Transvaginal Cervical Length Measurement Research Articles

Comparing transabdominal and transvaginal cervical length measurements at mid‐trimester fetal anomaly scan: The impact of bladder fullness and lower uterine contractions

Comparing transabdominal and transvaginal cervical length measurements at mid‐trimester fetal anomaly scan: The impact of bladder fullness and lower uterine contractions

Introduction of universal transvaginal cervical length measurement does not decrease spontaneous preterm delivery rate compared to universal transabdominal screening with reflex cut‐off: A pre‐post study

AbstractObjectivesThe objective of our study is to examine cervical length measurements, identification of short cervix, vaginal progesterone use, and rate of spontaneous preterm delivery before and after departmental transition to a universal transvaginal ultrasound screening protocol from a universal transabdominal screening protocol.MethodsThis is a retrospective observational pre–post study examining the year prior to and year following a transition to a universal transvaginal ultrasound screening protocol to assess cervical length at the time of the anatomy survey. Prior to this transition, universal transabdominal cervical length screening was performed, with reflex transvaginal ultrasound measurement if transabdominal measurement was <35 mm or was unable to be obtained.ResultsA total of 1760 charts were reviewed; 962 charts were from the pre‐transition/transabdominal year and 798 charts were from the post‐transition/transvaginal year. In the post‐transition/transvaginal year, cervical length less than 20 mm was identified in 1.5% of cases, compared to 0.7% of cases in the pre‐transition/transabdominal year (p = 0.114). There was no difference in the rate of spontaneous preterm delivery between the two groups (5.1% in the pre‐transition/transabdominal year vs. 6.9% in the post‐transition/transvaginal year; p = 0.111).ConclusionsIn this pre‐post study, introduction of a universal transvaginal cervical length screening did not decrease spontaneous preterm delivery rates or detection of short cervix <20 mm, compared to a protocol of universal transabdominal cervical length screening with reflex to transvaginal for measurement <35 mm.

The Impact of Maternal BMI on Time of Transvaginal Cervical Imaging

Introduction: Ultrasound is an integral part of obstetrical care and obesity has been shown to decrease the accuracy of ultrasound examination in high-risk pregnancy (Tsai et al, 2015). Obesity decreases the fidelity of ultrasound, as decreased visualization is seen with increasing depth of abdominal adipose tissue (Paladini, 2009). While maternal obesity has been shown to detrimentally impact anatomical ultrasound, the effects of obesity on the performance of transvaginal ultrasound are unclear. Our aim was to evaluate if obesity has an effect on the time required to obtain transvaginal cervical length. Methods: Retrospective chart review between January 2016-January 2022 identified patients with cervical shortening (<2.5 cm) at the time of mid-trimester anatomical ultrasound scans. Scans were performed at the Maternal Fetal Medicine Department at Promedica Toledo Hospital between 16- and 24-weeks gestation. Patient BMI was recorded at the time of ultrasound and divided into obese (BMI ≥ 30 kg/m²) and non-obese (BMI ≤ 30 kg/m²) categories. Time to complete transvaginal ultrasound imaging was recorded in both patient populations and compared. Results: 216 patients met study criteria. Out of the 216, 89 (41%) were obese and 127 (59%) were non-obese. Average BMI of all participants was 29.2 ± 7.4 kg/m². Average time spent on ultrasound for patients with BMI <30 was 13:36 ± 01:28 and for BMI >30 15:34 ± 01:48 (p=0.46). There was no statistical difference between obese and non-obese patients and transvaginal scanning time > 10 minutes (OR 1.24, 95% CI 0.719-2.13, p=0.44) Discussion: Our results suggest that the time to obtain cervical length measurements via transvaginal ultrasounds is similar between obese and non-obese patients. Time necessary to perform endovaginal ultrasonography of the cervix does not appear to be affected by maternal BMI. Since length of time necessary to complete transvaginal cervical length measurement does not appear to be affected by maternal BMI, our results suggest that additional scheduling time does not need to be allocated for obese patients. Other investigators have shown that early incorporation of transvaginal assessment of fetal anatomy in obese women improved the rate of survey completion and demonstrated earlier completion of the fetal anatomic evaluation (Toscano et al, 2021). This study encourages the further use of transvaginal ultrasound in obese, obstetrical patients.

