Evaluation of antenatal care quality for preterm birth prevention using an auditable scoring system: A retrospective, descriptive, longitudinal study in Sydney, Australia.

INTRODUCTION: Preterm birth continues to be one of the most significant contributors to perinatal death. This study aims to evaluate the quality of antenatal care provided to women delivering preterm. METHODS: This was a retrospective, descriptive, longitudinal review of all women who had antenatal care within a single Australian tertiary hospital and delivered spontaneously between 24 and 37 weeks of gestation, using an auditable scoring system assessing potential interventions for prevention of preterm birth. The review was limited to singleton pregnancies without fetal abnormalities delivering between January 2013 and April 2015. The audit tool was developed by reference to established 'best practice' guidance for prediction and prevention of preterm birth based on Royal Australian and New Zealand College of Obstetricians and Gynaecologists guidelines and published literature. Different pathways were assessed for women deemed either low- or high-risk at the outset of antenatal care. RESULTS: A series of 161 pregnancies that delivered preterm (between 24 and 37 weeks' gestation) were reviewed. The quality of antenatal care was scored 'good' in 42.9% and 50% of high-risk and low-risk women, respectively. Care was scored 'adequate', with room for improvement in 51.4% and 45.2% of the two corresponding groups. The main deficiencies in care were recorded evidence of assessment of cervical length (absent in 35% of cases) and failure to screen for bacterial vaginosis in high-risk women. CONCLUSIONS: Auditing antenatal care for prevention of preterm birth allows identification of suboptimal practice allowing service improvement and potential intervention for preterm birth prevention.

Cervical length evolution in pregnancy and prediction of preterm delivery.

PURPOSE: To construct reference charts for cervical length (CL) in pregnancy based on longitudinal measurements and to assess the value of measuring cervical length after 24 weeks of gestation. METHODS: CL was measured transvaginally in singleton pregnancies at 5 to 41 weeks. Pregnancies with more than one measurement were used for creating the CL chart, whereas any measurement after 24 weeks was considered for assessing the correlation of CL with preterm delivery. RESULTS: The dataset consisted of 12,601 pregnancies and 33,899 observations. Gestational age was the main predictor of CL (R2 = 67.3%). Further adjustments in the fixed effects part for maternal characteristics (age, BMI, smoking status, parity, history of miscarriage, and cervical surgery) improved the prediction ability (R2 = 78.4%). CL was predictive of spontaneous preterm delivery before 37 weeks when measured at any gestation between 24 and 35 weeks and it was predictive of spontaneous preterm delivery before 32 weeks when measured between 28 and 31 weeks (AUC = 0.68). CONCLUSION: Gestational age is the main predictor of CL followed by maternal characteristics and history. CL assessment between 24 and 35 + 6 weeks can enhance our ability to predict spontaneous preterm delivery.

A novel technique for the measurement of cervical length in non-pregnant women.

Introduction: Cervical elongation is considered a risk factor for pelvic organ prolapse treatment failure in uterine preservation surgery. Consensus has not been reached regarding what is considered a normal cervical length, or how to measure it. Our primary aim was to test a new technique for measuring cervical length. Materials and Methods: We enrolled women undergoing hysterectomy, with or without pelvic organ prolapse (for all indications except cervical tumours/history of cervical operations). Their cervical lengths were measured both by ultrasound and anatomical measurement. The external length of the cervix was measured using Doppler location of the uterine artery near the cervical-uterine junction as the proximal point and compared to the ultrasound measurement of the cervical canal. The uterine specimen was used to record anatomical cervical measurements as well as uterine corpus length. Baseline characteristics such as age, body mass index and pelvic organ prolapse quantification were also collected. Results: Twenty women were eligible for evaluation. We found the average anatomical cervical canal length was (ccAN) 33.95 mm (range ± 9.23) and by external measurement (ceAN) 36.80 mm (range ± 7.54). We found a significant, high-powered correlation between our ultrasound and anatomical measurements in both techniques, as well as between the two ultrasound techniques. We also found a negative correlation between cervical length and women's age (rp = -0.443, P = 0.05). Conclusion: Transvaginal ultrasound measurement of cervical length using the location of the uterine artery was found to have a strong correlation to the anatomical cervical length and can be used for the measurement of normal cervical length.

Predictive value of short cervix in early third trimester for preterm birth in women with normal mid-trimester cervical length.

