Cervical Length Measurement Research Articles

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.

Centile charts of cervical length in singleton and twin pregnancies between 16 and 24 weeks of gestation

The aim of this study was to determine the standard mid-trimester cervical lengths of singleton and twin pregnancies. This study was conducted by retrospective analysis of mid-trimester transvaginal cervical measurements of women with singleton and twin pregnancies that were examined by a single perinatologist in a single center. A total of 4621 consecutive asymptomatic pregnant women admitting for advanced obstetric ultrasound screening were evaluated. Of these 4340 (93.9%) were second trimester singleton pregnancies and 281 (6.1%) were twin pregnancies and were included. Mean cervical length measurements of singleton and twin pregnancies were 38.2±6.5 mm and 37.6±7.2 mm respectively (p=0.17). Overall, the 5th percentile of cervical length measurement after analysing singleton and twin pregnancies together was 29.4 mm at 16 weeks, 30 mm at 17 weeks, 30 mm at 18 weeks, 30 mm at 19 weeks, 30 mm at 20 weeks, 30 mm at 21 weeks, 30 mm at 22 weeks, 31 mm at 23 weeks, 29 mm at 24 weeks. In our population the 5th precentile value of cervical length which is 30 mm in singletons and 10th percentile cervical length which is 31 mm in twins can be used to follow-up and treat pregnant women at risk for preterm delivers.

How endocervicoscopy can impact obstetric outcomes in women undergoing LEEP for CIN2 + : a retrospective cohort analysis.

To assess the impact of preoperative endocervicoscopy on obstetric outcomes and complications in women undergoing LEEP for CIN2 + . This was a retrospective cohort study carried out between October 2012 and April 2018. All women had undergone cervical length measurement at T0 (before LEEP), T1 (6months after LEEP), and T2 (at 20weeks of pregnancy) through transvaginal ultrasound examination after LEEP for CIN2 + . A total of 528 patients fulfilled our inclusion criteria and contributed to the final analysis: 288 had undergone endocervicoscopy before the excisional procedure (Group A), while the remaining 240 (Group B) did not. Patients who did not undergo endocervicoscopy showed a greater amount of tissue excised at LEEP compared to those of Group A (6.7% vs 31.9% in Group A and B, p < 0.01, respectively). A statistically relevant difference was detected in the lesion margins involvement: negative in 93.8% in Group A compared to 65.6% in Group B. The cervicometry before the treatment resulted in similar between the two groups, while a statistically significant difference was noted after 6months (37.5 ± 2.9mm in Group A vs 35.1 ± 3.8mm in Group B, p < 0.01) and at 20th week pregnancy (36.9 ± 5.3mm in Group A vs 33.5 ± 5.6mm in Group B, p < 0.01). The number of pregnancies after LEEP as well as the difference in the elapsed time (in months) did not result in a statistical significance between the two groups. The threatened preterm labor (TPL) and the threatened miscarriage showed a statistically significant difference in incidence between the two groups (4,2% and 4.2% in Group A vs 15.3% and 25% in Group B, p < 0.01, respectively). Endocervicoscopy reduces the size of the LEEP sample and in particular its depth, saving healthy cervical tissue, and guarantees the total eradication of the lesion as the resection margins are negative in almost all cases, allowing for a reduction of the rate of TPL and threatened miscarriage in women with CIN2 + , especially with Type 2 or 3 cervical squamocolumnar junction (SCJ).

Identification of biochemical biomarkers associated with premature cervical shortening in high-risk, asymptomatic pregnant women: a retrospective data analysis