Comparison of trans-vaginal ultrasound cervical length measurement and Bishop score in predicting successful labour induction in term pregnancies at Ahmadu Bello University Teaching Hospital Zaria

The goal of induction of labour (IOL) is to achieve successful vaginal delivery and reduce caesarean section (CS). The gold standard method for assessing cervical status has been the use of the Bishop score (BS) which is not flawless leading to unnecessary intervention. Trans-vaginal ultrasound cervical length (CL) measurement has been compared with BS in predicting successful IOL. The objective of this study was to compare CL and BS in predicting successful IOL at Ahmadu Bello University Teaching Hospital. It was a cross sectional comparative study design conducted among pregnant women at 37-42 weeks of gestation slated for IOL between November 2017 to November 2018. Eighty-seven (87) women were recruited as participants. Each participant, had a trans-vaginal ultrasound (TVS) CL measured and each was followed by a digital cervical assessment using BS. Relevant data obtained was analysed using SPSS version 23. The significance level was considered at P< 0.05 IOL was successful in 66.2% (47) of the participants, while 15% (13) had CS. The receiver operating characteristic curve (ROC) demonstrated a better performance of the BS (AUC= 0.556, P= 0.433, CI= 0.426-0.673, PPV=52.8%) in predicting successful IOL than the TVS-CL measurement (AUC= 0.446, P=0.391, CI= 0.317-0.574) PPV=60.2%). Results further showed that the best cut off values for favourability for IOL for TVS-CL and BS were ≤2.5 cm and ≥5 respectively. The most important component of the BS predictive of successful IOL was cervical dilatation (OR= 0.603, P=0.011). TVS-CL did not demonstrate a diagnostic accuracy in predicting successful IOL in term pregnancies compared to BS.

Reduction in cervical length after vaginal progesterone in women with short cervix is significantly associated with preterm delivery at ≤ 34 weeks and < 37 weeks of gestation.

To evaluate the association between changes in cervical length (CL) after vaginal progesterone treatment and preterm delivery (PTD). This was a retrospective cohort study that included 197 singleton pregnancies without (n = 178) and with (n = 19) a history of PTD which were found to have a short cervix (≤ 25 mm) between 18 + 0 and 23 + 6 weeks' gestation with a follow-up transvaginal CL measurement taken at least 1 week after vaginal progesterone treatment started. Receiver-operating-characteristics (ROC)-curve analysis was performed and three CL shortening patterns were evaluated: (1) ≥ 10% reduction; (2) ≥ 20% reduction; and (3) ≥ 5 mm reduction relative to the first CL measurement. The predictive performance of each CL reduction cut-off and its association with PTD ≤ 34 weeks and PTD < 37 weeks were evaluated. Overall, the rate of PTD ≤ 34 weeks was 16.8% (33/197) and that of PTD < 37 weeks was 36.5% (72/197). The area under the ROC curve of cervical shortening expressed in % for predicting PTD ≤ 34 weeks and PTD < 37 weeks was 0.703 and 0.608, respectively. Cervical shortening was observed in 60/197 (30.5%) patients, with 49/60 (81.7%) women showing ≥ 10% reduction, 32/60 (53.3%) ≥ 20% reduction and 27/60 (45.0%) ≥ 5 mm reduction in CL. Sensitivity and specificity for PTD ≤ 34 weeks were, respectively, 48.5% and 79.9% for ≥ 10% reduction; 36.4% and 87.8% for ≥ 20% reduction; and 27.3% and 89.0% for ≥ 5 mm reduction in CL. For PTD < 37 weeks, sensitivity and specificity were, respectively, 36.1% and 81.6% for ≥ 10% reduction; 27.8% and 90.4% for ≥ 20% reduction; and 20.8% and 90.4% for ≥ 5 mm reduction in CL. The highest positive likelihood ratios for PTD ≤ 34 and < 37 weeks were for ≥ 20% CL reduction (2.98 (95% CI, 1.62-5.49) and 2.89 (95% CI, 1.52-5.57), respectively). Despite significant differences in sensitivity among the different cut-offs for cervical shortening, favoring the ≥ 10% reduction cut-off, a reduction of ≥ 20% in CL showed the strongest association with PTD ≤ 34 weeks (odds ratio (OR), 4.11 (95% CI, 1.75-9.62)) and < 37 weeks (OR,3.62 (95% CI, 1.65-7.96)), as compared with a less pronounced reduction in CL. In women with a short cervix treated with vaginal progesterone, a reduction in CL on a subsequent ultrasound scan can predict PTD ≤ 34 and < 37 weeks. A ≥ 20% reduction in CL had the highest positive likelihood ratio and strongest association with PTD ≤ 34 and < 37 weeks compared with ≥ 10% or ≥ 5 mm reduction. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Preterm Birth: Screening and Prediction.