BACKGROUND: Short cervical length in the mid-trimester is a powerful predictor of preterm birth (PTB). However, clinical significance of cervical length in the third trimester for predicting PTB has not been established yet. OBJECTIVE: To examine the predictive role of a shortened cervix in the third trimester for PTB in women who had a normal cervical length in the second trimester STUDY DESIGN: This retrospective cohort study included women who underwent cervical length measured at least once in both the second trimester (16+0 weeks to 27+6weeks) and the early third trimester (28+0 weeks to 33+6 weeks). Women with short cervical length in the second trimester, those with multiple pregnancies, those who underwent cerclage operation, and those who had iatrogenic PTB were excluded. The study population was divided into two groups based on cervical length in the third trimester: a short cervix (≤25 mm) group and a control group (>25 mm). Rates of PTB (<37 weeks) were compared between two groups. Predictive performances of cervical length in the third trimester for PTB were assessed. RESULTS: Women with a short cervical length at 28+0 to 33+6 weeks accounted for 12.6% (n=717) of the total study population (n=5682). PTB rate was 9.5% in the short cervix group, which was significantly higher than that (3.2%) in the control group (P<.001). The adjusted odds ratio for short cervical length on PTB was 2.73 (95% CI: 1.96-3.79). A short cervix in the third trimester had a sensitivity of 30.1%, a specificity of 88.1%, a positive predictive value of 9.5%, and a negative predictive value (NPV) of 96.8% in predicting PTB. The addition of third-trimester cervical length to the predictive model significantly increased the area under the curve from 0.64 (95% CI: 0.60-0.68) to 0.67 (95% CI: 0.63-0.71) (P=.002), demonstrating improved predictive performance. CONCLUSION: Approximately 13% of women with normal cervical length in the mid-trimester had a short cervical length after 28 weeks, which increased the risk of PTB. The high specificity and NPV of third-trimester cervical length measurements underscore their critical utility in identifying women at low risk for preterm delivery.

The predictive value of transvaginal cervical length and cervical angle ultrasonography in term delivery outcomes: a cohort study.

BACKGROUND: Various techniques have been proposed to predict and evaluate the timing and conditions of childbirth in pregnant women at different stages of pregnancy. Providing precise methods for forecasting childbirth status can reduce the burden on the healthcare system. This study aimed to evaluate the predictive value of transvaginal sonography of cervical length (CL) and cervical angle (CA) on full-term delivery outcomes. METHODS: This cohort study analyzed 151 pregnant women between 37 and 42 weeks of gestational age who were treated at Rasoul Akram Hospital affiliated with Iran University of Medical Sciences from June 2023 to January 2024. All Participants received transvaginal examinations. This study evaluated the accuracy of CL and CA by transvaginal sonography in predicting outcomes like vaginal delivery, cesarean section, necessity for labor induction, and the rate of Premature Rupture of Membranes (PROM). The study used the Receiver Operating Characteristic (ROC) curve to determine the optimal cutoff for predicting birth outcomes. RESULTS: The mean age of the pregnant women was 28.9 ± 4.22 years, while the average duration of pregnancy was 39.8 ± 2.11 weeks. Cesarean delivery was performed on 45 individuals (29.8%) and 106 (70.1%) underwent vaginal delivery. The mean CL overall stood at 21.2 ± 6.4 mm. PROM was observed in 41 cases (27.1%) among full-term pregnancies. A significant difference was noted in mean CL between the cesarean and vaginal delivery groups (24.2 ± 2.4 vs. 20.1 ± 2.1 mm, p = 0.001). The predictive value of a CL measuring 21 mm for cesarean delivery was 72.2% sensitive and 79.1% specific. Similarly, a CL of 22 mm showed 66.6% sensitivity and 80.2% specificity for labor induction. Regarding PROM in full-term pregnancies, a CL assessment demonstrated 59.8% sensitivity and 69.1% specificity. Finally, a CA of 115.2° exhibited 70.3% sensitivity and 78.4% specificity in predicting vaginal delivery. CONCLUSION: The present study showed that evaluating CL and CA via transvaginal sonography demonstrated adequate diagnostic accuracy in predicting spontaneous birth, need for labor induction, cesarean delivery, and incidence of PROM in full-term pregnant women. This method is suggested to be an accurate and appropriate way to predict delivery results.

The impact of cut-off values on the prevalence of short cervical length in pregnancy.