Reliably predicting spontaneous preterm birth remains challenging, therefore it persists as a major contributor to perinatal morbidity and mortality. The use of biomarkers to predict premature cervical shortening, a recognised risk factor for spontaneous preterm birth, is yet to be fully explored in current literature. This study evaluates seven cervicovaginal biochemical biomarkers as possible predictors of premature cervical shortening. Asymptomatic, high-risk women (n = 131) presenting to a specialised preterm birth prevention clinic were analysed through a retrospective data analysis. Cervicovaginal biochemical biomarker concentrations were obtained, and the shortest cervical length measurement, up to 28 weeks’ gestation, was recorded. Associations between biomarker concentration and cervical length were then analysed. Of the seven biochemical biomarkers, Interleukin-1 Receptor Antagonist and Extracellular Matrix Protein-1 had statistically significant relationships with cervical shortening below 25 mm. Further investigation is required to validate these findings and any downstream clinical utility, with intentions to improve perinatal outcomes. IMPACT STATEMENT What is already known on this subject? Preterm birth is a major cause of perinatal morbidity and mortality. A woman’s risk of delivering preterm is currently stratified using historical risk factors, mid-gestation cervical length, and biochemical biomarkers such as foetal fibronectin. What do the results of this study add? In a cohort of high-risk, asymptomatic pregnant women, two cervicovaginal biochemical biomarkers, Interleukin-1 Receptor Antagonist and Extracellular Matrix Protein-1, displayed associations with premature cervical shortening. What are the implications of these findings for clinical practice and/or further research? Further investigation into the possible clinical utility of these biochemical biomarkers is warranted, with a view to improving preterm birth prediction and antenatal resource utilisation, thereby reducing the burden of preterm birth and its sequelae in a cost-effective manner.

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.

Prediction of preterm labour by measurement of cervical length in first trimester (11 to 13+6 weeks) and second trimester (20 to 24 weeks) by using TVS

Prediction of preterm labour by measurement of cervical length in first trimester (11 to 13+6 weeks) and second trimester (20 to 24 weeks) by using TVS

Cervical Length Surveillance in Patients With a History of Early Versus Late Preterm Birth [ID: 1378074

INTRODUCTION: The American College of Obstetricians and Gynecologists recommends patients with a history of a preterm birth (PTB) be monitored with serial cervical length (CL) measurements for short cervix. We sought to evaluate the utility of serial CL surveillance in patients based on gestational age at the time of their prior PTB. METHODS: This was a multi-institutional retrospective study of pregnant patients with a history of spontaneous PTB between 23 weeks 0 days and 36 weeks 6 days that underwent a transvaginal CL between January 2017 and December 2021. Multiple gestation pregnancies were excluded. Data were compared between patients with a history of late PTB (&gt;34 weeks) and patients with a history of early PTB (&lt;34 weeks) using χ2 tests, t tests, and ANOVA analyses, as appropriate (α=0.05). Institutional review board approval was obtained for the study. RESULTS: Of 321 patients with a history of spontaneous PTB, 106 (33%) had a late PTB and 215 (67%) had an early PTB. Patients with a prior late PTB were less likely to be on 17-OHP (42.5% versus 54.5%, P=.04) and have a cerclage placed (4% versus 19.5%, P=.0002) compared to patients with an early PTB. Patients with a prior late PTB had their first CL performed at later gestations (18 weeks 0 days versus 17 weeks 2 days, P=.016) and fewer CL measurements (3.2 versus 3.5, P=.034). There was no difference in the gestational age that the shortest CL was detected (21 weeks 0 days versus 21 weeks 0 days, P=.98). CONCLUSION: In patients with either a history of early or late spontaneous PTB, universal CL surveillance at the time of the anatomy (18–20 weeks) may be sufficient to identify patients for intervention.

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

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

Change in prevalence of preterm birth in Israel following publication of national guidelines recommending routine sonographic cervical-length measurement at 19-25 weeks' gestation.