Preterm birth (PTB) affects approximately 10% of births globally each year and is the most significant direct cause of neonatal death and of long-term disability worldwide. Early identification of women at high risk of PTB is important, given the availability of evidence-based, effective screening modalities, which facilitate decision-making on preventative strategies, particularly transvaginal sonographic cervical length (CL) measurement. There is growing evidence that combining CL with quantitative fetal fibronectin (qfFN) and maternal risk factors in the extensively peer-reviewed and validated QUanititative Innovation in Predicting Preterm birth (QUiPP) application can aid both the triage of patients who present as emergencies with symptoms of preterm labor and high-risk asymptomatic women attending PTB surveillance clinics. The QUiPP app risk of delivery thus supports shared decision-making with patients on the need for increased outpatient surveillance, in-patient treatment for preterm labor or simply reassurance for those unlikely to deliver preterm. Effective triage of patients at preterm gestations is an obstetric clinical priority as correctly timed administration of antenatal corticosteroids will maximise their neonatal benefits. This review explores the predictive capacity of existing predictive tests for PTB in both singleton and multiple pregnancies, including the QUiPP app v.2. and discusses promising new research areas, which aim to predict PTB through cervical stiffness and elastography measurements, metabolomics, extracellular vesicles and artificial intelligence.

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

IntroductionPreterm birth (PTB) is among the leading causes of perinatal and childhood morbidity and mortality. Therefore, accurate identification of pregnant women at high risk of PTB is key to enable...

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

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

Intra-Sonographer Correlation Between Transabdominal and Transvaginal Cervical Length Measurements and Associated Patient Demographics.

To assess transvaginal (TV) and transabdominal (TA) cervical length (CL) measurements' variability and patient factors associated with TA CL accuracy. We hypothesized that patient factors would affect the accuracy of TA CL. This was a prospective cohort study. During anatomy ultrasound, TA and TV CL measurements were obtained, distance from placental edge to internal cervical os assessed, and demographic questionnaires completed. Patients between 18 to 22 weeks and 6 days were included and those <18 year old or with a twin gestation were excluded. TA CL >0.5 cm different from TV length was considered inaccurate. A total of 530 patients were included. Exactly 18.7% had a prior cesarean, 9.8% a preterm birth, and 2.2% a cervical procedure. Mean age and BMI were 31.1 years and 27.8 kg/m2 . Median number of living children was one. Median TA and TV CL were 3.42 and 3.53 cm. Exactly 36% (95% CI: 32-40%) of TA CL measurements were inaccurate. CL of 3.4 cm corresponded to a mean difference of zero between TA and TV CL. TA ultrasound had a sensitivity of 25% and a specificity of 98.5% to detect TV CL <2.5 cm. On multivariable analyses, Hispanic ethnicity was associated with inaccurate TA measurement (OR 0.48, 95% CI: 0.24-0.96, P = .04). On average, TA CL underestimates TV CL when TV CL >3.40 cm and overestimates TV CL when TV CL <3.40 cm. Additional co-variates did not impact accuracy. TA ultrasound has low sensitivity to predict short cervix. Relying solely on TA CL to identify those who need intervention may miss diagnoses. It may be reasonable to develop protocols in which TV CL is used for TA CL <3.4 cm.

