Cervical Length Measurement Research Articles

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.

Quantitative sonoelastography of the uterine cervix in predicting successful outcome of induction of labour.

The aim of the study was to evaluate the stiffness of cervix and determine its significance in predicting successful outcome of induction of labour. The primary objective was to determine the differences in elastography indices of different areas of cervix between the outcome groups of successful and failed induction of labour. A secondary objective was to find out the correlation of these elastography indices with Bishop's score and cervical length. This was a prospective, observational study conducted over a period of 6 months on pregnant women admitted in the labour room for induction of labour. Establishment of adequate regular uterine contractions - at least three contractions lasting 40-45 s in a 10-min period - was taken as end point for successful outcome of induction of labour. Even after 24 h of initiation of induction of labour, regular, adequate and painful uterine contractions were not established, then induction of labour was described as having failed. Prior to induction, cervical length measurement, Bishop's scoring and elastographic evaluation of the cervix were done by stress-strain elastography. A colour map was produced from purple to red and a five-step scale - the elastography index - was used to describe the various parts of the cervix. The differences between elastography indices of different parts of cervix were estimated using Mann-Whitney U test. Correlation of the indices with cervical length and Bishop's score was determined by Spearman's correlation coefficient. A total of 64 women were included in the study. A significant difference (p < 0.001) was found in the elastography index of internal os between the two outcome groups of success (1.76 ± 0.64) and failure (0.54 ± 0.18). However, the elastography index of central cervical canal, external os, anterior lip and posterior lips did not differ significantly across the outcome groups. A significant positive correlation was found between elastography index of internal os and cervical length (Spearman's correlation coefficient, r = 0.441, p < 0.001) and between elastography index of external os and cervical length (r = 0.347, p = 0.005), whereas a negative correlation was seen between elastography index of external os and Bishop's score (r = -0.270, p = 0.031). Elastography index of internal os can be used to predict outcome of induction of labour. Cervical elastography is a promising new technique for cervical consistency assessment. Further larger studies are required to determine some cut-off point for elastography index of internal os in prediction of outcome of induction of labour and to strongly establish the usefulness of cervical elastography for pregnancy management, preventing preterm delivery and establishment of cut-off points to determine successful induction.

“Bishop has left the building”-a randomized controlled trial to determine our modern induction needs

To compare the prediction value of full Bishop score to a “modified” Bishop score and cervical length measured by transvaginal sonography in nulliparous patients undergoing induction of labor at term. A prospective randomized controlled trial of patients admitted for labor induction at term at a single tertiary center between January 2019-December 2021. Patients were randomly assigned to one of the following groups: 1) induction based on full Bishop score; 2) induction based on cervical dilation and effacement alone (“modified” Bishop score); 3) induction based on sonographic cervical length measurements. We excluded patients from the final analysis if they were in active labor pre-induction, had a full Bishop score >5, >2 cm dilation or >80% effacement (“modified” Bishop score), or a cervical length< 20 mm, accordingly. The primary outcome was the rate of vaginal delivery. Secondary outcomes included induction to delivery interval, additional labor augmentation, pain assessment, and adverse maternal and neonatal outcomes. The final analysis included 758 patients. Vaginal delivery rate was similar in all three groups (84% vs. 81% vs 83%, P=0.68), along with the need for additional augmentation, and induction to delivery interval (71.4% vs. 72.3% vs. 70.3%, P=0.35, and 25.6±4.9 vs. 26.3±4.4 vs. 25.5±4.8, P=0.26, respectively). There were no significant differences in adverse maternal or neonatal outcomes between the groups. All 3 methods were similar as predictors of induction success (area under the curve 0.611 vs. 0.607 vs 0.615, P=0.023 vs. P=0.019 vs. P=0.017, respectively) with no significant difference between in test properties including sensitivity, specificity, positive and negative predictive values. Visual analogue scores were similar between the 3 tests (P=0.66). In nulliparous patients undergoing induction of labor, evaluating dilation and effacement alone is as efficient as full Bishop score or sonographic cervical length measurement in prediction of vaginal delivery success and induction to delivery interval with no significant difference in pain level.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Does a third trimester short cervix or change in cervical length predict preterm delivery?