BACKGROUND: A prior study suggested that implementing a cut-off value of ≤30 mm for a short cervical length (CL) could potentially introduce selection bias and alter the distribution of CL measurements. As such, the objective of this study is to evaluate how CL distribution and incidence of short CL are affected when using different cut-off values for a short CL. STUDY DESIGN: This is a secondary analysis of the Quadruple P (QP) Screening study; a prospective cohort study that included low-risk patients with singleton pregnancies undergoing fetal anomaly scan at 18-22 weeks of gestation, including a CL measurement. Patients with a short cervix, defined as ≤35 mm, were subsequently counseled for the QP trial; a randomized controlled trial (RCT) comparing progesterone to cervical pessary for the prevention of preterm birth. If participation to the RCT was refused, patients with a CL ≤25 mm were advised to use progestogen. The primary objective of this current study was to assess the normal distribution of CL across the entire cohort and to assess the incidence of short CL when using the cut-off values of ≤35 and ≤25 mm. Normal distributions for CL were simulated based on mean and standard deviation(SD) of the original data. The Kolmogorov-Smirnov test was used to evaluate the distribution of the CL measurements. Moreover, to evaluate the motives behind ultrasound measurements around the cut-off value, sonographers were asked to fill out a qualitative questionnaire. RESULTS: The total cohort included 19.171 eligible participants who underwent CL measurement, with a mean CL of 43.9 mm (±8.1 SD). The distribution of all CL observed measurements deviated significantly from the normal distribution (p < 0.001). A total of 1.852 (9.7%) patients had short CL ≤35 mm, which was significantly lower than expected when compared to the simulated normal distribution (n = 2.661, 13.9%; p < 0.001). The incidence of short CL ≤25 mm in our cohort statistically differed from the simulated normal distribution (238, 1.2% vs 177, 0.9%; p=0.003). When comparing our data to the simulated normal distribution, the difference in distributions is most pronounced when examining the difference between 35 and 36 mm. Results of the questionnaire reveal sonographers claimed not to be influenced by a cut-off value for study participation or progesterone treatment. CONCLUSION: This study demonstrates that using any cut-off value for a short CL influences the incidence and distribution of CL. When using a cut-off value of ≤35 mm for study inclusion, the incidence of measurements of a short CL is lower than the anticipated incidence compared to a normal distribution. However, when using a cut-off value of ≤25 mm for progesterone treatment, the frequency of CL measurements is higher than expected below this threshold compared to a normal distribution. This study highlights the risk of introducing selection bias, most likely unintentionally, when cut-off values for short CL are used, regardless of the specific value chosen. Therefore healthcare providers should measure the CL with caution if essential decisions depend on a specific cut-off value.

A prediction model based on MRI and ultrasound to predict the risk of PAS in patient with placenta previa.

INTRODUCTION: To investigate the risk factors affecting patients with placenta previa (PP) and to construct an effective prediction model for the severity of PAS in PP. METHODS: A total of 240 pregnant women with PP were enrolled in this study. An MRI+Ultrasound-based model was developed to classify patients into placental implantation and non-placental implantation groups. Multivariate nomograms were created based on imaging features. The model was evaluated using Receiver Operating Characteristic (ROC) curve analysis. The predictive accuracy of the nomogram was assessed through calibration plots and decision curve analysis. RESULTS: The MRI+Ultrasound-based prediction model demonstrated favorable discrimination between the placental implantation and non-placental implantation groups. The calibration curve exhibited agreement between the estimated and actual probability of placental implantation. Additionally, decision curve analysis indicated a high clinical benefit across a wide range of probability thresholds. The Area under the ROC curve (AUC) was 0.911 (95 % CI: 0.76-0.947), with a sensitivity of 88.40 % and specificity of 88.10 %. CONCLUSION: The MRI+Ultrasound-based prediction model could be a valuable tool for preoperative prediction of the percentage of implantation. Our study enables obstetricians to conduct more adequate preoperative evaluations.

The Effect of Maternal Parity on Preterm Birth Risk in Women with Short Mid-Trimester Cervical Length: A Retrospective Cohort Study.

Objectives: To evaluate the effect of maternal parity on the association between mid-trimester cervical length and preterm birth to elucidate the potential intricacies of this relationship. Methods: A retrospective cohort study using Electronic Medical Records (EMR) data. The study population included pregnant women with a singleton fetus and a short mid-trimester cervical length, recorded in the EMR system at a large health maintenance organization. Women were categorized by parity in the current pregnancy, and a statistical analysis was conducted to examine the relationship between parity and premature delivery. Results: Data were collected from 1144 records of cervical length measurements of 738 pregnancies obtained from the HMO database. The study population consisted of 259 nulliparous women (35.1%), 451 multiparous women (61.1%), and 28 grand multiparous women (3.8%). The results from the multivariate analysis of the primary outcome showed that nulliparity was significantly associated with an increased risk of premature delivery, with a risk of 1.557 for nulliparous women compared to parous women. Conclusions: In this study, a statistically significant association was found between nulliparity and preterm birth among women with a short mid-trimester cervical length. Nulliparous women were found to have a higher risk of preterm birth in the current pregnancy compared to parous women. Further research is needed to understand the underlying mechanisms and to develop targeted interventions to reduce the risk of premature birth in this population. These findings highlight the need to consider nulliparity as a potential risk factor in the management of pregnancies with a shortened cervix.

Association between miRNAs in serum at 10-14 gestational weeks and spontaneous preterm delivery.