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.

The effectiveness of vaginal progesterone in reducing preterm birth in high-risk patients diagnosed with short cervical length after 24 weeks: A retrospective cohort study.

To assess the impact of progesterone treatment on maternal and neonatal outcomes in women with a history of preterm birth and short cervical length diagnosed after 24 weeks of gestation. A retrospective cohort study included women with a history of preterm birth and a transvaginal sonographic cervical length measurement of ≤ 25 mm, diagnosed between 24+0 and 33+6 weeks of gestation. Exclusion criteria included prior progesterone treatment, cervical cerclage, or pessary. The study population was divided into the progesterone treatment group and the non-treatment group. The study included 104 women, with 46.2% (48/104) receiving progesterone treatment and 53.8% (56/104) not receiving treatment. The rate of spontaneous preterm birth before 37 weeks of gestation was 43% (24/56) in the non-treatment group and 31% (15/48) in the progesterone treatment group (P = 0.14); the rate of spontaneous preterm birth before 34 weeks was 7% (4/56) in the non-treatment group and 0% (0/48) in the progesterone treatment group (P = 0.05). Progesterone treatment was associated with a significant decrease in neonatal intensive care unit admissions (OR 0.20, 95% CI 0.05-0.74) and in the neonatal hospitalization period (mean difference in days 2.43, 95% CI 0.44-4.42). The risk of recurrent spontaneous preterm birth was highest (71%) among women with two or more previous preterm deliveries who did not receive progesterone treatment, and lowest (24%) among women with one previous preterm delivery who received progesterone treatment. Progesterone treatment was associated with a reduction in rates of spontaneous preterm birth before 34 weeks of gestation, neonatal intensive care unit admission, and neonatal length of stay in high-risk patients, even when initiated after 24 weeks of gestation.

Cervical Length Measurement at Term Pregnancy as a Predictor of Time of Onset of Labour and Mode of Delivery: A Longitudinal Study

Introduction: Cervical assessment has moved from digital examination to sonographic evaluation in recent years. Predicting the time of onset of labour and mode of delivery at term is a great concern for both the pregnant woman and her relatives. Aim: To predict the time of onset of labour and mode of delivery by Transvaginal sonographic measurement of cervical length at term. Materials and Methods: This longitudinal study was conducted in the Department of Obstetrics and Gynaecology, SRM Medical College Hospital and Research Centre, Kattankalathur, Tamil Nadu, India, from March 2021 to August 2021. All low-risk singleton pregnancies between 38-40 weeks of gestation were included. Cervical length (in mm) was measured transvaginally by the principal investigator between 38 and 40 weeks. When the labour sets in the duration between cervical length measurement and the onset of labour, duration of labour and mode of delivery were noted. Pearson correlation coefficient was used to quantify the association between cervical length and time of onset of labour and duration of labour. Results: In the study, 164 low-risk patients (143 Primigravida patients+21 Multigravida patients) between 38-40 weeks were included. In patients with spontaneous onset of labour, 45 (70.3%) had labour onset within 120 hours (5 days) when cervical length was ≤30 mm, when compared with 7 (22.58%) when cervical length was &gt;30 mm (p=0.001). In patients with cervical length ≤30 mm, vaginal delivery occurred in 47 (73.43%) (p=0.019). In women with induced labour with cervical length ≤30 mm, 13 (61.9%) had labour onset within 120 hours when compared to 15 (30.6%) in women with cervical length &gt;30 mm (p=0.02). Vaginal delivery occurred in 5 (29.41%) of women when cervical length was ≤30 mm compared to 32 (65.30) in women when cervical length &gt;30 mm which may be attributed to other causes. There was a significant positive correlation between cervical length and time of onset of labour (Correlation coefficient=0.221, p-value=0.004). There was a negative correlation between cervical length and duration of labour which was not statistically significant (Correlation coefficient=-0.108, p=0.25). There was no significant difference in mean cervical length measurement between vaginal delivery and caesarean section. Conclusion: Transvaginal cervical length measurement at term positively correlates with time of onset of labour but not with duration of labour and mode of delivery