To compare the prevalence of preterm birth (PTB) (delivery before 37 weeks) in Israel before and after publication of national guidelines recommending second-trimester sonographic cervical-length (CL) measurement. The Israeli Society of Obstetrics and Gynecology (ISOG) guidelines, issued on 1 January 2012, specified that CL should be measured transabdominally or, if this is not possible, transvaginally, at the 19-25-week ultrasound anomaly scan and that CL < 25 mm should indicate further work-up and treatment, although the type of treatment was unspecified. In 2000, the Israel Ministry of Health issued a legal requirement for the submission of delivery records to a national registry. These data were used to compare PTB prevalence in the period before (2000-2011) and that after (2012-2020) publication of the guidelines, as well as trends within each time period. Information was available on singleton and multiple pregnancy and maternal age and parity, as well as low birth weight (< 2500 g). During the period 2000-2020, there were 3 403 976 infants liveborn in Israel: 1 797 657 before and 1 606 319 after publication of the ISOG guidelines. There were 247 187 PTBs overall, with a prevalence of 7.64% (95% CI, 7.52-7.77%) before publication of the guidelines and 6.84% (95% CI, 6.43-7.24%) afterwards (P < 0.0002, two-tailed). The annual PTB prevalence was static in the first time period but declined by 0.18% per annum during the second period, after publication of the guidelines. The proportionate reduction in PTB prevalence after compared with before publication of the guidelines was 10% overall, 9% for PTB at 33-36 weeks, 18% for PTB at 28-32 weeks and 24% for PTB at < 28 weeks. After publication of the guidelines, reduced prevalence of PTB was observed among singletons (5.49% before vs 4.83% after, P < 0.0001), but not among infants in twin or higher-order multiple pregnancy. There was a statistically significant reduction in the rate of PTB following publication of the guidelines in both nulliparous and parous women and in the 19-39-year-old maternal-age group. Although reductions in PTB prevalence were also noted in high-risk age groups (maternal age < 19 years and ≥ 40 years), these did not reach statistical significance. Following publication of the guidelines, there was a statistically significant reduction in the prevalence of birth weight under 2500 g, of a magnitude similar to that for PTB prevalence. The publication of national guidelines recommending routine CL measurement at the time of the second-trimester anomaly scan was associated with a fall in PTB prevalence in singleton pregnancies. Whilst direct evidence linking screening with this fall in prevalence is lacking, it is likely that implementation of routine CL screening played an important role in the reduction of PTB rate. Our experience indicates that screening can be incorporated into the second-trimester anomaly scan. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Short cervix and preterm birth in the top end.

Reducing rates of preterm birth (PTB) remains a significant challenge. The Northern Territory (NT) records some of the highest rates of PTB in the country, especially in First Nations women. In 2014, a Western Australian (WA) preterm birth prevention initiative involved the implementation of seven key initiatives. One of these was routine mid-trimester cervical length measurement. The initiative successfully reduced PTB rates following its first year of implementation. This was the first successful reduction in PTB, including the earlier gestational ages, across a population. To assess the uptake of routine cervical length measurement in the Top End of the NT after the success of the WA PTB prevention initiative and assess if treatment of a short cervix improved PTB rates. A retrospective cohort study of all women who received antenatal care and delivered their baby at the NT's only tertiary hospital was performed. Mid-trimester ultrasound scan data were collected from two separate time windows, before and after the implementation of the WA intervention. Treatments and gestational age at birth were recorded. Adoption of routine screening of cervical length measurement at mid-trimester ultrasound in the NT was successful, increasing from 4 to 88%. Detection rates of short cervix doubled. However, there was no difference to PTB rates despite targeted management. PTB remains a significant challenge in the NT, especially for First Nations women who are found to have a short cervix more commonly than non-Indigenous women in the Top End.

Use of pessary for cervical insufficiency: a discussion

Annually, about 15 million of infants are born prematurely, and preterm birth is associated with an increased risk of neonatal morbidity and mortality. Further, the risk of repeated premature birth is relatively high, as 25% of pregnancies following those interrupted at 23-28 weeks of gestation also result in a preterm birth within the similar time frame. Among the major risk factors of preterm birth is cervical insufficiency, and cervical length measurement is recommended for all pregnant women at 18−21 weeks of gestation. For patients at high risk of late miscarriage and preterm birth, cervical length measurement should be performed weekly from 15 to 24 weeks of gestation. The use of pessary, which reduces amniotic sac pressure on the internal os, has been suggested as an appropriate option to correct cervical insufficiency as it does not require surgery, has low risk of complications and is easy to use. Relevant papers published hitherto report contradictory results, which require further research.

The Use of Mid-Pregnancy Cervical Length to Predict Preterm Birth in Brazilian Asymptomatic Twin Gestations.

