Self-reported pain scores as a predictor of preterm birth in symptomatic twin pregnancy: a retrospective study.

BACKGROUND: To evaluate the self-reported pain scores as a predictor of preterm birth (PTB) in symptomatic twin pregnancy and to develop a nomogram for the prediction model. METHODS: We conducted a retrospective study of 148 cases of symptomatic twin pregnancies before 34 weeks of gestation visited at Seoul national university hospital from 2013 to 2018. With other clinical factors, self-reported pain score was evaluated by the numerical rating scale (NRS) pain scores for pain intensity. By multivariate analyses and logistic regression, we developed a prediction model for PTB within 7 days. Using the Cox proportional hazards model, the curves were plotted to show the predictability of the PTB according to NRS pain score, while adjusting the other covariates. RESULTS: Twenty-three patients (15.5 %) delivered preterm within 7 days. By a logistic regression analysis, higher NRS pain score (OR 1.558, 95 % CI 1.093-2.221, P < 0.05), shorter cervical length (OR 3.164, 95 % CI 1.262-7.936, P < 0.05) and positive fibronectin results (OR 8.799, 95 % CI 1.101-70.330, P < 0.05) affect PTB within 7 days. Using the variables, the area under the receiver operating characteristic curve (AUROC) of the prediction model was 0.917. In addition, we developed a nomogram for the prediction of PTB within 7 days. CONCLUSIONS: Self-reported pain scores combined with cervical length and fetal fibronectin are useful in predicting impending PTB in symptomatic twin pregnancy.

Contribution of ultrasonography to the prediction of the induction-delivery interval: The ECOLDIA prospective multicenter cohort study.

INTRODUCTION: To evaluate the ability of preinduction ultrasonographic cervical length to predict the interval between induction and delivery in women at term with a Bishop score of 4 to 6 at induction. STUDY DESIGN: This multicenter prospective observational cohort recruited 334 women from April 2010 to March 2014. Inclusion criteria were women with singleton pregnancies at a gestational age ≥37 weeks, with no previous caesarean, a medical indication for induction of labor, and a Bishop score of 4, 5, or 6. All women underwent cervical assessment by both transvaginal ultrasound and digital examination (Bishop score). The induction protocol was standardized. The primary outcome measure was the induction-delivery interval. Hazard ratios (HR) and their 95% confidence intervals (95% CI) were used to assess potential predictors. RESULTS: Mean gestational age at induction was 40.1 weeks, 60.8% of the women were nulliparous, and the cesarean rate was 13.4%. The mean induction-delivery interval was 20.8 h (± 10.6). Delivery occurred within 24 h for 56.9% (n=190) of the women. An ultrasonographic cervical length measurement less than 25 mm (HR=1.50, 95% CI 1.18-1.91, P<0.01) and parity (HR=1.41, 95% CI 1.21-1.65, P<0.01) appeared to predict induction-delivery interval. The cervical length cutoff to reduce the induction-delivery interval was 25 mm. CONCLUSION: A cervical length cutoff of 25 mm was associated with shorter induction-delivery interval in women at term with a Bishop score of 4 to 6.

Development and external validation of a nomogram for predicting preterm birth at < 32 weeks in twin pregnancy.

The purpose of this study was to develop a dynamic model to predict the risk of spontaneous preterm birth at < 32 weeks in twin pregnancy. A retrospective clinical study of consecutively asymptomatic women with twin pregnancies from January 2017 to December 2019 in two tertiary medical centres was performed. Data from one centre were used to construct the model, and data from the other were used to evaluate the model. Data on maternal demographic characteristics, transvaginal cervical length and funnelling during 20-24 weeks were extracted. The prediction model was constructed with independent variables determined by multivariate logistic regression analyses. After applying specified exclusion criteria, an algorithm with maternal and biophysical factors was developed based on 88 twin pregnancies with a preterm birth < 32 weeks and 639 twin pregnancies with a delivery ≥ 32 weeks. It was then evaluated among 34 pregnancies with a preterm birth < 32 weeks and 252 pregnancies with a delivery ≥ 32 weeks in a second tertiary centre without specific training. The model reached a sensitivity of 80.00%, specificity of 88.17%, positive predictive value of 50.33% and negative predictive value of 96.71%; ROC characteristics proved that the model was superior to any single parameter with an AUC of 0.848 (all P < 0.005). We developed and validated a dynamic nomogram model to predict the individual probability of early preterm birth to better represent the complex aetiology of twin pregnancies and hopefully improve the prediction and indication of interventions.

The degree of cervical length shortening as a predictor of successful or failed labor induction.