Screening vs. no screening for preterm delivery in low-risk singleton pregnancies: comparison by propensity score analysis

PurposeTo compare the effect of a policy of screening for spontaneous preterm delivery (SPD) by transvaginal cervical length (CL) measurement versus a no screening policy in the prevention of severe prematurity.MethodsRetrospective study on low-risk singleton pregnancies examined at 20–24 weeks. Two cohorts, one with SPD screening and the other without screening, were matched using propensity analysis to create the study groups. Women with short CL were treated with vaginal progesterone and/or cervical cerclage/pessary. The outcomes examined were SPD < 32 weeks (SPD 32) and SPD between 20 and 32 weeks (SPD 20–32).ResultsScreening for SPD was associated with a significant reduction in the rate of SPD at less than 32 weeks (0.3 vs. 0.8%, p = 0.001 in the screened and no screened pregnancies, respectively) and in the rate of SPD 20–32 (0.3 vs. 0.9%, p = 0.005 in the screened and no screened pregnancies, respectively). After adjusting for maternal age, parity, body mass index, smoking and mode of conception, the screening group had significantly lower hazard for SPD 20–32 (HR = 0.36, 95% CI: 0.18–0.75, p = 0.006) and SPD32 (HR = 0.39, 95% CI: 0.19–0.82, p = 0.013).ConclusionScreening for SPD by transvaginal CL measurement in mid-pregnancy may reduce the incidence of severe prematurity in low-risk singleton pregnancies.

Fetal Fibronectin and Cervical Length as Predictors of Spontaneous Onset of Labour and Delivery in Term Pregnancies.

(1) Objective: This study aimed to determine whether qualitative fetal fibronectin and transvaginal sonographic measurement of cervical length are effective in predicting delivery in term pregnancies within 5 days of the test. (2) Methods: We examined 268 women with singleton pregnancies presenting themselves at 37+0–40+4 weeks (median 38 weeks + 1 day) of gestation with irregular and painful uterine contractions, intact membranes and cervical dilatation less than 2 cm. All women were admitted to hospital up to 72 h after birth. On admission, a qualitative fetal fibronectin test was performed in cervicovaginal secretions and transvaginal sonographic measurement of cervical length was carried out. The primary outcome measure was delivery within 5 days of presentation. RESULTS: Among the women who delivered within 5 days after admission, 65.2% had positive fFN assessment, 43.5% had cervical length below 26 mm, 52.2% had the age > 32.5 years, 34.8% were nulliparous and 56.5% had gestational age ≥ 275 days. Logistic regression analysis demonstrated that significant contributors to the prediction of delivery within 5 days were fibronectin positivity, cervical length ≤ 26 mm, maternal age > 32.5 years and gestational age ≥ 275 days, with no significant contribution from parity. (3) Conclusions: Qualitative fetal fibronectin test and transvaginal cervical length measurement in term pregnancies are useful tests for predicting spontaneous onset of labour within 5 days. It helps women and healthcare providers to determine the optimum time for hospital admission.

Comparison of transvaginal sonographic cervical length measurement and Bishop score for predicting labour induction outcomes.

