Beyond Cervical Length: Association between Postcerclage Transvaginal Ultrasound Parameters and Preterm Birth

Concurrent progestogen and cerclage to reduce preterm birth: a multicenter international retrospective cohort

BACKGROUND

Both progestogens and cerclage are individually effective in preterm birth prevention in high risk pregnancies. However, national and international guidelines cite a lack of data available to comment on the potential benefit of concurrent progestogen therapy after cerclage has been placed. Studies to date have been small with mixed results regarding benefit of concurrent progestogen with cerclage leaving uncertainty regarding best clinical practice.

OBJECTIVE

This study aimed to evaluate whether cerclage with progestogen therapy was superior to cerclage alone in the prevention of spontaneous preterm birth in singleton pregnancies.

METHODS

This is an international retrospective cohort study of singleton pregnancies, without major anomaly or aneuploidy, and with cerclage placed at 10 different institutions in the United States and Colombia from June 2016 to June 2020. Exclusion criteria were lack of documentation regarding whether progestogen was prescribed, unavailable delivery outcome, and pregnancy termination (spontaneous or induced) before 16 weeks' gestation. The exposure of interest was progestogen use with cerclage placement, which included those who continued to use progestogen or who started progestogen after cerclage. The comparison group consisted of those without progestogen use after cerclage placement, which included those who had no progestogen use during the entire pregnancy or who initiated progestogen and then stopped it after cerclage placement. Progestogen type, cerclage indication, maternal baseline characteristics, and maternal/neonatal outcomes were collected. The primary outcome was spontaneous preterm birth at <37 weeks. The secondary outcomes were spontaneous preterm birth at <34 weeks, gestational age at delivery, and a composite neonatal outcome including ≥1 of the following: perinatal mortality, confirmed sepsis, grade III or IV intraventricular hemorrhage, retinopathy of prematurity, respiratory distress syndrome, and bronchopulmonary dysplasia. There were planned subgroup analyses by cerclage indication, progestogen type (vaginal progesterone vs 17-hydroxyprogesterone caproate), preterm birth history, and site. Continuous variables were compared in adjusted analyses with analysis of covariance, and categorical variables were compared with multivariable logistic regression, adjusting for potential confounders with adjusted odds ratio. A Cox regression survival curve was generated to compare latency to spontaneous delivery, censored after 37 weeks.

RESULTS

During the study period, a total of 699 singletons met the inclusion criteria: 561 in the progestogen with cerclage group and 138 with cerclage alone. Baseline characteristics were similar, except the higher likelihood of previous spontaneous preterm birth in the progestogen group (61% vs 41%; P<.001). Within the progestogen group, 52% were on 17-hydroxyprogesterone caproate weekly, 44% on vaginal progesterone daily, and 3% on oral progesterone daily. Progestogen with cerclage was associated with a significantly lower frequency of spontaneous preterm birth <37 weeks (31% vs 39%; adjusted odds ratio, 0.59 [0.39-0.89]; P=.01) and <34 weeks (19% vs 27%; adjusted odds ratio, 0.55 [0.35-0.87]; P=.01), increased latency to spontaneous delivery (hazard ratio for spontaneous preterm birth <37 weeks, 0.66 [0.49-0.90]; P=.009), and lower frequency of perinatal death (7% vs 16%; adjusted odds ratio, 0.37 [0.20-0.67]; P=.001). In planned subgroup analyses, association with reduced odds of preterm birth <37 weeks persisted in those on vaginal progesterone, those without a previous preterm birth, those with ultrasound- or examination-indicated cerclage, those who started progestogen therapy before cerclage, and in sites restricted to the United States.

CONCLUSION

Use of progestogen with cerclage was associated with reduced rates of spontaneous preterm birth and early spontaneous preterm birth compared with cerclage alone. Although this study was not sufficiently powered for subgroup analysis, the strength of evidence for benefit appeared greatest for those with ultrasound- or examination-indicated cerclage, and with vaginal progesterone. El resumen está disponible en Español al final del artículo.

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.

Value of post-cerclage transvaginal ultrasound in predicting preterm birth at <28 weeks in twin pregnancy with ultrasound-indicated cerclage

OBJECTIVE

To evaluate the value of transvaginal ultrasound parameters before and after cerclage in twins in predicting spontaneous preterm birth (sPTB) before 28+0 weeks.