To determine if a short cervical length (CL) defined as < 2.5cm beyond 28 weeks gestation and/or change in CL in patients with risk factors are associated with preterm delivery. This is an IRB exempt, retrospective chart review from 2015 to 2021. It includes all singleton gestations with symptoms/risk factors for preterm delivery who also had a CL evaluation via TVUS at our institution. Primary outcome was preterm delivery where we compared patients with a short CL of < 2.5 cm to those with a normal CL between 28-32 weeks. CL measurements were further categorized into CL < 2.0, < 1.5, and < 1.0 cm. Also, the change in CL between 20 and 28 weeks was determined. Data analysis was performed using t-test and Chi-square analysis for continuous variables and categorical values respectively. Odds ratios with 95% confidence interval were calculated for the primary outcome. Significant values are considered p < 0.05 Among 182 patients with third trimester CL evaluation, 47 patients (25.8%) had a CL < 2.5cm. Baseline demographics between the 2 groups were similar with respect to age, BMI, race, and prior preterm delivery. Table 1 demonstrates that when comparing the cohort with a short CL to a normal CL in the third trimester, no difference in preterm birth was noted at < 37 weeks, OR 1.86 (0.81, 4.28), < 34 weeks, OR 4.53 (0.73, 28.02), and < 32 weeks, OR 2.91 (0.18, 47.52). When evaluating CL < 1.5 cm, this was associated with an increased risk of preterm delivery (36.4% vs 11.7%, p < 0.05). Also, a greater average change in CL between 20 weeks and the third trimester was associated with preterm delivery (0.9 ± 0.94 vs. 0.5 ± 0.87, p < 0.05; Table 2). In singleton pregnancies, a short CL at < 2.5 cm or even less beyond 28 weeks gestational age is not associated with delivery < 37 weeks when compared to those with a normal CL. However, a short CL < 1.5 cm or change in CL of 0.9 cm or more may increase the risk of preterm birth. Larger studies should be done to evaluate this association.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Predictive Value of Cervical Length Measurement on Transvaginal Ultrasonography in Determination of Preterm Delivery in a Nigerian South Western Tertiary Hospital

Introduction: There has been an upsurge in the prevalence of preterm delivery globally and short cervix has been strongly associated with it. However, studies have shown that when it is detected early in mid-second trimester, preventive measures could be taken to forestall pregnancy loss. Materials and Methods: This prospective cohort study was conducted among pregnant women who presented for mid-trimester anomaly ultrasound scan between 18 and 24 weeks at the University College Hospital (UCH), Ibadan. The cervical length was measured with ultrasound machine through the transvaginal route and the patients were subsequently followed up till delivery. Results: One hundred and seventy-seven pregnant women with an age range between 21 and 44 years were recruited for the study. The incidence rate of mid-pregnancy short cervical length among the patients was 7.9%. The preterm delivery rate was 14.1%, and the association between it and short cervical length was statistically significant. The positive predictive value for preterm delivery when the &lt;2.5 cm cervical length cut-off was used was 44%, the negative predictive value was 97.3%. Conclusion: The incidence of preterm delivery due to ultrasonographically detected short cervical length was significant among the women attending antenatal clinic in UCH, and there was a significant association with some of the risk factors such as previous preterm delivery and previous preterm premature rupture of membranes.

Optimal gestational age at cervical length measurement for predicting preterm birth in low-risk women

Optimal gestational age at cervical length measurement for predicting preterm birth in low-risk women

Utility of cervical length measurement within 24 hours post transvaginal cervical cerclage placement

Utility of cervical length measurement within 24 hours post transvaginal cervical cerclage placement

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.

Are Cervical Length and Fibronectin Predictors of Preterm Birth after Fetal Spina Bifida Repair? A Single Center Cohort Study.