Induction of labour (IOL) is of increasing prevalence worldwide and reliable prediction of its successful outcome is important. Traditional clinical methods for predicting successful IOL outcomes have been supplemented with newer technologies. The aim of this study was to compare transvaginal sonographic (TVS) cervical length measurement with Bishop score in predicting labour induction outcomes. This study included pregnant women with term pregnancy, indication for IOL and unfavourable cervix (Bishop score >6) who had TVS performed prior to IOL. Exclusion critetia were regular contractions, ruptured membranes, non-cephalic presentation, uterine scar and pregnancy complications potentially influencing study outcomes. Outcomes measured were successful IOL defined as achievement of active phase of labour and vaginal delivery. Receiver operating characteristic (ROC) curves were used to determine diagnostic accuracy and sensitivity, specificity, positive and negative predictive values. Statistical significance was defined as p<0.05. Among 112 studied participants, IOL was successful in 101 (90.2%) pregnant women. AUC for Bishop score >2 was 0.831 (95% CI, 0.744-0.917, p<0.001) and for cervical length <30mm 0.679 (95% CI 0.514-0.844, p<0.052). A total of 81 (72.3%) pregnant women delivered vaginally; AUC for Bishop score >2 was 0.754 (95% CI 0.648-0.861, p<0.001) and for cervical length <30mm 0.602 (95% CI 0.484-0.720, p=0.092) which was the only insignificant predictor. Bishop score >2 is a better predictor for both successful IOL and vaginal delivery among induced women with term pregnancy and unfavourable cervix compared to cervical length <30mm.

Prediction of preterm delivery in threatened preterm labour with short cervical length

In this study, we evaluated the value of the uterocervical angle (UCA), myometrial thickness (MT), sICAM-1, sVCAM-1, soluble E-selectin (sE-selectin) and pentraxin 3 (PTX3) levels in women with threatened preterm labour (TPL) in predicting spontaneous preterm birth (sPTB) within 14 days in symptomatic women with cervical length (CL) measurements between 10 and 25 mm. Forty-six patients diagnosed with TPL, 47 healthy pregnant women were evaluated in a case-control study. sE-selectin (AUC = 0.744, p = .007) and PTX3 (AUC = 0.711, p = .019) were found to be effective in predicting preterm delivery within 14 days. In conclusion, maternal sE-selectin and PTX3 levels may be helpful in identifying pregnancies that will deliver within 14 days in symptomatic women with CL measurements between 10 and 25 mm. However, maternal sICAM-1 and sVCAM-1 levels, MT and UCA are not effective in the prediction of sPTB in TPL pregnancies. Impact Statement What is already known on this subject? Aetiology of spontaneous preterm birth (sPTB) is unclear and believed to be multifactorial, infection, inflammation, vascular endothelial dysfunction and uteroplacental ischaemia are all considered to be related to preterm delivery syndrome. Transvaginal cervical length (CL) measurement is a good indicator of increased risk of sPTB. Inflammation is accepted to have a central role in the process of labour. What do the results of this study add? soluble E-selectin (sE-selectin) and pentraxin 3 (PTX3) levels may be helpful in identifying pregnancies that will deliver within 14 days in symptomatic women with CL measurements between 10 and 25 mm. What are the implications of these findings for clinical practice and/or further research? This study will help understand the important role of the inflammatory process in predicting spontaneous preterm birth.

Normative Values of Mid Trimester Cervical Consistency Index in Women Delivering at Term

Abstract Aims and Objective Cervical Consistency Index (CCI) is a new technique to measure the consistency of Cervix (softening) and is expected to show changes before cervical shortening. The aim of this study was 1. To find out the normative values of mid-trimester Cervical Consistency Index in women delivering at term. 2. To compare the discriminative ability of cervical consistency index with cervical length for prediction of spontaneous preterm birth. Method A total of 144 antenatal patients undergoing mid-trimester anomaly scan were subjected to transvaginal cervical length measurement as per Fetal Medicine Foundation criteria. Cervical consistency index was measured as defined by Para et al. The anterior–posterior diameter of cervix was measured before compression (AP) and after compression (AP') in the same sitting. Cervical consistency index (CCI) was calculated by the formula:CCI = APⅹ/AP × 100;The result of CCI was not used in the clinical management of the patient. Women who delivered at 37 weeks and beyond were included to form the normative data. An attempt was made to study the ability of mid-trimester cervical consistency index to predict spontaneous preterm birth as compared to cervical length (CL). Results Range of CCI in our study was 41–100% and that of CL was 2–4 cm.Based on values of CCI and CL an ROC curve was made, AUC measured for CCI was 0.923 and for CL was 0.849. The cut off determined for CCI was 64.5%, above which all women delivered at ≥ 37 weeks. Only Two women who delivered preterm (&lt; 37) weeks had a CCI of less than 64.5% (64 and 47%), but cervical length was greater than 2.5 cms in both of them. The Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value and accuracy of CCI for predicting term delivery at a cutoff of 64.5% in our study was 83.8%, 100%, 100%, 8% and 93.8% respectively, whereas the corresponding figures for predicting preterm delivery were 100%, 83.8%, 8%, 100% and 93.8%. Discriminative ability of CCI in comparison to CL could not be determined because only two women delivered preterm in our study. Conclusion This was a pilot study to form the normative values of CCI for women delivering at term. At a cutoff value of 64.5% or more all women delivered at term. Two women who delivered preterm had a CCI of less than 64.5%. Further large studies are required before CCI can be incorporated as a routine to assess the antenatal cervix.