OBJECTIVE: To evaluate whether the degree of cervical length change was associated with successful cervical dilatation during labor induction. MATERIALS AND METHODS: We conducted a secondary analysis of a prospective observational study of term singleton pregnant women who underwent labor inductions. Cases of Cesarean section due to fetal distress or maternal request during the first stage of labor were excluded. The enrolled women were categorized into two groups according to achievement of full cervical dilatation. The cervical length near induction and cervical length shortening over the last four weeks of pregnancy were compared between the two groups. A receiver operating characteristics (ROC) analysis was performed to evaluate the screening performance for failed cervical dilatation during labor induction. RESULTS: A total of 165 women were enrolled for the final analysis; of these, 145 (87.9%) women reached the second stage of labor and 20 (12.1%) women failed to achieve full cervical dilatation. Women who failed to achieve full cervical dilatation had a significantly longer cervical length near induction and less cervical length change over previous four weeks compared with women who achieved full cervical dilatation (P = 0.018 and 0.005, respectively). Multivariate analysis showed that cervical length >29 mm (odds ratios [OR], 4.15; 95% confidence interval [CI], 1.290-13.374, P = 0.017) and cervical length shortening â‰¦ 6 mm (OR, 5.87; 95% CI, 1.552-22.271, P = 0.009) were significantly associated with failed cervical dilatation after adjusting for birthweight and previous history of vaginal delivery. Cervical length shortening alone provided a better prediction of failed cervical dilatation than the combination of cervical length and shortening (sensitivity, 76.9%; specificity, 63.8%). CONCLUSION: The probability of failed cervical dilatation during labor induction was significantly increased in cases when the cervical length was greater than 29 mm near induction or when the cervical length shortening was less than 6 mm over the last four weeks.

Change in cervical length after arrested preterm labor and risk of preterm birth.

OBJECTIVE: To assess the association between preterm birth and cervical length after arrested preterm labor in high-risk pregnant women. METHODS: In this post-hoc analysis of a randomized clinical trial, transvaginal cervical length was measured in women whose contractions had ceased 48 h after admission for threatened preterm labor. At admission, women were defined as having a high risk of preterm birth based on a cervical length of < 15 mm or a cervical length of 15-30 mm with a positive fetal fibronectin test. Logistic regression analysis was used to investigate the association of cervical length measured at least 48 h after admission and of the change in cervical length between admission and at least 48 h later, with preterm birth before 34 weeks' gestation and delivery within 7 days after admission. RESULTS: A total of 164 women were included in the analysis. Women whose cervical length increased between admission for threatened preterm labor and 48 h later (32%; n = 53) were found to have a lower risk of preterm birth before 34 weeks compared with women whose cervical length did not change (adjusted odds ratio (aOR), 0.24 (95% CI, 0.09-0.69)). The risk in women with a decrease in cervical length between the two timepoints was not different from that in women with no change in cervical length (aOR, 1.45 (95% CI, 0.62-3.41)). Moreover, greater absolute cervical length after 48 h was associated with a lower risk of preterm birth before 34 weeks (aOR, 0.90 (95% CI, 0.84-0.96)) and delivery within 7 days after admission (aOR, 0.91 (95% CI, 0.82-1.02)). Sensitivity analysis in women randomized to receive no intervention showed comparable results. CONCLUSION: Our study suggests that the risk of preterm birth before 34 weeks is lower in women whose cervical length increases between admission for threatened preterm labor and at least 48 h later when contractions had ceased compared with women in whom cervical length does not change or decreases. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Measurement of the uterocervical angle for the prediction of preterm birth in symptomatic women.

PURPOSE: To examine if the uterocervical angle (UCA) can be used to predict preterm delivery in women with painful and regular uterine contractions and a cervical length of 25 mm or less. METHODS: Retrospective study at the perinatal unit of the University Hospital of Tuebingen, Germany. Women with singleton gestation and preterm contractions between 24 + 0 and 33 + 6 weeks' gestation were included. For the UCA measurement, a line is placed from the internal os to the external os irrespective of whether the cervix is straight or curved. A second line is drawn to delineate the lower uterine segment. The angle between the two lines is the UCA measurement. The measurements were taken on stored images from our database. RESULTS: The study consisted of 213 singleton pregnancies. At the time of UCA measurement, median maternal and gestational age was 31.4 years and 29.7 weeks' gestation. Median gestational age at delivery was 35.3 weeks and the corresponding birth weight 2480 g, respectively. The UCA measurement in women who delivered within 2 days, between 3-7 days and after 7 days was not helpful to distinguish between these three groups [median UCA measurements: 108.5°, 108.0° and 107.3° (Kruskal-Wallis test p = 0.576)]. Uni- and multivariate logistic multiple regression analysis demonstrated that the delivery within 2 days was only dependent on the gestational age and the cervical length at the time of presentation. CONCLUSION: The measurement of UCA is not useful in predicting preterm birth in the subsequent 7 days after an episode of preterm contractions.

Predictive factors of labour onset using ultrasonography.