INTRODUCTION: Preterm delivery (PTD) is the leading cause of death in children under 5 years of age. Cervical shortening detected by ultrasound can be used to predict PTD, but prediction is not perfect, and complementary diagnostic markers are needed. Recently, specific plasma microribonucleic acid (miRNAs) detected in early second trimester were shown to be associated with spontaneous PTD in high-risk women with a singleton pregnancy. The aim of this study was to explore to what extent these miRNAs are associated with spontaneous PTD and cervical length in a general population. MATERIAL AND METHODS: This study is a nested case-control study within the CERVIX study. The CERVIX study evaluated the ability of cervical length screening with transvaginal ultrasound to identify women at risk of PTD. In the present study, women who delivered spontaneously <34 weeks (n = 61) were compared with a control group of women who delivered at full term (39 + 0 to 40 + 6 gestational weeks, n = 205). Archived serum samples were analyzed with RT-qPCR for miRNA expression levels of let-7a-5p, miR-150-5p, miR-15b-5p, miR-185-5p, miR-191-5p, miR-19b-3p, miR-23a-3p, miR-374a-5p, and miR-93-5p. The mean relative expression was compared between the groups. Sub-analyses were performed for women delivering <32, <30, and <28 weeks vs the full-term group. RESULTS: The analyzed miRNAs were not significantly differentially expressed in women delivering <34 weeks compared to those delivering at full term. MiR-191-5p and miR-93-5p were significantly overexpressed in women who delivered <32 weeks, and further increase in fold change was observed with decreasing gestational age at delivery. The level of miR-15b-5p was significantly higher in women delivering at <30 weeks compared to those delivering at full term. CONCLUSIONS: Our study shows that overexpression of miR-93-5p, miR-15b-5p, and miR-191-5p in serum at early gestation is associated with spontaneous PTD in a general population. Further research is needed to evaluate the potential of these miRNAs as future biomarkers for spontaneous PTD, as well as their pathophysiological role in spontaneous PTD.

Uterocervical angle and cervical length measurements for spontaneous preterm birth prediction in low-risk singleton pregnant women: a prospective cohort study.

PURPOSE: Preterm birth is the leading cause of early neonatal morbidity and mortality. Strategies to predict preterm birth risk can help improve pregnancy outcomes. Even pregnant women without known risk factors for preterm birth can also experience it. This study aimed to evaluate the ability of the uterocervical angle and cervical length to predict spontaneous preterm birth in low-risk singleton pregnant women. METHODS: A prospective study on 1107 singleton pregnant women between 16+0 and 23+6 weeks gestation at low risk for spontaneous preterm birth who were treated at the Haiphong Hospital of Obstetrics and Gynecology, Vietnam, between September 2020 and September 2021 was conducted. A single sonographer assessed the cervical length and the uterocervical angle using transvaginal ultrasonography. The patients were followed up until delivery to determine the main pregnancy outcome (spontaneous preterm birth before 37 weeks gestation). The cut-off points for the uterocervical angle and cervical length were established by analyzing the receiver operating characteristic curve. The sensitivity, specificity, likelihood ratio, positive and negative predictive values, and accuracy of the uterocervical angle and cervical length for predicting spontaneous preterm birth were determined. RESULTS: A uterocervical angle ≥ 99° predicted spontaneous preterm birth at < 37 weeks, with a sensitivity and specificity of 91% and 76%, respectively. A cervical length ≤ 33.8 mm predicted preterm birth at < 37 weeks with a sensitivity and specificity of 25% and 66%, respectively. A uterocervical angle ≥ 99° combined with a cervical length ≤ 33.8 mm yielded the sensitivity, specificity, positive predictive value, likelihood ratio, and accuracy of spontaneous preterm birth prediction of 66%, 93%, 36%, 9, and 91%, respectively; thus provided a significant increase of specificity with an acceptable reduction of sensitivity as compared to cervical length alone. CONCLUSION: Besides the cervical length, the uterocervical angle can be considered a valuable ultrasound parameter for predicting spontaneous preterm birth in low-risk singleton pregnant women. Combining the uterocervical angle and cervical length yielded stronger spontaneous preterm birth prediction values.

Performance of the First-Trimester Cervical Consistency Index to Predict Preterm Birth.

Background/Objectives: Preterm birth (PTB) remains a significant global health challenge. Previous attempts to predict preterm birth in the first trimester using cervical length have been contradictory. The cervical consistency index (CCI) was introduced to quantify early cervical changes and has shown promise across various clinical scenarios in the mid-trimester, though testing in the first trimester is lacking. This study aims to assess the cervical consistency index performance in predicting preterm birth during the first trimester of pregnancy. Methods: In this prospective cohort study, focused exclusively on research, women with singleton pregnancies, both with and without a history of spontaneous preterm birth (sPTB), were included. The primary outcome was sPTB before 37 weeks, with a secondary outcome of sPTB before 34 weeks. CCI measurements were taken between 11+0 to 13+6 weeks of gestation. Receiver operating characteristic (ROC) curves were generated, and sensitivity and specificity were calculated for the optimal cut-off and for the 5th, 10th, and 15th percentile. Intraobserver and interobserver agreements were assessed using the intraclass correlation coefficient (ICC). Results: Among the 667 patients analyzed, the rates of sPTB before 37 and 34 weeks were 9.2% (61/667) and 1.8% (12/667), respectively. The detection rates (DRs) for CCI predicting PTB before 37 and 34 weeks were 19.7% (12/61) and 33.3% (4/12). Negative predictive values were 91.8% (546/595) and 98.7% (588/596), while the areas under the curve (AUC) for sPTB before 37 and 34 weeks were 0.62 (95% CI: 0.54-0.69) and 0.80 (95% CI: 0.71-0.89), respectively. Of the 61 patients with preterm birth, 13 (21.3%) had a preterm birth history; in this group, the CCI percentile 10th identified 39% (5/13). Intraobserver ICC was 0.862 (95% CI: 0.769-0.920), and interobserver ICC was 0.833 (95% CI: 0.722-0.902). Conclusions: This study suggests that utilizing CCI in the first trimester of pregnancy could serve as a valuable tool for predicting preterm birth before 34 weeks of gestation, demonstrating robust intraobserver and interobserver reliability.