Background: A remaining risk of fetal spina bifida (fSB) repair is preterm delivery. This study assessed the value of preoperative cervical length (CL), CL dynamics (∆CL) and fetal fibronectin (fFN) tests to predict obstetric complications and length of stay (LOS) around fSB repair. Methods: 134 patients were included in this study. All patients had CL measurement and fFN testing before fSB repair. ∆CL within the first 14 days after intervention and until discharge after fSB repair were compared in groups (∆CL ≥ 10 mm/<10 mm; ≥20 mm/<20 mm). CL before surgery, ∆CL’s, and positive fFN tests were correlated to obstetric complications and LOS. Results: Mean CL before surgery was 41 ± 7 mm. Mean GA at birth was 35.4 ± 2.2 weeks. In the group of ∆CL ≥ 10 mm within the first 14 days after intervention, LOS was significantly longer (p = 0.02). ∆CL ≥ 10 mm until discharge after fSB was associated with a significantly higher rate of GA at birth <34 weeks (p = 0.03). The 3 positive fFN tests before fSB repair showed no correlation with GA at birth. Conclusion: Perioperative ∆CL influences LOS after fetal surgery. ∆CL ≥ 10 mm until discharge after fSB repair has a 3-times higher rate of preterm delivery before 34 weeks. Preoperative fFN testing showed no predictive value for preterm birth after fSB repair and was stopped.

The acceptability of cervical electrical impedance spectroscopy within a multi-modal preterm birth screening package: a mixed methods study

BackgroundReducing the rate of preterm birth is a cornerstone of global efforts to address child mortality, however existing screening tests offer imperfect prediction. Cervical electrical impedance spectroscopy (EIS) is a novel technique to quantify the ripening changes which precede labour. Mid-trimester EIS measurements have been shown to accurately predict preterm birth in asymptomatic women. This study aimed to comprehensively evaluate the acceptability of cervical EIS to low and high-risk women as part of a package of screening tests performed during a larger prospective trial.MethodsIn this parallel convergent mixed methods study, 40 women completed questionnaires before and after screening tests (EIS, cervical length measurement and fetal fibronectin quantification). Quantitative outcomes were anxiety levels before and after screening (Spielberger State Trait Anxiety Inventory, STAI-6), pain (Short Form McGill Pain Questionnaire) and ratings of EIS device appearance and test acceptability (visual analogue scales). Twenty-one women (11 high-risk, 10 low-risk) also attended a semi-structured qualitative interview. Interviews were recorded and transcribed, then thematic analysis was performed. A convergence coding matrix was constructed to enable triangulation of quantitative and qualitative results.ResultsHigh risk women demonstrated a significant reduction in anxiety following screening (mean STAI-6 score 34.5 vs. 29.0, p = 0.002). A similar trend was observed among low-risk participants. Ratings of pain, EIS device appearance and procedural acceptability did not differ between groups. Mean pain ratings were low (visual analogue scale 0.97 and 1.01), comparing favourably to published evaluations of conventional screening tests. Qualitative analysis provided insight into both the physical consequences and emotional experiences of screening. Additional determinants of the screening experience included device design, pre-existing perspectives on intimate examination, attitudes to knowledge in pregnancy and interaction with clinical staff. Finally, a range of practical considerations regarding wider use of EIS were identified, with valuable complementary detail regarding acceptability for use in antenatal care.ConclusionsCervical EIS is well tolerated and acceptable to both low and high-risk women when performed as part of a multi-modal screening package. These results provide useful insights to inform the design of future study and screening protocols.

Could Maternal Vitamin D Concentration Affect Cervical Length in Mid-Pregnancy? A Report From an Iranian Tertiary Center.