We analysed the effectiveness of transvaginal ultrasonographic and foetal/maternal pulse Doppler findings as predictors of labour onset within 1 week. We included 22 single normal pregnancies and evaluated the one-point and short- and long-term differences in uterine artery pulsatility index (PI), umbilical artery PI, middle cerebral artery PI (MCA-PI), peak systolic velocity, and cervical length (CL). Presence of funnelling and membrane separation over the internal cervical os was evaluated. Significant changes were observed in the one-point measurement of and short-term and long-term differences in CL, the one-point measurement of and long-term difference in MCA-PI, and the presence of membrane separation (Grade 2). In multivariate analysis, the significant predictors were short-term differences in CL (odds ratio [OR]: 5.27), long-term differences in MCA-PI (OR: 13.3), and presence of membrane separation (Grade 2) (OR: 5.38). Transvaginal ultrasonographic and foetal pulse Doppler findings were effective predictors of labour onset within 1 week.Impact statementWhat is already known on this subject? Parameters reported to predict labour onset include the Bishop score, cervical length, decreased long-term cervical length, funnelling of the internal cervical os, and adrenal gland volume.What do the results of this study add? Short-term changes in cervical length, long-term changes in middle cerebral artery pulsatility index, and the presence of membrane separation Grade 2 were found to be useful predictive factors of labour onset in this study.What are the implications of these findings for clinical practice and/or further research? The prediction of labour onset enables clinicians to properly manage pregnancy and delivery considering maternal and foetal conditions.

Personalized assessment of cervical length improves prediction of spontaneous preterm birth: a standard and a percentile calculator.

BACKGROUND: A sonographic short cervix (length <25 mm during midgestation) is the most powerful predictor of preterm birth. Current clinical practice assumes that the same cervical length cutoff value should apply to all women when screening for spontaneous preterm birth, yet this approach may be suboptimal. OBJECTIVE: This study aimed to (1) create a customized cervical length standard that considers relevant maternal characteristics and gestational age at sonographic examination and (2) assess whether the customization of cervical length evaluation improves the prediction of spontaneous preterm birth. STUDY DESIGN: This retrospective analysis comprises a cohort of 7826 pregnant women enrolled in a longitudinal protocol between January 2006 and April 2017 at the Detroit Medical Center. Study participants met the following inclusion criteria: singleton pregnancy, ≥1 transvaginal sonographic measurements of the cervix, delivery after 20 weeks of gestation, and available relevant demographics and obstetrical history information. Data from women without a history of preterm birth or cervical surgery who delivered at term without progesterone treatment (N=5188) were used to create a customized standard of cervical length. The prediction of the primary outcome, spontaneous preterm birth at <37 weeks of gestation, was assessed in a subset of pregnancies (N=7336) that excluded cases with induced labor before 37 weeks of gestation. Area under the receiver operating characteristic curve and sensitivity at a fixed false-positive rate were calculated for screening at 20 to 23 6/7, 24 to 27 6/7, 28 to 31 6/7, and 32 to 35 6/7 weeks of gestation in asymptomatic patients. Survival analysis was used to determine which method is better at predicting imminent delivery among symptomatic women. RESULTS: The median cervical length remained fundamentally unchanged until 20 weeks of gestation and subsequently decreased nonlinearly with advancing gestational age among women who delivered at term. The effects of parity and maternal weight and height on the cervical length were dependent on the gestational age at ultrasound examination (interaction, P<.05 for all). Parous women had a longer cervix than nulliparous women, and the difference increased with advancing gestation after adjusting for maternal weight and height. Similarly, maternal weight was nonlinearly associated with a longer cervix, and the effect was greater later in gestation. The sensitivity at a 10% false-positive rate for prediction of spontaneous preterm birth at <37 weeks of gestation by a short cervix ranged from 29% to 40% throughout pregnancy, yet it increased to 50%, 50%, 53%, and 54% at 20 to 23 6/7, 24 to 27 6/7, 28 to 31 6/7, and 32 to 35 6/7 weeks of gestation, respectively, for a low, customized percentile (McNemar test, P<.001 for all). When a cervical length <25 mm was compared to the customized screening at 20 to 23 6/7 weeks of gestation by using a customized percentile cutoff value that ensured the same negative likelihood ratio for both screening methods, the customized approach had a significantly higher (about double) positive likelihood ratio in predicting spontaneous preterm birth at <33, <34, <35, <36, and <37 weeks of gestation. Among symptomatic women, the difference in survival between women with a customized cervical length percentile of ≥10th and those with a customized cervical length percentile of <10th was greater than the difference in survival between women with a cervical length ≥25 mm and those with a cervical length <25 mm. CONCLUSION: Compared to the use of a cervical length <25 mm, a customized cervical length assessment (1) identifies more women at risk of spontaneous preterm birth and (2) improves the distinction between patients at risk for impending preterm birth in those who have an episode of preterm labor.