METHODS

We retrospectively studied the medical records of twin-pregnant women who underwent ultrasound-indicated cerclage between January 2016 and February 2022 at our hospital. Recorded transvaginal ultrasound images before and after cerclage were reassessed for cervical length (CL), uterocervical angle (UCA), funneling, and sludge. Multivariate logistic and Cox regression analyses were performed to identify the independent risk factors associated with sPTB before 28 weeks.

RESULTS

A total of 69 women were included. Among them, 17 women (24.64%) delivered before 28 weeks of age. Regression analysis revealed a significant association of post-cerclage CL, UCA, white blood cell (WBC) count, and gestational age (GA) at cerclage with sPTB before 28 weeks. The area under the curve of these predictors was 0.938 (95% confidence interval, 0.882-0.994; p < .001), with a sensitivity of 88.2%, specificity of 92.3%, positive predictive value of 78.9%, and negative predictive value of 96.0%. Cox analysis showed that post-cerclage UCA was an independent risk factor affecting the cerclage-to-delivery interval (hazard ratios, 1.026; 95% confidence interval (CI), 1.004-1.048; p = .019).

CONCLUSIONS

The combination of post-cerclage CL, UCA, WBC count, and GA at cerclage showed good performance in predicting sPTB at <28 weeks in twin pregnancy. Post-cerclage UCA is also associated with pregnancy latency. We found that post-cerclage cervical ultrasound may be useful to predict preterm birth before 28 weeks in twins who undergo ultrasound-indicated cerclage.

Measurement of the uterocervical angle for the prediction of preterm birth in symptomatic women

Purpose

To examine if the uterocervical angle (UCA) can be used to predict preterm delivery in women with painful and regular uterine contractions and a cervical length of 25 mm or less.

Methods

Retrospective study at the perinatal unit of the University Hospital of Tuebingen, Germany. Women with singleton gestation and preterm contractions between 24 + 0 and 33 + 6 weeks’ gestation were included. For the UCA measurement, a line is placed from the internal os to the external os irrespective of whether the cervix is straight or curved. A second line is drawn to delineate the lower uterine segment. The angle between the two lines is the UCA measurement. The measurements were taken on stored images from our database.

Results

The study consisted of 213 singleton pregnancies. At the time of UCA measurement, median maternal and gestational age was 31.4 years and 29.7 weeks’ gestation. Median gestational age at delivery was 35.3 weeks and the corresponding birth weight 2480 g, respectively. The UCA measurement in women who delivered within 2 days, between 3–7 days and after 7 days was not helpful to distinguish between these three groups [median UCA measurements: 108.5°, 108.0° and 107.3° (Kruskal–Wallis test p = 0.576)]. Uni- and multivariate logistic multiple regression analysis demonstrated that the delivery within 2 days was only dependent on the gestational age and the cervical length at the time of presentation.

Conclusion

The measurement of UCA is not useful in predicting preterm birth in the subsequent 7 days after an episode of preterm contractions.

The association between sonographic cervical length components and preterm birth in women with ultrasound- or exam-indicated cerclage

OBJECTIVE

To evaluate which parameters of a sonographic cervical length measurement are associated with preterm birth in women with ultrasound- or exam-indicated cerclage.

METHODS

This was a retrospective cohort study of women with singleton pregnancies who underwent ultrasound- or exam-indicated Shirodkar cerclage by a single maternal-fetal medicine practice between 2011 and 2019. All patients underwent sonographic cervical length measurement 2-3 weeks after cerclage placement, and then every 2-4 weeks up to 32 weeks. The images from the first and second post-cerclage cervical lengths were reviewed. Total cervical length, upper cervical length (from the internal cervical os to the cerclage), and lower cervical length (from the cerclage to the external os) were measured. The primary outcome for this study was gestational age at delivery.

RESULTS

A total of 114 women with cerclage were included (85 (74.6%) ultrasound-indicated and 29 (25.4%) exam-indicated). The first and second total cervical lengths correlated with gestational age at delivery (r = 0.26, p=.005; r = 0.33, p<.001, respectively), and the change from first to second was inversely correlated with gestational age at delivery (r = -0.20, p=.032). The first and second upper cervical lengths also correlated with gestational age at delivery (r = 0.22, p = .019; r = 0.33, p<.001, respectively), and the change from first to second upper cervical length was inversely correlated with gestational age at delivery (r= -0.20, r = 0.029). Neither the first nor the second lower cervical lengths were significantly associated with gestational age at delivery. On regression analysis, total cervical length and upper cervical length were not independently associated with gestational age at delivery (p = .108 and p=.806, respectively, for the first scan; p = .153 and p=.166, respectively, for the second scan).