Is There Utility in Transvaginal Cervical Length Surveillance After Cerclage Placement for the Prediction of Spontaneous Preterm Birth?

INTRODUCTION: Transvaginal cervical length (TVCL) surveillance post-transvaginal cerclage placement is not universally performed, despite the correlated risk of short TVCL with spontaneous preterm birth (sPTB). This study evaluated if patients with a TVCL <2.5 cm after cerclage placement had higher odds of sPTB than those with a TVCL ≥2.5 cm after cerclage placement. METHODS: This retrospective cohort study included patients with a singleton, non-anomalous gestation with a transvaginal cerclage who had TVCL surveillance post-cerclage placement. The primary outcome was the odds of sPTB among patients with TVCL <2.5 cm vs TVCL ≥2.5 cm after cerclage placement. Transvaginal cerclage placement indications included history indicated, physical exam indicated, and ultrasound indicated. Outcomes were assessed using univariate and multivariate analysis while adjusting for progesterone use, TVCL before cerclage placement, and cerclage indication. RESULTS: The analysis included 210 patients, and the sPTB rate was 46.7%. Those with sPTB underwent cerclage placement at later gestational ages, had higher rates of exam-indicated cerclage, and were more likely to be prescribed vaginal progesterone. Patients with a TVCL of <2.5 cm after cerclage placement did not have significantly increased odds of sPTB (OR: 2.8, 95% CI: 0.9-8.7, p=0.07); however, patients with a TVCL <2.0 cm had significantly increased odds of sPTB (OR: 6.3, 95% CI: 2.2-18.8, p<0.001). CONCLUSION: In patients with transvaginal cerclage, there does not appear to be increased odds of sPTB with TVCL <2.5 cm after cerclage placement; however, there does appear to be an increased odds of sPTB in patients with a TVCL of <2.0 cm after cerclage placement.

Routine transabdominal cervical length screening in mid-pregnancy for the prevention of preterm birth: Is it good enough to use as a screening test?

BACKGROUND: Preterm birth (PTB) is a major pregnancy complication. There is evidence that a short cervical length in mid-pregnancy may predict women at increased risk of PTB. AIMS: To evaluate the utility of population-based, transabdominal cervical length (TACL) measurement screening in mid-pregnancy for PTB prediction in women. MATERIALS AND METHODS: A transabdominal approach was initially performed, with a transvaginal (TVCL) approach offered when the TACL was <35 mm, could not be accurately measured, or the pregnancy had risk factors for PTB. TACL was compared to the directly related TVCL, when both were performed at the same assessment. Women with risk factors of PTB were included when they had both TACL and TVCL measurements performed at the same visit. RESULTS: Data were provided for 9355 singleton pregnancies from 13 participating imaging centres. A transabdominal approach was used in 9006 (96.3%), including 682 (7.3%) TVCL combined with TACL. There were 349 (3.7%) women who had TVCL only. The median TACL was longer (40 mm) than the TVCL (38 mm). In 682 paired TACL and TVCL measurements, TACL <35 mm correctly identified 96.2% of pregnancies with TVCL <25 mm, compared with 65.4% of cases when using a TACL <30 mm. A TVCL <25 mm occurred in 59 (0.6%) women. A TACL <35 mm was associated with birth <37 weeks of gestation in 12.1% of women and birth <32 weeks of gestation in 3.9%. CONCLUSIONS: Universal TACL is a feasible option for population screening of cervical length in a low-risk population, progressing to TVCL if the TACL is <35 mm or the cervix cannot be transabdominally accurately measured.

Comparative analysis of obstetric, perinatal, and neurodevelopmental outcomes following chorionic villus sampling and amniocentesis.