Distribution of uterocervical angles in the second trimester of pregnant women at low risk for preterm delivery.

The uterocervical angle (UCA) has recently been studied as a parameter to identify women at risk for spontaneous preterm birth (sPTB). This study aimed to investigate the distribution of UCA values by transvaginal sonography (TVS) in the second trimester of women at low risk for sPTB. TVS was performed in 450 low-risk pregnant women at gestational age (GA) 160/7-240/7 weeks. The UCA distribution by GA was visualised using a scatter plot. The range of UCA values and their relationship with GA were assessed using quantile regression analysis. p < .05 was considered statistically significant. A total of 242 participants with anteflexed uterus, no history of caesarean section and term delivery were analysed. The normal range of UCA (5th and 95th percentiles) was from 63.0 degrees (95% CI, 53.1-72.9) to 148.8 degrees (95% CI, 139.5-158.0) with no significant changes during this GA period (-0.3 degrees per week, p = .757).Impact statementWhat is already known on this subject? Spontaneous preterm birth (sPTB) is a major problem in obstetrics. A screening strategy using history of sPTB and cervical length (CL) measurement is the current standard to identify women at risk for sPTB and provide adequate prevention. However, a third of women who are identified as low risk go on to have sPTB, so a better means needs to be found to more reliably identify women at risk. Various studies have found that a wide uterocervical angle (UCA) was associated with sPTB, and thus the UCA has been proposed as a potential sPTB screening parameter. However, to date there is a lack of prospective studies evaluating this proposal, and no consensus about the proper gestational age to perform UCA measurements to identify women at risk of sPTB.What do the results of this study add? This study reports the distribution of UCA at the GA of 160/7-240/7 weeks of low-risk singleton pregnancy women who delivered at term. The mid-90% values ranged from 63.0 degrees to 148.8 degrees with no significant differences in this GA period.What are the implications of these findings for clinical practice and/or further research? Because of the wide range of UCA values at GA 160/7-240/7 weeks, more studies regarding UCA values in various gestational ages are required to fully understand the trend of UCA values along pregnancy and confirm whether or not the UCA would be a useful parameter for sPTB prediction and if so at what gestational age it would have to be assessed.

The influence of race on cervical length in pregnant women in Brazil.

OBJECTIVES: Short cervical length is a predictor of preterm birth. We evaluated if there were racial differences in variables associated with cervical length in pregnant Brazilian women. METHODS: Cervical length was determined by vaginal ultrasound in 414 women at 21 weeks gestation. All women were seen at the same clinic and analyzed by the same investigators. Women found to have a short cervix (≤25 mm) received vaginal progesterone throughout gestation. Composition of the vaginal microbiome was determined by analysis of the V1-V3 region of the gene coding for bacterial 16S ribosomal RNA. Demographic, clinical and outcome variables were determined by chart review. Subjects were 53.4% White, 37.2% mixed race and 9.4% Black. RESULTS: Pregnancy, medical history and education level were similar in all groups. Mean cervical length was shorter in Black women (28.4 mm) than in White (32.4 mm) or mixed race (32.8 mm) women (p≤0.016) as was the percentage of women with a short cervix (23.1, 12.2, 7.8% in Black, White, mixed race respectively) (p≤0.026). Mean cervical length increased with maternal age in White (p=0.001) and mixed race (p=0.045) women but not Black women. There were no differences in bacterial dominance in the vaginal microbiota between groups. Most women with a short cervix delivered at term. CONCLUSIONS: We conclude that Black women in Brazil have a shorter cervical length than White or mixed race women independent of maternal age, pregnancy and demographic history or composition of the vaginal microbiome.

Women's obstetric history and midtrimester cervical length measurements by 2d/3d and doppler ultrasound / História obstétrica e medida do comprimento do colo uterino de mulheres no segundo trimestre gestacional por ultrassonografia bi/tridimensional e Doppler

Abstract Objective The aim of the present study was to compare the obstetric history and both two- and tri-dimensional ultrasound parameters according to different cervical lengths. Methods The present cross-sectional study analyzed 248 midtrimester pregnant women according to cervical length and compared the data with the obstetric history and 2D/3D ultrasound parameters. Patients were divided into 3 groups according to cervical length: The Short Cervix group for cervical lengths ≥ 15mm and< 25mm(n= 68), the Very Short Cervix group for cervical lengths< 15mm (n = 18) and the Control group, composed of 162 pregnant women with uterine cervical lengths ≥ 25mm. Results When analyzing the obstetric history of only non-nulliparous patients, a significant association between the presence of a short cervix in the current pregnancy and at least one previous preterm birth was reported (p = 0.021). Cervical length and volume were positively correlated (Pearson coefficient = 0.587, p < 0.0001). The flow index (FI) parameter of cervical vascularization was significantly different between the Control and Very Short Cervix groups. However, after linear regression, in the presence of volume information, we found no association between the groups and FI. Uterine artery Doppler was also not related to cervical shortening. Conclusion The present study showed a significant association between the presence of a short cervix in the current pregnancy and at least one previous preterm birth. None of the vascularization indexes correlate with cervical length as an independent parameter. Uterine artery Doppler findings do not correlate with cervical length.