CONCLUSIONS

Postcerclage total cervical length and upper cervical length are both associated with gestational age at delivery and risk of preterm birth, but not independently. After ultrasound- or exam-indicated cerclage, sonographic monitoring of either the total cervical length or the upper cervical length might be predictive of gestational age at delivery and the risk of preterm birth.

Pessary use in patients diagnosed with short cervix and cervical insufficiency

OBJECTIVE

The aim was to evaluate the effectiveness of Arabin pessary use in patients with cervical insufficiency or short cervix before the 24th week of gestation and the impact of cervical examination findings prior to pessary application on the outcome in terms of the gestational week.

MATERIALS AND METHODS

In our study, among the pregnancies between the 12th and 24th gestational weeks, 60 pregnant women with a preterm delivery history and/or cervical length less than 25 mm were included. Among these 60 patients, 43 of them had a short cervix, 17 of them had cervical insufficiency. Routine medical and obstetric history was obtained. In the vaginal examination, the cervix was evaluated in terms of patency, dilatation, and position. Cervical length, presence of debris, and funneling were evaluated by transvaginal ultrasound. After receiving patients' approval a cervical pessary was applied to patients. Pessaries of pregnant women with 37 weeks of gestation were removed. Before reaching the 37th gestation week, pessaries were withdrawn in patients who had ongoing vaginal bleeding, premature rupture of membranes, and preterm contractions unresponsive to tocolytic treatment.

RESULTS

Thirty-one pregnant women (51.7%) out of 60 pregnant women who underwent pessary, delivered at 37 weeks and below. Delivery rates in the short cervical measurement group and cervical insufficiency group at ≤28 weeks, ≤34 weeks and ≤37 weeks were respectively (n = 21) 34.8% vs 36.3% (p = 0.976), (n = 29) 41.8% vs 64.7% (p = 0.111), (n = 31) 44.2% vs 70.6% (p = 0.888). The presence of cervical funneling before pessary application shows a statistically significant difference in terms of patient's giving birth before or after 28 weeks (p = 0.033). In patients with cervical funneling, there was a significant increase in a birth before 28 weeks. Depending on whether or not patients applying with pain need for tocolysis, it shows the statistically meaningful difference in terms of the patients giving birth before or after 34 weeks (p = 0.001) (OR 7, 61, 95% GA 2.4-24.6). In the group without the need for tocolysis, there is a meaningful increase in birth after 34 weeks.

CONCLUSIONS

Our findings showed that, alongside the defined cervical risk factors, cervical funneling and the need for tocolysis are remarkable prognostic variables in pessary application.

Presence of amniotic fluid sludge and pregnancy outcomes: A systematic review

INTRODUCTION

Several studies acknowledge that the presence of amniotic fluid sludge (AFS) is an independent predictive factor for preterm birth. In the present systematic review, we summarize research that focuses on the comparison of pregnancy outcomes among women with and without AFS.

MATERIAL AND METHODS

Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases were systematically searched from inception. Both observational and randomized controlled studies were considered eligible provided that they reported data on pregnancy outcomes among women with and without AFS. Outcomes were not meta-analyzed because of the high heterogeneity in terms of selected population and outcome reporting.

RESULTS

Seventeen studies of 2432 women were included in this review. Six studies evaluated women at high risk for preterm birth. Pregnancies complicated by AFS had a lower gestational age at delivery and increased incidence of preterm delivery at <37 weeks. Neonatal death rates and admission to the Neonatal Intensive Care Unit were also increased. Evidence in low-risk women, those with signs of preterm labor, in those carrying twins, and in women with cervical cerclage or Arabin pessary was extremely limited.

CONCLUSIONS

Women with AFS seem to deliver at an earlier gestational age, and preterm birth rates are also increased. Limited data seem to point to neonatal morbidity and mortality being increased. However, the presence of a direct association should not be assumed because the evidence is not adjusted for the presence of confounders.