Background: The risks of invasive prenatal tests are reported in previous studies such as miscarriage, fetal anomalies, and bleeding. However, few compare short-term and long-term outcomes between invasive tests. This study aims to investigate obstetric, perinatal, and children's neurodevelopmental outcomes following chorionic villus sampling (CVS) or amniocentesis in singleton pregnancy. Methods: This retrospective cohort study included healthy singleton pregnancies underwent transabdominal CVS (gestational age [GA] at 10-13 weeks) or amniocentesis (GA at 15-21 weeks) at a single medical center between 2012 and 2022. Only cases with normal genetic results were eligible. Short-term and long-term neurodevelopmental outcomes were evaluated. Results: The study included 200 CVS cases and 498 amniocentesis cases. No significant differences were found in body mass index, parities, previous preterm birth, conception method, and cervical length (CL) before an invasive test between the groups. Rates of preterm labor, preterm premature rupture of the membranes, preterm birth, neonatal survival, neonatal short-term morbidities, and long-term neurodevelopmental delay were similar. However, the CVS group had a higher rate of cervical cerclage due to short CL before 24 weeks (7.0%) compared to the amniocentesis group (2.4%). CVS markedly increased the risk of cervical cerclage due to short CL (adjusted odd ratio [aOR] = 3.17, 95%CI [1.23-8.12], p = 0.016), after considering maternal characteristics. Conclusion: Performing CVS resulted in a higher incidence of cerclage due to short cervix or cervical dilatation compared to amniocentesis in singleton pregnancies. This highlights the importance of cautious selection for CVS and the necessity of informing women about the associated risks beforehand.

TVS-guided cervical strain elastography is more effective than measuring cervical length as an independent predictor of spontaneous preterm delivery in asymptomatic, high-risk women during the mid-trimester.

INTRODUCTION: TVS (Transvaginal Sonography) guided Cervical strain elastography (CSE) is now available in tertiary referral centers of LMICs (Low- and Middle-Income Countries). TVS cervical length (CL) assessment is being used routinely. Still, elastography is not used in clinical settings, although enough evidence suggests good predictive value towards sPTD (spontaneous Preterm Delivery). The clinical utility of elastography has not been tested among high-risk populations of LMICs for the prediction of sPTD. AIM: To test the performance of TVS-CSE in predicting sPTD among asymptomatic women in the mid-trimester at risk of sPTD either due to clinical factors or due to a short cervix. METHOD: Prospective observational study performed at a tertiary hospital in South India. Asymptomatic pregnant women between 16 and 24 weeks who had one or more clinical risk factors for sPTD or CL <2.5 cm were included. GE Voluson E-8 ultrasound machine was used. After CL measurement, elastography color coding was noted around the internal-os in the sagittal view. The strain ratio (SR) was calculated using the trace method on three ROIs (Region of Interest): Internal-os in sagittal view (IN), whole cervix in sagittal view (WN), and internal-os in axial view (AN). Reference Tissue (RT) of similar size and depth was chosen in the darkest blue region on elastography (stiffest area) outside the cervix, posterior/lateral to the cervix over the ligament insertion. Lower the SR - softer the cervix. Two trained fetal medicine consultants performed the initial 57 cases until intra/inter-observer correlation was satisfactory. Delivery before 37 weeks (after 26 weeks), in which the process of labor has begun spontaneously, or labor was induced after PPROM-was considered as sPTD. SRs were assessed to determine how well they could predict sPTD independently or combined with cervical length. RESULTS: Out of 221 recruited,17 were lost to follow-up after 32 weeks; 204 were delivered in our hospital. Irrespective of the route of delivery, 71 (34.8%) had sPTD. Of the remaining 133, 106 delivered at term, and 27 underwent medically indicated PTD. Apart from multiple pregnancies, no other preterm-related risk factors (including CL < 2.5 cm) showed significant association with sPTD. Red CSE pattern around internal-os was associated with a significantly higher (54.5%) incidence of sPTD. CLs were similar (3.63 ± 0.67 vs. 3.63 ± 0.80, p = .981) whereas SRs in all three ROIs were significantly lower among sPTD group versus no sPTD group (IN:0.65 ± 0.29 vs 0.79 ± 0.30 p = .001, WN:0.34 ± 0.13 vs 0.39 ± 0.15, p = .013, AN:0.37 ± 0.16 vs 0.48 ± 0.26, p = .002, respectively). Using ROC curves, while CL was not predictive (AUROC 0.49, p = .81), SRs showed moderate predictive value toward sPTD with the best AUC of 0.624 (p = .003) at IN. Prediction was slightly better for early sPTD <32 weeks (AUC 0.653 p = 0.03). The best cutoff for SR at IN was 0.72, below which there was a moderate accuracy in predicting sPTD (sensitivity 52.11%, specificity 60.9%, PPV 41.57%, NPV 70.44%, diagnostic OR 1.69 and overall accuracy of 57.84%). A weak positive correlation is seen between IN and CL (Pearson's correlation R = 0.181). Multi-variable binary logistic regression analysis suggested that SRs at IN (Adjusted OR - 0.259 CI 0.079-0.850), AN (Adjusted OR 0.182 CI 0.034-0.963), Multiple Pregnancy (Adjusted OR 3.5 CI 1.51-8.13) and previous sPTD/PPROM (Adjusted OR 2.72 CI 0.97-7.61) independently predicted sPTD. CONCLUSIONS: TVS CSE performed better than CL as an independent predictive tool toward sPTD, although predictive efficacy was modest at best. Since technology is now available in high-end USG machines in tertiary care centers, we propose optimal utilization of CSE in LMICs to triage at-risk populations since low SRs are strongly associated with sPTD.