This descriptive-analytic cross-sectional study aimed to figure out whether maternal serum vitamin D concentration correlates with cervical length measurement in mid-gestation or not. During Jun-Jan 2021, 213 pregnant women at 18-22 weeks of gestation were investigated. First, demographic features were obtained then, maternal serum vitamin D concentration was measured by enzyme-linked immunoassay and cervical length was measured via transvaginal sonography according to fetal maternal foundation guideline and appropriate statistical test was used to analyze the correlation between maternal vitamin D level and cervical length in mid-pregnancy. It was shown that 29.6% and 25.4% of participants had vitamin D deficiency and insufficiency, respectively. Spearman's test found no significant correlation between maternal vitamin D level and cervical length in mid-pregnancy. Moreover, cervical length and maternal vitamin D level had no association with maternal BMI. Although maternal vitamin D level and its sufficiency status was not associated with cervical length in mid-pregnancy, as a trend toward decreased maternal serum vitamin D level by advancing gestational age was observed. It may be concluded that it is prolonged vitamin D deficiency during gestation that may lead to cervical length shortening and subsequent preterm delivery later in gestation.

Incidentally Found Midtrimester Shortened Cervical Length: Practice Patterns among American Maternal-Fetal Medicine Specialists.

The management of incidentally found short cervical length (CL) without prior spontaneous preterm birth (PTB) can vary. While most agree on starting vaginal progesterone, management after CL shortens <10 mm varies. The purpose of this study was to elucidate current practice patterns amongst maternal-fetal medicine (MFM) specialists. We conducted an online survey of MFM attending physicians and fellows in the United States from May 2019 to April 2020. The primary outcome was management of varying CL based on gestational age. Variations in management were assessed descriptively. There were 236 respondents out of 400 eligible surveyed, with a response rate of 59.2%. Universal CL screening was reported by 93.6% (49.6% abdominal and 44.1% transvaginal). Management of short CL varied based on CL measurement, rather than gestational age at presentation. At CL <10 mm, management included cerclage (17.4-18.7%), vaginal progesterone (41.3-41.7%), or cerclage plus vaginal progesterone (43.4%). Between CL of 10 to 20 mm, the majority (77.4-91.9%) would start vaginal progesterone. At CL 21 to 25 mm, management varied between expectant management (45.5-48.5%) or vaginal progesterone (51.1-52.8%). Suture material used was ethylene terephthalate (47.4%) or polypropelene (31.2). Preoperative antibiotic use was reported by 22.3%, while 45.5% used them only if the amniotic membranes were exposed, and 32.2% reported no antibiotic use. Postoperative tocolytic use varied with 19.3% reporting no use, 32.6% using it always, 8.2% only after significant cervical manipulation, 22.7% after the patient is experiencing symptoms, and 17.6% using it only if the cervix is dilated on exam. After cerclage placement, 44.5% continued CL surveillance. Substantial differences of opinion exist among MFM physicians regarding management of incidentally found short CL in patients without history of PTB. The differences in responses obtained highlight the need for evidence-based guidelines for managing this clinical scenario. · There is lack of consensus on the management of incidentally found shortened CL.. · The purpose of this study was to elucidate current trends in CL screening and management.. · Substantial differences of opinion exist regarding management of incidentally found short CL..

Oral supplementation of α-lipoic acid (ALA), magnesium, vitamin B6 and vitamin D stabilizes cervical changes in women presenting risk factors for preterm birth.

Recently, the PTB risk has been related to the objective measurement of cervical length (CL), since a CL of less than 25 mm is an accurate predictor of increased risk of PTB. Primary prevention of preterm labor is based on the early identification of symptoms and on pharmacological treatments with tocolytic drugs for inhibition of uterine contractions that are associated with a shortening of the cervix. Unfortunately, most of these drugs have important side effects. This study aimed to evaluate whether the administration of a combination of oral α-lipoic acid (ALA), magnesium, vitamin B6 and vitamin D to pregnant women presenting risk factors for PTB could reduce the rate of cervical shortening at 19-22 weeks of gestational age. A total of 122 women attending the first-trimester aneuploidy screening at 11-14 weeks of pregnancy and presenting risk factors for PTB were included in the study. Cervical length significantly decreased in the control group compared with the treatment group (-3.86 ± 1.97 vs. 1.50 ± 1.26; p=0.02). Although the rate of preterm birth did not significantly decrease (9.5% vs. 5.1%), admission for threatened PTB was statistically reduced in the treatment group compared with the control group (3.4% vs. 14.3%). Oral supplementation of ALA, magnesium, vitamin B6 and vitamin D significantly counteracted cervix shortening in pregnant women presenting risk factors for PTB.