Resumo Objetivo O objetivo do presente estudo foi comparar a história obstétrica e os parâmetros bi- e tridimensionais ultrassonográficos de acordo com os diferentes comprimentos cervicais. Métodos O presente estudo transversal analisou 248 gestantes no segundo trimestre de acordo com o comprimento cervical e comparou os dados com a história obstétrica e os parâmetros ultrassonográficos 2D/3D. As pacientes foram divididas em 3 grupos de acordo com o comprimento do colo uterino: grupo Colo Curto para comprimentos cervicais ≥ 15mm e < 25mm (n = 68), grupo Colo Muito Curto para comprimentos cervicais < 15mm (n = 18) e grupo Controle, composto por 162 gestantes com comprimento cervical uterino ≥ 25 mm. Resultados Ao analisar a história obstétrica apenas de pacientes não nulíparas, foi relatadauma associação significativa entre a presença de colo uterino curto na gravidez atual e pelo menos um episódio de parto prematuro anterior (p = 0,021). Comprimento e volume do colo uterino foram correlacionados positivamente (coeficiente de Pearson = 0,587, p < 0,0001). O parâmetro índice de fluxo (IF) da vascularização cervical foi significativamente diferente entre os grupos Controle e Colo Muito Curto. Entretanto, após regressão linear, na presença de informações de volume, não encontramos associação entre os grupos e o parâmetro IF. Também não foi encontrada relação entre o Doppler da artéria uterina e o encurtamento cervical. Conclusão O presente estudo mostrou uma associação significativa entre a presença de colo uterino curto na gravidez atual e pelo menos um episódio de parto prematuro anterior. Nenhum dos índices de vascularização se correlaciona com o comprimento cervical como parâmetro independente, assim como o Doppler da artéria uterina também não está relacionado ao comprimento do colo uterino.

Women's Obstetric History and Midtrimester Cervical Length Measurements by 2D/3D and Doppler Ultrasound.

OBJECTIVE: The aim of the present study was to compare the obstetric history and both two- and tri-dimensional ultrasound parameters according to different cervical lengths. METHODS: The present cross-sectional study analyzed 248 midtrimester pregnant women according to cervical length and compared the data with the obstetric history and 2D/3D ultrasound parameters. Patients were divided into 3 groups according to cervical length: The Short Cervix group for cervical lengths ≥ 15 mm and < 25 mm (n = 68), the Very Short Cervix group for cervical lengths < 15 mm (n = 18) and the Control group, composed of 162 pregnant women with uterine cervical lengths ≥ 25 mm. RESULTS: When analyzing the obstetric history of only non-nulliparous patients, a significant association between the presence of a short cervix in the current pregnancy and at least one previous preterm birth was reported (p = 0.021). Cervical length and volume were positively correlated (Pearson coefficient = 0.587, p < 0.0001). The flow index (FI) parameter of cervical vascularization was significantly different between the Control and Very Short Cervix groups. However, after linear regression, in the presence of volume information, we found no association between the groups and FI. Uterine artery Doppler was also not related to cervical shortening. CONCLUSION: The present study showed a significant association between the presence of a short cervix in the current pregnancy and at least one previous preterm birth. None of the vascularization indexes correlate with cervical length as an independent parameter. Uterine artery Doppler findings do not correlate with cervical length.

OBJETIVO: O objetivo do presente estudo foi comparar a história obstétrica e os parâmetros bi- e tridimensionais ultrassonográficos de acordo com os diferentes comprimentos cervicais. MéTODOS: O presente estudo transversal analisou 248 gestantes no segundo trimestre de acordo com o comprimento cervical e comparou os dados com a história obstétrica e os parâmetros ultrassonográficos 2D/3D. As pacientes foram divididas em 3 grupos de acordo com o comprimento do colo uterino: grupo Colo Curto para comprimentos cervicais ≥ 15 mm e < 25 mm (n = 68), grupo Colo Muito Curto para comprimentos cervicais < 15 mm (n = 18) e grupo Controle, composto por 162 gestantes com comprimento cervical uterino ≥ 25 mm. RESULTADOS: Ao analisar a história obstétrica apenas de pacientes não nulíparas, foi relatada uma associação significativa entre a presença de colo uterino curto na gravidez atual e pelo menos um episódio de parto prematuro anterior (p = 0,021). Comprimento e volume do colo uterino foram correlacionados positivamente (coeficiente de Pearson = 0,587, p < 0,0001). O parâmetro índice de fluxo (IF) da vascularização cervical foi significativamente diferente entre os grupos Controle e Colo Muito Curto. Entretanto, após regressão linear, na presença de informações de volume, não encontramos associação entre os grupos e o parâmetro IF. Também não foi encontrada relação entre o Doppler da artéria uterina e o encurtamento cervical. CONCLUSãO: O presente estudo mostrou uma associação significativa entre a presença de colo uterino curto na gravidez atual e pelo menos um episódio de parto prematuro anterior. Nenhum dos índices de vascularização se correlaciona com o comprimento cervical como parâmetro independente, assim como o Doppler da artéria uterina também não está relacionado ao comprimento do colo uterino.

