.6% vs. 15.1%; P = 0.101), umbilical artery pH below 7.20 (7.4% vs. 17.4%; P = 0.184) and severe maternal complications (0% vs. 7%; P = 0.151). Ultrasonographic measurement of cervical length at labour induction admission predicts maternal and perinatal outcome and the risk of Cesarean section.