A machine learning model to predict spontaneous vaginal delivery failure for term nulliparous women: An observational study.

OBJECTIVE: This study aims to construct and evaluate a model to predict spontaneous vaginal delivery (SVD) failure in term nulliparous women based on machine learning algorithms. METHODS: In this retrospective observational study, data on nulliparous women without contraindications for vaginal delivery with a singleton pregnancy ≥37 weeks and before the onset of labor from September 2020 to September 2021 were divided into a training set and a temporal validation set. Transperineal ultrasound was performed to collect angle of progression, head-perineum distance, subpubic arch angle, and their levator hiatal dimensions. The cervical length was measured via transvaginal ultrasound. The delivery methods were later recorded. Through LASSO regression analysis, indicators that can affect SVD failure were selected. Seven common machine learning algorithms were selected for model training, and the optimal algorithm was selected based on the area under the curve (AUC) to evaluate the effectiveness of the validation model. RESULTS: Four indicators related to SVD failure were identified through LASSO regression screening: angle of progression, cervical length, subpubic arch angle, and estimated fetal weight. The Gaussian NB algorithm was found to yield the highest AUC (0.82, 95% confidence interval [CI] 0.65-0.98) during model training, and hence it was chosen for verification with the temporal validation set, in which an AUC of 0.79 (95% CI 0.64-0.95) was obtained with accuracy, sensitivity, and specificity rates of 80.9%, 72.7%, and 75.0%, respectively. CONCLUSION: The Gaussian NB model showed good predictive effect, proving its potential as a clinical reference for predicting SVD failure of term nulliparous women before actual delivery.

Pregnancy outcomes of cerclage in twin gestations: a multicenter retrospective cohort study.

OBJECTIVES: To determine the effects of cerclage on twin pregnancies. METHODS: A multicenter, retrospective, cohort study was conducted at 10 tertiary centers using a web-based data collection platform. The study population included twin pregnancies delivered after 20 weeks of gestation. Patients with one or two fetal deaths before 20 weeks of gestation were excluded. Maternal characteristics, including prenatal cervical length (CL) and obstetric outcomes, were retrieved from the electronic medical records. RESULTS: A total of 1,473 patients had available data regarding the CL measured before 24 weeks of gestation. Seven patients without CL data obtained prior to cerclage were excluded from the analysis. The study population was divided into two groups according to the CL measured during the mid-trimester: the CL ≤2.5 cm group (n = 127) and the CL >2.5 cm group (n = 1,339). A total of 127 patients (8.7%) were included in the CL ≤2.5 cm group, including 41.7% (53/127) who received cerclage. Patients in the CL >2.5 cm group who received cerclage had significantly lower gestational age at delivery than the control group (hazard ratio (HR): 1.8; 95% confidence interval (CI): 1.11-2.87; p = .016). Patients in the CL ≤2.5 cm group who received cerclage had a significantly higher gestational age at delivery than the control group (HR: 0.5; 95% CI: 0.30-0.82; p value = .006). CONCLUSIONS: In twin pregnancies with a CL ≤2.5 cm, cerclage significantly prolongs gestation. However, unnecessary cerclage in women with a CL >2.5 cm may result in a higher risk of preterm labor and histologic chorioamnionitis although this study has a limitation originated from retrospective design.

Cervical length measurement between 11 and 13 + 6 weeks of pregnancy: Comparison of maternal and ultrasonographic characteristics between term and preterm deliveries.

OBJECTIVE: The aim of this study was to evaluate the maternal and ultrasonographic characteristics of pregnant women who underwent cervical length (CL) measurement by transvaginal ultrasound between 11 and 13 + 6 weeks of gestation and who delivered at term or preterm. METHODS: A retrospective cohort study was carried out between March 2013 and December 2018 by analyzing ultrasound data of singleton pregnant women who underwent CL measurement by transvaginal ultrasound during the first trimester scan. CL was compared between the two groups (full-term and preterm birth [PB]) using Student's t-test. RESULTS: A total of 5097 pregnant women were enrolled, of whom 5061 (99.3%) had term and 36 (0.7%) had PB < 34 weeks. CL measurements did not differ between the term and preterm groups (36.62 vs. 37.83 mm, p = 0.08). Maternal age showed a significant and linear association with CL (r = 0.034, p = 0.012) and CRL (r = 0.086, p < 0.001). Smoking status was associated with shorter CL (36.64 vs. 35.09 mm, p = 0.003). When we analyzed the CL of the pregnant women in the term and preterm groups, according to the gestational age cut-offs for prematurity (28, 30, 32, and 34 weeks), we found that there was no significant difference between the measurements in all groups (p > 0.05). CONCLUSION: We observed no significant differences between CL measurements between 11 and 13 + 6 weeks in pregnant women who had preterm and term deliveries. Gestational age and CRL showed a significant and linear association with CL measurement.