Is asymptomatic bacteriuria associated with short cervical length in women with a singleton pregnancy, a secondary analysis of two national cohort studies with small embedded randomized controlled trials.

OBJECTIVE: To assess the association between asymptomatic bacteriuria (ASB) and short cervical length (CL), since they are both associated with preterm delivery. STUDY DESIGN: In two prospective multicentre cohort studies, pregnant women were screened for the presence of ASB and short CL (≤25 mm). We compared CL in women with and without ASB. Both studies had a small randomised clinical trial embedded. RESULTS: Our study population comprised 1 610 women, of whom 114 were ASB positive. Median cervical length was similar in women with and without ASB (44.0 vs 44.0 mm, P = 0.60). More women in the ASB positive group had a short CL compared to the ASB negative group (1.8 % versus 0.4 %, P = 0.047)). The gestational age at delivery did not differ between the groups (ranging from 38 + 3 in women with ASB and short CL to 39 + 5 in women without ASB with a short CL P = 0.52). No preterm births occurred in women with a short cervical length (regardless of ASB status). In the women without ASB and no short CL 4.8 % had a preterm birth, in the women with ASB but not a short CL 4.1 % had a preterm birth. CONCLUSION: While ASB status did not influence median cervical length, we found a significant relationship between a short CL and ASB positive women. We found no statistical significant difference on the preterm birth rate and mean gestational age.

Intraobserver and interobserver variability in first-trimester transvaginal ultrasound cervical length.

Objectives: To determine intraobserver and interobserver variability in the measurement of different cervical length (CL) components at the first trimester (endocervical canal and isthmus), describe the optimum measurement method (single line or two lines) and establish a normality curve of first trimester CL in our population.Methods: Women who attended the first-trimester US scan, between 11.0 and 13.6 weeks of gestation at Vall d'Hebron Universitary Hospital, Barcelona, Spain were included. Inclusion criteria were singleton pregnancies in women over 18 years of age, no gestational complications, uterine malformations or uterine surgery. Lengths of the endocervical canal and uterine isthmus were measured using two methods.Results: Both methods for endocervical canal measurement, single line and two lines, showed low intraobserver variability between examiners, with no statistical differences in the majority of measurements. A correct correlation existed between examiners using the single-line two-line measurements, with a concordance correlation coefficient of 0.76.Conclusions: Cervical length in the first trimester was reproducible for the same physician and between different physicians; however, it is essential to ensure examiners receive adequate training in the technique.

Predictive Value of Midtrimester Universal Cervical Length Screening Based on Parity.

OBJECTIVES: To evaluate the effect of parity on performance characteristics of midtrimester cervical length (CL) in predicting spontaneous preterm birth (sPTB) before 37 weeks. METHODS: This was a retrospective cohort study of 13,508 women with no history of sPTB undergoing universal transvaginal CL screening at 17 to 23 weeks' gestation from 2011 to 2016. Patients who declined screening or with unknown delivery outcomes were excluded. Areas under the receiver operator characteristic curves were used to assess and compare the predictive ability of CL screening for sPTB. The sensitivity, specificity, and positive and negative predictive values were estimated for specific CL cutoffs for prediction of sPTB. RESULTS: There were 20,100 patients, of whom 2087 (10%) declined screening and 4505 (22%) did not meet inclusion criteria. Of the remaining 13,508 patients, 43% were nulliparous. The incidence rates of sPTB were 6.5% in nulliparas and 4.9% in multiparas (P < .001). The mean CLs were 39.9 mm in nulliparas and 41.8 mm in multiparas (P < .001), and those of the first percentiles were 19.0 mm in nulliparas and 24.0 mm in multiparas. Cervical length was significantly more predictive of sPTB in nulliparas (area under the curve, 0.67; 95% confidence interval, 0.63-0.70; versus 0.61, 95% confidence interval, 0.57-0.63; P = .008). At CL cutoffs of 10, 15, 20, and 25 mm or less, the sensitivity was lower in multiparas, and the specificity was comparable between the groups. CONCLUSIONS: Midtrimester CL is less predictive of sPTB in multiparas compared to nulliparas. The poor predictive ability, especially in multiparas, calls into question the value of universal CL screening in this population.