Prediction of labour onset in women who present with symptoms of preterm labour using cervical length

BackgroundDiagnosis of preterm labour is difficult because initial symptoms and signs are often mild and may occur in continuing pregnancies. This study aims to investigate the utility of measuring cervical length, using transvaginal ultrasound, in women presenting to the delivery suite with symptoms of preterm labour.MethodsThis was a prospective cohort study performed in KK Women’s and Children’s Hospital, Singapore from September 2017 to July 2018. Women with singleton pregnancies, presenting with symptoms of contraction pain, between 24+ 0 to 36+ 6 weeks gestation, were included. Transvaginal ultrasound cervical length measurements were done at presentation to the labour ward, after four hours and in the following morning. The primary outcome of the study was delivery within 1 week. All statistical analyses were conducted with Microsoft Excel and Statistical Package for the Social Sciences.ResultsA total of 95 subjects were included. A one-millimeter increase in the 1st cervical length increases scan-to-delivery time by 0.802 days (p-value 0.003, CI 0.280–1.323). Receiver Operator Characteristic (ROC) curve analysis for prediction of delivery within 1 week showed an Area Under Curve (AUC) of 0.667, optimal cut-off value of 27.5mm (sensitivity 77.8 %, specificity 61.6 %). A one-millimetre increase in the 3rd cervical length increases scan-to-delivery time by 0.770 days (p-value 0.023, CI 0.108–1.432). ROC curve analysis for prediction of delivery within 1 week showed an AUC of 0.915, optimal cut-off value of 25.5mm (sensitivity 100 %, specificity 73.6 %). However, the change in cervical length over a period of 1 day was not significant in predicting delivery within 1 week.ConclusionsOur results indicate that by using a cervical length cut off of 27.5mm at presentation, we would have predicted 77.8 % of deliveries within 1 week. If we were to repeat the cervical length scan the next day, with the same cut-off of 27.5mm, we would have predicted 100 % of deliveries within 1 week. In our study, measuring the transvaginal ultrasound cervical length is a reliable diagnostic test for delivery within 1 week. However, the results are limited by the small sample size. Further studies should be conducted with a larger sample size.

Utility of follow-up cervical length screening in low-risk women with a cervical length of 26 to 29 mm