Which part of cervical length is predictive of preterm birth in women with cerclage?

Objective To evaluate the predictive value of transvaginal ultrasonography measures: total cervical length (TCL), length to internal OS (LIO) and external OS (LEO) from the cerclage following cerclage placement, for spontaneous preterm birth (PTB). Methods A retrospective cohort at a single tertiary care center (2010–2020). Women with McDonald cerclage were evaluated during the 2nd and 3rd trimesters for cervical measurements: TCL, LIO, LEO. The primary outcome was PTB < 37 weeks. Demographic data, obstetric history, delivery information and serial cervical length measurements were collected. Subgroup analyses were performed to evaluate cervical length parameters (as described) and PTB rates prior to 34, 32 and 28 weeks of gestation. Results Of 66 women enrolled, 36.4% (n = 24) had PTB. There were no differences in the obstetrical history and demographic information (p > .05) nor indication for cerclage (p = .369). Cervical length measurements at 20–24 weeks demonstrated a shorter TCL & LIO (22.69 vs. 33.86 mm, p = .001; 9.25 vs. 15.9 mm, p = .0042; respectively) in the preterm group. The LEO was similar in both groups. This pattern was also shown in a subgroup analysis (PTB < 34, 32 and 28 weeks). Conclusion Cervical length from internal OS to cerclage and total cervical length have a predictive value for PTB in women with a cervical cerclage, regardless of the indication for cerclage/previous pregnancy outcomes. Our data emphasize the importance of follow-up cervical length measurements of women with a cervical cerclage, and especially cervical length from internal OS to cerclage as those women may need additional care.

Postpartum cervical length as a predictor of subsequent preterm birth—novel insights on an old enigma

Preterm birth poses one of the biggest challenge in modern obstetrics. Prediction of preterm birth has previously been based on patient history of preterm birth, short cervical length around midtrimester, and additional maternal risk factors. Little is known about cervical length and physiology during the postpartum period and any associations between postpartum cervical features and subsequent preterm birth. This study aimed to determine the feasibility and utility of postpartum cervical length measurements in prediction of subsequent spontaneous preterm birth. This was a prospective cohort study in a single tertiary center, conducted during a 5-year period (2017-2021). We evaluated the mean postpartum cervical length in patients after both preterm birth and term deliveries at 4 time periods: 8, 24, and 48 hours, and 6 weeks postpartum, with follow-up in their subsequent pregnancies to evaluate gestational age at delivery. The mean postpartum cervical length in different populations stratified by gestational age at delivery was assessed in phase 1 of the study, and the gestational age at subsequent delivery was assessed in phase2. A total of 1384 patients participated in phase 1. Mean postpartum cervical length was significantly shorter in the preterm birth (<34 weeks' gestation) group than in the term group at 8 hours (8.4±4.2 vs 22.3±3.5 mm; P<.0001), 24 hours (13.2±3.8 vs 33.2±3.1 mm; P<.0001), and 48 hours (17.9±4.4 vs 40.2±4.2 mm; P<.0001) postpartum. There was no significant difference in mean postpartum cervical length between the preterm birth group and the term group at 8, 24, and 48 hours postpartum. Cervical length was similar between the groups at 6 weeks postpartum. A total of 891 patients participated in phase 2. The area under the curve was higher for preterm birth screening based on a history of a short postpartum cervix alone than for a history of spontaneous preterm birth alone (0.66 [95% confidence interval, 0.63-0.69] vs 0.57 [95% confidence interval, 0.54-0.61]; P<.0001). Combining both a history of spontaneous preterm birth and a short postpartum cervix resulted in additional benefit, with an area under the curve of 0.74 (95% confidence interval, 0.73-0.84; P<.0001). Postpartum cervical length measurements may assist in detecting the group of patients at higher risk of subsequent spontaneous preterm birth. It may be beneficial to consider an increased follow-up regimen and earlier interventions in this group to reduce adverse perinatal outcomes.