Single and repeat cervical-length measurement in twin gestation with threatened preterm labor.

OBJECTIVE: To examine the effectiveness of single and repeat sonographic cervical-length (CL) measurement in predicting preterm delivery in symptomatic women with a twin pregnancy. METHODS: This was a retrospective study of women with a twin gestation who presented with painful and regular uterine contractions at 24 + 0 to 33 + 6 weeks' gestation at the perinatal unit of the University Hospital of Tübingen, Tübingen, Germany between 2012 and 2018. CL was measured on transvaginal ultrasound at the time of admission and a few days later after cessation of contractions. Treatment included administration of tocolytics (usually oral nifedipine), for no more than 48 h, and administration of steroids if CL was ≤ 25 mm. Patients were clustered into five groups according to the CL measurement obtained at first assessment: < 10.0 mm; between 10.0 and 14.9 mm; between 15.0 and 19.9 mm; between 20.0 and 24.9 mm; and ≥ 25.0 mm. For each group, we calculated the test performance of CL measurement for prediction of preterm delivery within the subsequent 7 days and before 34 weeks' gestation. Regression analysis was used to evaluate the test performance of the second CL measurement for predicting preterm delivery within 7 days after the second assessment. RESULTS: The study population consisted of 257 twin pregnancies, of which 80.2% were dichorionic diamniotic. Median maternal and gestational ages at the time of admission were 32.0 years and 29.9 weeks' gestation, respectively. Preterm birth within 7 days of admission occurred in 23 (8.9%) pregnancies, and 82 (31.9%) patients delivered prior to 34 weeks' gestation. Median CL for the entire study population was 17.0 mm. Delivery within 7 days after the first assessment occurred in 29.0%, 10.6%, 4.2%, 6.3% and 0% of women with CL < 10.0 mm, 10.0-14.9 mm, 15.0-19.9 mm, 20.0-24.9 mm and ≥ 25.0 mm, respectively. There was a weak, but significant, association between the CL measurement at the time of admission and the time interval between admission and delivery (interval = 27.9 + 0.58 × CL; P = 0.003, r = 0.184). CL was measured again after a median time interval of 3 (interquartile range (IQR), 2-5) days in 248 cases. Median second CL measurement was 17.0 (IQR, 11.5-22.0) mm. Delivery occurred within the subsequent 7 days after the second measurement in 25/248 (10.1%) cases. Binary regression analysis indicated that the first (odds ratio (OR), 0.895; P = 0.003) and second (OR, 0.908; P = 0.002) CL measurements, but not the difference between the two measurements (OR, 0.961; P = 0.361), were associated significantly with delivery within 7 days after the second measurement. Receiver-operating-characteristics (ROC)-curve analysis for the prediction of delivery within 7 days after the second assessment did not show a significant difference between the predictive performance of the first (area under ROC curve (AUC), 0.676 (95% CI, 0.559-0.793)) and the second (AUC, 0.661 (95% CI, 0.531-0.790)) measurement. CONCLUSION: Sonographic measurement of CL can be helpful in predicting preterm delivery within 7 days of presentation in symptomatic women with a twin gestation; however, the test performance is relatively weak. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Cervical shear wave elastography as a predictor of preterm delivery during 18-24 weeks of pregnancy.

AIM: The aim of this study was to compare shear wave cervical elasticity between term and preterm delivery group. METHODS: A prospective cohort study was conducted in enrolled 158 pregnant women at 18-24 weeks of gestation who come for second trimester scan consecutively. Transvaginal ultrasonography for cervical length as well as cervical elasticity in five regions of interest was performed. Intraobserver and interobserver reproducibility were evaluated. Gestational age at deliveries was followed, and cervical shear wave elasticity between term and preterm group was compared. RESULTS: A total of 158 pregnant women were enrolled in this study while 120 pregnancies data were collected for subsequent analysis, 10 pregnancies spontaneously delivered during the preterm period and 110 pregnancies delivered at term. Intraobserver and interobserver reproducibility were high; however, cervical shear wave elasticity in both groups were not significantly different (external anterior lip 2.29 ± 0.66 and 2.45 ± 0.58 m/s, P value 0.30, internal anterior lip 2.74 ± 0.96 and 2.80 ± 0.61 m/s, P value 0.83). Nonsignificant correlations of cervical shear wave elasticity with gestational age and cervical length (r = -0.1 and r = 0.02, respectively) were demonstrated. CONCLUSION: Cervical shear wave elasticity in preterm and term groups was not significantly different when measured at 18-24 weeks of gestation. There are nonsignificant correlations between cervical shear wave elasticity, gestational age and cervical length. Cervical shear wave elastography alone should not be used as a predictor for preterm delivery.