To describe a reference curve for cervical length (CL) in mid-trimester twin gestations using transvaginal ultrasound (TVU) and to investigate whether short CL increases spontaneous preterm birth (sPTB) in asymptomatic twin pregnancies. This was a prospective cohort study performed at 17 outpatient antenatal facilities of Brazil with women at 18 0/7 to 22 6/7 weeks of gestation who participated in a randomized clinical trial screening phase (P5 trial) between July 2015 and March 2019. TVU was performed to provide CL measurement in all screened women. Almost all women with CL ≤ 30 mm received vaginal progesterone 200mg/day and they were also randomized to receive cervical pessary or not. We considered data from the CL distribution among asymptomatic twin pregnancies and analyzed CL and its association with PTB generating receiver operating characteristics (ROC) curves and Kaplan-Meier curves. A total of 253 pregnant women with twins were included in the distribution curve. The mean CL was 33.7 mm and median was 35.5mm. The 10th percentile was 17.8mm. We identified a PTB rate of 73.9% (187/253) with 33.6% of sPTB < 37 (85/253) and 15% (38/253) of sPTB < 34 weeks. The best cutoff point to predict sPTB < 37 was 24.15 mm. However, the ROC curve showed a poor performance (0.64). The Kaplan-Meier survival curves identified that only CL values ≤ 20mm were associated to sPTB < 34 weeks. A cutoff point of CL ≤ 20 mm can be interesting point to identify short cervix in Brazilian twin pregnancies. However, in Brazilian asymptomatic twin pregnancies, CL does not show a good performance to predict PTB.

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.

First-trimester prediction of preterm prelabour rupture of membranes incorporating cervical length measurement

ObjectivesTo examine early pregnancy risk factors for preterm prelabour rupture of membranes (PPROM) and develop a predictive model. Study designRetrospective analysis of a cohort of mixed-risk singleton pregnancies screened in the first and second trimesters in three Danish tertiary fetal medicine centres, including a cervical length measurement at 11–14 weeks, at 19–21 weeks and at 23–24 weeks of gestation. Univariable and multivariable logistic regression analyses were employed to identify predictive maternal characteristics, biochemical and sonographic factors. Receiver operating characteristic (ROC) curve analysis was used to determine predictors for the most accurate model. ResultsOf 3477 screened women, 77 (2.2%) had PPROM. Maternal factors predictive of PPROM in univariable analysis were nulliparity (OR 2.0 (95% CI 1.2–3.3)), PAPP-A < 0.5 MoM (OR 2.6 (1.1–6.2)), previous preterm birth (OR 4.2 (1.9–8.9)), previous cervical conization (OR 3.6 (2.0–6.4)) and cervical length ≤ 25 mm on transvaginal imaging (first-trimester OR 15.9 (4.3–59.3)). These factors all remained statistically significant in a multivariable adjusted model with an AUC of 0.72 in the most discriminatory first-trimester model. The detection rate using this model would be approximately 30% at a false-positive rate of 10%. Potential predictors such as bleeding in early pregnancy and pre-existing diabetes mellitus affected very few cases and could not be formally assessed. ConclusionsSeveral maternal characteristics, placental biochemical and sonographic features are predictive of PPROM with moderate discrimination. Larger numbers are required to validate this algorithm and additional biomarkers, not currently used for first-trimester screening, may improve model performance.

Propess versus prostin for induction of labour in term primiparous women

The rate of induction of labour has increased over the decades and numerous medications are available in the market. This study compares the efficacy and safety between dinoprostone slow-release pessary (Propess) and dinoprostone tablet (Prostin) for labour induction at term in nulliparous women. This was a prospective single-blind randomized controlled trial conducted in a tertiary medical centre in Taiwan from September 1, 2020 to February 28, 2021. We recruited nulliparous women at term with a singleton pregnancy, fetus in cephalic presentation, an unfavourable cervix, and the cervical length had been measured by transvaginal sonography three times during labour induction. The main outcomes are duration from induction of labour to vaginal delivery, vaginal delivery rate, maternal and neonatal complication rates. In both groups, Prostin and Propess, 30 pregnant women were enrolled. The Propess group had higher vaginal delivery rate but it did not meet statistically significant difference. The Prostin group had significantly higher rate of adding oxytocin for augmentation (p=0.0002). No significant difference was observed in either labouring course, maternal or neonatal outcomes. The probability of vaginal delivery was independently related to the cervical length measured by transvaginal sonography 8h after Prostin or Propess administration as well as neonatal birth weight. Both Prostin and Propess can be used as cervical ripening agents with similar efficacy and without significant morbidity. Propess administration was associated with higher vaginal delivery rate and less need to add oxytocin. Intrapartum measurement of cervical length is helpful in predicting successful vaginal delivery.