Screening for women at risk of spontaneous preterm birth, including cervical incompetence.

Preterm births remain one of the biggest challenges in obstetrics worldwide. With the advancement of neonatal care, more premature neonates survive with long term consequences. Therefore, preventing or delaying preterm births starting from the preconceptional or antenatal periods are important. Among the numerous screening strategies described, not one can fit into all. Nonetheless, approaches including identifying women with modifiable risk factors for preterm births, genitourinary infections and short cervical length are the most useful. In this article, the current evidence is summarized and the best strategies for common clinical scenerios including cervical incompetence, history of second trimester loss or early preterm births, incidental short cervix and multiple pregnancy are discussed.

Assessment of obstetric history and cervical length as risk factors for preterm birth / Evaluación de la história obstétrica y la longitud cervical como factores de riesgo para el parto prematuro

Introduction: Preterm birth, before 37 weeks of gestation, is the main determinant of neonatal morbidity and mortality and is associated with serious consequences,including compromised quality of life for the affected individual and physical, psychological, and economic costs. Objective: To evaluate the correlation of obstetric history, cervicovaginal infections, and cervical length with preterm birth. A prospective, blind cohort study evaluated 1,370 pregnant women from Ribeirão Preto between 20 and 25 weeks of gestation. Materials and methods: The correlation between obstetric history, cervical length, and gestational age at birth was obtained by calculating the relative risk of the different variables. Results: The distribution of pregnant women according to cervical length (CL) showed a predominance of women with a cervix longer than 2.5 cm (n = 1,308, 95.8%), followed by women with a cervix between 2 and 2.49 cm (n = 42, 3.1%) and < 2 cm (n = 15, 1.1%). Among the 1,370 pregnant women evaluated, 133 had spontaneous preterm birth (< 259 days); 14 (10.5%) preterm births occurred in women under 19 years of age, 105 (79%) in women between 19 and 35 years, and 14 (10.5%) in women older than 35 years. Microbiological analysis showed the growth of Mycoplasma hominis, Ureaplasma urealyticum, and other bacteria in 8, 17, and 16 women with preterm birth, respectively. Among the 133 women with spontaneous preterm birth, CL was < 2.5 cm in 15 women, < 2 cm in 3, < 1.5 cm in 3, and < 1 cm in 2. Conclusion: The identification of pregnant women at high risk for preterm delivery can reduce the incidence of preterm birth. Although no gold standard test exists for the prediction of preterm birth, this study confirms that the measurement of CL is a good individual predictor.

Introducción: El nacimiento pretérmino, antes de las 37 semanas de gestación, es el principal determinante de la morbimortalidad neonatal y se asocia a graves consecuencias,incluyendo el compromiso de la calidad de vida del individuo afectado y costes físicos, psicológicos y económicos. Objetivo: Evaluar la correlación de los antecedentes obstétricos, infecciones cervicovaginales y longitud cervical con el parto prematuro. Estudio de cohorte prospectivo, ciego, evaluando 1.370 gestantes de Ribeirão Preto entre 20 y 25 semanas de gestación. Material y métodos: La correlación entre los antecedentes obstétricos, la longitud cervical y la edad gestacional al nacer se obtuvo calculando el riesgo relativo de las diferentes variables. Resultados: La distribución de las gestantes según la longitud cervical (LC) mostró un predominio de mujeres con cuello uterino mayor de 2,5 cm (n = 1,308, 95.8%), seguidas de mujeres con cuello uterino entre 2 y 2,49 cm (n = 42, 3.1%) y menor de 2 cm (n = 15, 1.1%). De las 1,370 embarazadas evaluadas, 133 tuvieron un parto prematuro espontáneo (< 259 días); 14 (10.5%) partos prematuros se produjeron en mujeres menores de 19 años, 105 (79%) en mujeres de entre 19 y 35 años, y 14 (10.5%) en mujeres mayores de 35 años. Los análisis microbiológicos mostraron la proliferación de Mycoplasma hominis, Ureaplasma urealyticum y otras bacterias en 8, 17 y 16 mujeres con parto prematuro, respectivamente. Entre las 133 mujeres con parto prematuro espontáneo, la CL fue < 2.5 cm en 15 mujeres, < 2 cm en 3, < 1.5 cm en 3 y < 1 cm en 2. Conclusión: La identificación de las gestantes con alto riesgo de parto prematuro puede reducir la incidencia de parto prematuro. Aunque no existe una prueba de referencia para la predicción del parto prematuro, este estudio confirma que la medición de la longitud cervical es una buena predicción individual.