HIV serostatus, viral load, and midtrimester cervical length in a Zambian prenatal cohort.

OBJECTIVE: To evaluate whether maternal HIV serostatus and plasma viral load (VL) are associated with midtrimester cervical length (CL). METHODS: The Zambian Preterm Birth Prevention Study (ZAPPS) is an ongoing prospective cohort that began enrolling in Lusaka in August 2015. Pregnant women undergo ultrasound to determine gestational age and return for CL measurement at 16-28 weeks. We evaluated crude and adjusted associations between dichotomous indicators and short cervix (≤2.5 cm) via logistic regression, and between VL and CL as a continuous variable via linear regression. RESULTS: This analysis includes 1171 women enrolled between August 2015 and September 2017. Of 294 (25.1%) HIV-positive women, 275 (93.5%) had viral load performed close to CL measurement; of these, 148 (53.8%) had undetectable virus. Median CL was 3.6 cm (IQR 3.5-4.0) and was similar in HIV-infected (3.7 cm, IQR 3.5-4.0) versus uninfected (3.6 cm, IQR 3.5-4.0) participants (P=0.273). The odds of short CL were similar by HIV serostatus (OR 0.64; P=0.298) and detectable VL among those infected (OR 2.37, P=0.323). We observed no association between log VL and CL via linear regression (-0.12 cm; P=0.732). CONCLUSION: We found no evidence of association between HIV infection and short CL.

Twin transvaginal cervical length at 16-20 weeks and prediction of preterm birth.

OBJECTIVE: Our objective was to determine if transvaginal cervical length at 16-20 weeks is predictive of preterm birth <34 weeks in a large cohort of twin pregnancies. STUDY DESIGN: This is a secondary analysis from a randomized trial of 17 alpha-hydroxyprogesterone caproate in twins to prevent preterm birth. Transvaginal cervical length was performed at 16-20-week gestation. The inclusion criteria were non-anomalous twins with transvaginal cervical length at 16-20 weeks. Receiver-operating characteristic (ROC) curves were generated to determine the transvaginal cervical length associated with preterm birth. RESULTS: Of 655 pregnancies, 27% (N = 178) women met our inclusion criteria. The rate of spontaneous preterm birth before 34 weeks was 16% (N = 29). A receiver operator characteristic curve was generated for all preterm birth <34 weeks (spontaneous and indicated) which demonstrated an area under the curve of 0.51, 95% CI (0.41-0.61). When indicated preterm birth (n = 15) were excluded, the area under the curve was 0.59 (95% CI 0.47-0.70), indicating that transvaginal cervical length values were not a clinically useful test for the prediction of spontaneous preterm birth. A transvaginal cervical length of 30 mm from this model would produce a sensitivity of detecting spontaneous preterm birth of 95% and a specificity of 14%. CONCLUSION: In an asymptomatic twin population, a single transvaginal cervical length between 16 and 20 weeks was not predictive of spontaneous preterm birth before 34 weeks. Thus, our findings suggest that routine transvaginal cervical length screening of twins should not be performed between 16-20 weeks.

Cervical pathways for racial disparities in preterm births: the Preterm Prediction Study.

Purpose: Racial disparities in preterm birth have been long recognized, but the social and biological mechanisms for these differences are unclear. Our analysis had three goals: (1) to determine the relation between race and other social risk factors and cervical structure; (2) to determine whether social factors mediate the relation between race and cervical structure; and (3) to determine whether racial disparities in preterm birth (PTB) are mediated through changes in cervical structure observed earlier in pregnancy. Materials and methods: Data from the Maternal Fetal Medicine Unit network Preterm Prediction Study were used to examine the relation between race and other social factors and cervical properties throughout pregnancy in 2920 black and white women. Outcomes included cervical length and dilation; cervical score (cervical length-internal dilation); and whether membranes protruded at 22-24 and 26-29 weeks. Race, education, income, insurance type, and marital status were examined as predictors of the outcomes using linear and logistic regression, adjusting for age, BMI, parity, and smoking. Mediation analysis was used to examine whether (a) any social factors explained racial differences in cervical properties, and (b) whether cervical properties mediated racial differences in risk for preterm birth. Results: Shorter cervical length, especially at a subject's first visit, was associated with black race (adjusted beta -1.56 mm, p < .01) and lower income (adjusted beta -1.48, p =.05). External dilation was not associated with social factors, while internal dilation was associated with black race and lower education. Black race and marital status were associated with lower cervical score. There was no evidence of mediation of the racial effect on cervical properties by any social factor. Shorter cervical length, dilation, and score were all associated with preterm birth (p < .01). Mediation analysis indicated that each of these mediated the effect of race, but explained a small proportion of the total effect (15-25%). Conclusions: Race, and, to a lesser extent, other social factors are correlated with adverse cervical properties. This pathway could explain a proportion of the racial disparity in preterm birth.