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.

The Association between Cervical Length and Successful Labor Induction: A Retrospective Cohort Study.

This study aimed to determine whether transvaginal sonographic measurement of cervical length before labor induction can predict successful induction. This retrospective study recruited 138 pregnant women who underwent labor induction at 37-41 weeks of gestation. Cervical length was measured using transvaginal ultrasonography before labor induction. Labor was induced according to the hospital protocol. Age, gestational age (GA), parity, body mass index (BMI), Bishop score, hemoglobin level, maternal disease, and epidural anesthesia were also recorded. Labor induction outcomes, including cesarean section for failed induction, time of induction, and the three labor stages, were assessed. From December 2018 to December 2021, 138 women were recruited for our study, including 120 and 18 women with successful and failed labor induction, respectively. Shorter cervical length (≤3.415 cm, OR = 6.22, 95% CI = 1.75-22.15) and multiparity (OR = 17.69, 95% CI = 2.94-106.51) were associated with successful induction. Higher BMI was associated with failed induction (OR = 0.87, 95% CI = 0.75-0.99). Age, GA, Bishop score, and fetal birth weight were not associated with successful labor induction. The ROC curve showed a cervical length cutoff value of 3.415 cm, revealing 76.8% of the area under the curve. In conclusion, a shorter cervical length (≤3.415 cm) was associated with a higher chance of successful labor induction (76.8%). This parameter might be used to predict the chance of successful labor induction. This information could help better inform clinician discussions with pregnant women concerning the chance of successful labor induction and consequent decision-making. Nevertheless, further large-scale clinical trials are warranted.

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

A randomized clinical trial of Premaquick biomarkers versus transvaginal cervical length for pre-induction cervical assessment at term among pregnant women.

To compare Premaquick biomarkers (combined insulin-like growth-factor binding protein 1 and interleukin-6) and cervical length measurement via transvaginal ultrasound for pre-induction cervical evaluation at term among pregnant women. A randomized clinical trial of consenting pregnant women at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria. The women were randomized equally into Premaquick group (n = 36) and transvaginal ultrasound group (n = 36). The cervix was adjudged 'ripe' if the Premaquick test was positive or if the trans-vaginal measured cervical length was less than 28 mm. The primary outcome measures were the proportions of women who needed prostaglandin analogue for cervical ripening and the proportion that achieved vaginal delivery after induction of labour. The trial was registered in Pan African clinical trial registry (PACTR) registry with approval number PACTR202001579275333. The baseline characteristics were similar between the two groups (p > 0.05). There was no statistically significant difference between the two groups in terms of proportion of women that required prostaglandins for pre-induction cervical ripening (41.7 versus 47.2%, p = 0.427), vaginal delivery (77.8 versus 80.6%, p = 0.783), mean induction to delivery interval (22.9 ± 2.81 h versus 24.04 ± 3.20 h, p = 0.211), caesarean delivery (22.2 versus 19.4%, p = 0.783), proportion of neonate with birth asphyxia (8.30 versus 8.30%, p = 1.00) and proportion of neonate admitted into special care baby unit (16.7 versus 13.9%, p = 0.872). Subgroup analysis of participants with 'ripe' cervix at initial pre-induction assessment showed that the mean induction to active phase of labour interval and mean induction to delivery interval were significantly shorter in Premaquick than transvaginal ultrasound group. Pre-induction cervical assessment at term with either Premaquick biomarkers or transvaginal ultrasound for cervical length is effective, objective and safe with similar and comparable outcome. However, when compared with women with positive transvaginal ultrasound at initial assessment, women with positive Premaquick test at initial assessment showed a significantly shorter duration of onset of active phase of labour and delivery of baby following induction of labour.

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

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