Antenatal cervical length measurement as a predictor of successful vaginal birth

The effect of preinduction cervical length measurement with three different ultrasonographic methods on predicting delivery time

AIM

This study aimed to evaluate the effect of preinduction cervical length (CL) measurement by transvaginal (TV), transperineal (TP), and transabdominal (TA) ultrasonography (USG) on the time of delivery and to compare these three sonographic methods in terms of superiority over one another.

METHODS

This study included TV, TP, and TA CL measurements in pregnant women who were planned to undergo induction of labor at 37 weeks' gestation or later. The correlations between the said three methods and BISHOP scores were evaluated. These three methods were compared in terms of superiority in predicting the time of delivery.

RESULTS

Pregnant women at 37-42 weeks' gestation undergoing labor induction were included, and all three methods were used for CL measurements. Three methods were correlated with each other (p < 0.001) and with BISHOP scores (p < 0.001).

CONCLUSION

The correlation between all three methods and BISHOP scores indicates that TP and TA USG can be used instead of TV USG. On the other hand, while TA USG did not give a clear result in the accurate estimation of vaginal delivery time, TP, and TV USG gave both accurate and close results. When all these data are evaluated, it is concluded that TPU can be used safely instead of TVU, especially in patients receiving induction.

Pre-induction cervical assessment using transvaginal ultrasound versus Bishops cervical scoring as predictors of successful induction of labour in term pregnancies: A hospital-based comparative clinical trial

Objective

To evaluate the association between transvaginal ultrasound scan of cervix and Bishop’s score in predicting successful induction of labour, cut-off points and patients’ tolerability and acceptance for both procedures.

Design

A comparative clinical trial.

Setting

A tertiary hospital in Selangor, Malaysia.

Participants

294 women planned for elective induction of labour for various indications were included. All women had transvaginal ultrasound to assess the cervical length and digital vaginal examination to assess the Bishop cervical scoring by separate investigators before induction of labour.

Primary outcome measure

To evaluate the association of the cervical length by transvaginal ultrasound scan and Bishop score in predicting successful induction of labour.

Secondary outcome measure

Variables associated with successful induction of labour and patients’ tolerability and acceptance for transvaginal ultrasound scan of cervix.

Results

There was no statistically significant difference among the vaginal and Caesarean delivery groups in terms of mean maternal age, height, weight, body mass index, ethnicity and gestational age at induction. Vaginal delivery occurred in 207 women (70.4%) and 87 women (29.6%) delivered via Caesarean section. There was a high degree of correlation between the cervical length and Bishop score (r-value 0.745; p <0.001). Sonographic assessment of cervical length demonstrated a comparable accuracy in comparison to Bishop score. Analysis using ROC curves noted an optimal cut-off value of ≤27mm for cervical length and Bishop score of ≥ 4, with a sensitivity of 69.1% vs 67%, specificity 60.9% vs 55%, and area under the curves (AUCs) of 0.672 and 0.643 respectively (p <0.001). Multivariate logistic regression analysis demonstrated that parity (OR 2.70), cervical length (OR 0.925), Bishop score (OR 1.272) and presence of funnelling (OR 3.292) were highly significant as independent predictors of success labour induction. Women also expressed significantly less discomfort with transvaginal ultrasound compared with digital vaginal examination.

Conclusion

Sonographic assessment of cervical measurement predicts the success of induction of labour with similar diagnostic accuracy with conventional Bishop score.

The Value of Posterior Cervical Angle as a Predictor of Vaginal Delivery: A Preliminary Study

Accurate prediction of failure to progress and rapid decision making regarding the mode of delivery can improve pregnancy outcomes. We examined the value of sonographic cervical markers in the prediction of successful vaginal delivery beyond 34 weeks of gestation. A retrospective chart review was carried out. Medical information of singleton gestations delivered at a single center from 1 July 2019 to 30 August 2020 was collected. Transvaginal sonographic records of cervical length, anterior and posterior cervical angles, and cervical dilatation were obtained and re-measured. The value of these markers and clinical characteristics of mother and baby on vaginal delivery were investigated and compared to women who underwent cesarean section. A total of 90 women met the inclusion criteria. The rate of vaginal delivery was 75.6%. There were no differences found in terms of maternal age, rate of abortion, induction of labor, premature rupture of membranes, preterm labor, hypertension, diabetes, cervical length, and neonatal sex and weight. The prediction of vaginal delivery was provided by parity, maternal body mass index, and posterior cervical angle. The area under the receiver operating characteristic curve for prediction of vaginal delivery was 0.667 (95% CI 0.581–0.864, p = 0.017) for the posterior cervical angle, with a cutoff of 96.5°. Regression analysis revealed a posterior cervical angle ≥96.5° in the prediction of vaginal delivery (adjusted odds ratio: 6.24; 95% confidence interval: 1.925–20.230, p = 0.002). Posterior cervical angle ≥96.5° is associated with successful vaginal delivery. It is simple and easy to measure and can be useful in determining the mode of delivery.

Transvaginal ultrasound cervical length for prediction of spontaneous labor at term: A protocol for systematic review and meta-analysis

PURPOSE

To evaluate the predictive accuracy of transvaginal ultrasound (TVU) cervical length (CL) for spontaneous onset of labor in singleton gestation enrolled at term by a meta-analysis.

MATERIALS AND METHODS

This protocol established in this study has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Web of Science, PubMed, EMBASE, and the Cochrane Library were searched for all clinical trials assessing the accuracy of TVU CL in prediction of spontaneous onset of labor in singleton gestations with vertex presentation who were enrolled at term until August 15, 2020. We will use a combination of Medical Subject Heading and free-text terms with various synonyms to search based on the eligibility criteria. Two investigators independently reviewed the included studies and extracted relevant data. The 95% confidence intervals (CIs) of was used as effect estimate. I-square (I2) test, substantial heterogeneity, sensitivity analysis, and publication bias assessment will be performed accordingly. Stata 15.0 and Review Manger 5.3 are used for meta-analysis and systematic review.

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSION

The results of this review will be widely disseminated through peer-reviewed publications and conference presentations. This evidence may also assess the accuracy of TVU CL in prediction of spontaneous onset of labor in singleton gestations with vertex presentation.

REGISTRATION NUMBER

INPLASY202080065.