Implications of training for pessary placement and accuracy of cervical length measurements after pessary placement: A prospective, double-blind, randomized clinical trial

BackgroundCervical pessary placement as an intervention for preterm birth prevention in women with a short cervix is a simple, painless procedure with few complications and a reasonable cost. Its efficacy depends on the expertise of the obstetrician performing the procedure. Therefore, it is reasonable to assume that untrained obstetricians with no expertise in pessary placement are more likely to insert the pessary incorrectly, thereby reducing its efficacy. Nevertheless, the impact of pessary placement expertise and training, as well as the accuracy of cervival length measurements, has never been evaluated. ObjectiveTo evaluate the impact of providing training for pessary placement to obstetricians with no expertise in this intervention. To this end, the percentage of correct pessary placements and accuracy of cervical length measurements after pessary placement achieved by obstetricians who received such training was compared with the results achieved by obstetricians who did not receive any training. MethodsThis prospective, double-blind, randomized clinical trial included 91 pregnant women requiring a cervical pessary due to a short cervix. Patients were assigned at random to a group treated by untrained obstetricians with no expertise in pessary placement (untrained group, n = 45) or to a group treated by trained obstetricians with no expertise in pessary placement (trained group, n = 46). The primary outcomes were the quality of pessary placement and the accuracy of cervical length measurements after pessary placement. ResultsObstetricians in the trained group achieved a significantly higher percentage of correct pessary placements than obstetricians in the untrained group (97.8 % and 65.2 %, respectively; p < 0.001). No significant differences were observed between groups in terms of the accuracy of cervical length measurements after pessary placement (p = 0.661), and both groups showed moderate to good agreement with the expert’s measurements (intraclass correlation coefficient 0.840 and 0.749, respectively). No differences in pregnancy outcomes were observed between groups. ConclusionThis study showed that providing training in pessary placement to obstetricians with no expertise in this procedure increases the quality of pessary placement. Furthermore, the inconsistent results found in pessary studies may be explained, in part, by a lack of training in pessary placement.

Cervical length screening for predicting preterm birth: A comparative review of guidelines.

A cervical length (CL) assessment may predict preterm birth (PTB). This study aimed to analyze and compare the recommendations of guidelines on the role of CL in the prediction of PTB. There is no consensus regarding universal screening of asymptomatic women without a history of prior spontaneous PTB (sPTB), using CL. On the other hand, CL assessment is recommended in cases with a history of sPTB due to the high recurrence rate. Finally, there is discrepancy regarding CL assessment in asymptomatic women with multiple pregnancy. Although far from perfect, CL measurement remains the best available method to predict PTB.

The predictive role of second trimester uterocervical angle measurement in obstetric outcomes.

Objective:Uterocervical angle has been suggested as a marker to predict preterm birth. However, the literature has limited data about its predictive role in preterm delivery. Moreover, no evidence is present to clarify the role of second-trimester uterocervical angle in induction success and postpartum hemorrhage. Here, it was aimed to compare the role of uterocervical angle with cervical length in predicting preterm labor and assess the utility of the second-trimester uterocervical angle in induction success and postpartum hemorrhage.Materials and Methods:A total of 125 pregnant women, hospitalized with a diagnosis of preterm labor were included in the study. Sonographic measurements of cervical length and uterocervical angle were performed between 16 and 24 weeks of gestation. The demographic, obstetric, laboratory, and sonographic features of the participants were recorded. Patients were divided into subgroups as preterm and term; with and without induction success; with and without postpartum hemorrhage. Additionally, preterm cases were divided into subgroups as early and late preterm. Variables were evaluated between the groups.Results:Cervical length was shorter in the preterm group (30.74±6.37 and 39.19±5.36, p<0.001). The uterocervical angle was 100.85 (85.2-147) in preterm and 88 (70-131) degrees in terms that were statistically significant (p<0.001). Furthermore, the uterocervical angle was wider [126 (100.7-147) and 98 (85.2-114), p<0.001] in the early preterm group. When the groups with and without postpartum bleeding were compared, no significant difference was detected in terms of uterocervical angle [96.5 (71-131) and 88 (70-147), p=0.164]. Additionally, the uterocervical angle was wider in the successful induction group (p<0.001). An a uterocervical angle >85 degrees predicted preterm delivery with 100% sensitivity and 45.54% specificity [area under the curve (AUC)=0.743, p<0.001]. When the cervical length and uterocervical angle were evaluated together to predict preterm delivery, no significant difference was found (p=0.086). An a uterocervical angle >88 degrees predicted induction success with 84.78% sensitivity and 79.75% specificity (AUC=0.887, p<0.001).Conclusion:Our study revealed that the uterocervical angle can be a useful marker in predicting preterm labor and induction success, although it does not predict postpartum hemorrhage.