In women with a previous preterm birth, a protocol for serial cervical length screening has been studied and recommended for the identification and treatment of a short cervix. Cervical length screening along with vaginal progesterone has been suggested for low-risk women with singleton pregnancies to treat a short cervix and reduce preterm birth. However, specific protocols for single vs serial ultrasound measuring cervical length in this population are not established. Cost-effectiveness of universal cervical length screening depends on the cost of screening; follow-up of borderline measurements can contribute to increased costs with uncertain benefit. This study aimed to determine the utility of follow-up cervical length screening in otherwise low-risk women with singleton pregnancies with a midtrimester cervical length measurement of 26 to 29 mm through the assessment of the rate of short cervix (≤25 mm) on follow-up ultrasound and subsequent delivery outcomes. This was a 2-year retrospective cohort study at a single urban institution of women with singleton pregnancies with no previous spontaneous preterm birth and an initial transvaginal ultrasound cervical length measurement of 26 to 29 mm identified during universal cervical length screening at time of anatomy ultrasound (18 0/7 to 22 6/7 weeks' gestation). The primary outcome was the rate of short cervix (defined as ≤25 mm on transvaginal ultrasound) on follow-up ultrasound at <24 weeks' gestation. Secondary outcomes included the rate of spontaneous preterm birth (<37 and <34 weeks' gestation). During the study period, there were 2801 women with singleton pregnancies at 18 0/7 to 22 6/7 weeks' gestation with transvaginal ultrasound cervical length screening at time of anatomy scan. Among those women, 201 had a cervical length of 26 of 29 mm, and 184 (7%) had no previous spontaneous preterm birth and were included in the study. Furthermore, 144 women (78%) had a follow-up cervical length completed before 24 weeks' gestation. The mean follow-up interval was 1.5±0.6 weeks. Overall, the percentage of short cervix (≤25 mm) on follow-up was 15% (n=21). Baseline characteristics were similar, but the initial cervical length measurement was shorter in women who subsequently developed a short cervix (26.7±0.8 vs 27.8±1.0; P<.01). Delivery outcomes were available for 126 patients. The rate of spontaneous preterm birth at <37 weeks' gestation in women with an initial cervical length 26 to 29 mm and subsequent short cervix was significantly higher than the rate of spontaneous preterm birth in a historical cohort of low risk women with an initial cervical length >25 mm (16% vs 3%; P=.03). The rate of spontaneous preterm birth at <34 weeks' gestation in women with a subsequent short cervix was 11% (2 of 19). Here, approximately 15% of low-risk women with singleton pregnancies with a midtrimester cervical length measurement of 26 to 29 mm will experience cervical shortening of ≤25 mm before 24 weeks' gestation. Compared to women with singleton pregnancies without a history of preterm birth, the rate of spontaneous preterm birth (16%) in women with an initial cervical length of 26 to 29 mm and a subsequent cervical shortening of ≤25 mm is significantly higher. A total of 111 follow-up ultrasounds measuring cervical length would be required to prevent 1 early preterm birth at <34 weeks' gestation.

581 Achieving maternal weight gain recommendations and its impact on cervical length shortening in twin gestations

To determine if underachievement of recommended maternal weight gain in twin gestations is associated with a shortened mid-trimester transvaginal cervical length (TVCL). Retrospective cohort study of twin gestations receiving TVCL surveillance between 2003 and 2010. Each woman was categorized as having achieved vs underachieved recommended maternal weight gain at delivery using institutional BMI and gestational age- specific weight gain guidelines for women carrying twins. TVCL measurements were routinely obtained between 18-24 weeks’ gestation and the shortest of three measurements acquired were compared between groups. Poisson regression was used to calculate adjusted relative risks (aRR) and 95% confidence interval (CI) of TVCL<15mm controlling for maternal race, cerclage, prior preterm birth, and pre-pregnancy BMI. 304 patients met inclusion criteria with 160 (52.6%) achieving and 144 (47.4) underachieving recommended weight gain guidelines during their study pregnancy. Women who underachieved had significantly shorter median TVCL (37 vs 40mm; p=.003; Figure 1). There were higher rates of TVCL <30mm (26.4% vs 17.5%; p=.061), <25mm (16.0% vs 11.3%; p=.229), and <20mm (11.8% vs 6.3%; p=.09), but these did not reach statistical significance in either the adjusted or unadjusted analysis. However, underachieving weight gain remained significantly associated with a shortened TVCL <15mm (9% vs 2.5%; aRR 3.2, CI 1.2-8.6) after adjusting for confounders. Underachievement of recommended maternal weight gain was also significantly associated with preterm birth <34 weeks’ gestation (58.7% vs 33.3%; p<0.001). Inadequate maternal weight gain in twin gestations independently contributes to a shortened mid-trimester cervical length which is strongly associated with prematurity. The mechanism is currently unknown; however, poor maternal nutrition may be a modifiable risk factor influencing pathologic premature cervical change.