Identification of Preterm Labor Evaluation Visits and Extraction of Cervical Length Measures from Electronic Health Records Within a Large Integrated Health Care System: Algorithm Development and Validation.

BackgroundPreterm birth (PTB) represents a significant public health problem in the United States and throughout the world. Accurate identification of preterm labor (PTL) evaluation visits is the first step in conducting PTB-related research.ObjectiveWe aimed to develop a validated computerized algorithm to identify PTL evaluation visits and extract cervical length (CL) measures from electronic health records (EHRs) within a large integrated health care system.MethodsWe used data extracted from the EHRs at Kaiser Permanente Southern California between 2009 and 2020. First, we identified triage and hospital encounters with fetal fibronectin (fFN) tests, transvaginal ultrasound (TVUS) procedures, PTL medications, or PTL diagnosis codes within 240/7-346/7 gestational weeks. Second, clinical notes associated with triage and hospital encounters within 240/7-346/7 gestational weeks were extracted from EHRs. A computerized algorithm and an automated process were developed and refined by multiple iterations of chart review and adjudication to search the following PTL indicators: fFN tests, TVUS procedures, abdominal pain, uterine contractions, PTL medications, and descriptions of PTL evaluations. An additional process was constructed to extract the CLs from the corresponding clinical notes of these identified PTL evaluation visits.ResultsA total of 441,673 live birth pregnancies were identified between 2009 and 2020. Of these, 103,139 pregnancies (23.35%) had documented PTL evaluation visits identified by the computerized algorithm. The trend of pregnancies with PTL evaluation visits slightly decreased from 24.41% (2009) to 17.42% (2020). Of the first 103,139 PTL visits, 19,439 (18.85%) and 44,423 (43.97%) had an fFN test and a TVUS, respectively. The percentage of first PTL visits with an fFN test decreased from 18.06% at 240/7 gestational weeks to 2.32% at 346/7 gestational weeks, and TVUS from 54.67% at 240/7 gestational weeks to 12.05% in 346/7 gestational weeks. The mean (SD) of the CL was 3.66 (0.99) cm with a mean range of 3.61-3.69 cm that remained stable across the study period. Of the pregnancies with PTL evaluation visits, the rate of PTB remained stable over time (20,399, 19.78%). Validation of the computerized algorithms against 100 randomly selected records from these potential PTL visits showed positive predictive values of 97%, 94.44%, 100%, and 96.43% for the PTL evaluation visits, fFN tests, TVUS, and CL, respectively, along with sensitivity values of 100%, 90%, and 90%, and specificity values of 98.8%, 100%, and 98.6% for the fFN test, TVUS, and CL, respectively.ConclusionsThe developed computerized algorithm effectively identified PTL evaluation visits and extracted the corresponding CL measures from the EHRs. Validation against this algorithm achieved a high level of accuracy. This computerized algorithm can be used for conducting PTL- or PTB-related pharmacoepidemiologic studies and patient care reviews.

OP08.08: Deep learning‐based automated measurement of cervical length in transvaginal ultrasound images of pregnant women

OP08.08: Deep learning‐based automated measurement of cervical length in transvaginal ultrasound images of pregnant women