Prediction of Preterm Birth with the Uterocervical Angle in Singleton Pregnancies Treated with a Cervical Pessary.

BACKGROUND: Cervical pessaries are an established therapy option for patients at risk for spontaneous preterm birth (sPTB). The uterocervical angle (UCA) remains a promising sPTB predictor. However, its clinical significance has yet to be described in patients treated with a pessary. METHODS: This study analyzed data of patients treated with a pessary because of cervical shortening in singleton pregnancies. The patients were divided into 2 groups according to transvaginal ultrasound findings: the funneling group (n = 68) and the no-funneling group (n = 42). Moreover, we analyzed patients within these prespecified groups according to the UCA < 95° and ≥ 95°. RESULTS: Delivery occurred significantly earlier in patients treated with a pessary and with a high UCA ≥ 95°(p = 0.006). The median gestational age at delivery in patients treated with a pessary and with no funneling and a UCA < 95° vs. ≥ 95° were 39.00 and 36.14 weeks, respectively (p = 0.005). In cases with funneling and a UCA < 95° vs. ≥ 95° the mean gestational age at delivery was 38.14 and 38.07 weeks respectively (p=1,00). There was a significant negative linear correlation between UCA and the gestational age at delivery in all patients (p = 0.04), which was even profound in the group without funneling (p = 0.0002). However, we found no significant correlation between cervical length and gestational age at delivery in all patients (p = 0.42) as well as in the group without funneling (p = 0.28). CONCLUSION: In spite of pessary treatment, patients with UCA ≥ 95° presented with a higher risk of sPTB compared to patients with UCA < 95°. This suggests that the UCA seems to be a better predictor of sPTB than the cervical length in patients receiving pessary treatment.

Cervical pessary to prevent preterm birth and poor neonatal outcome: An integrity meta-analysis of randomized controlled trials focusing on adherence to the European Medical Device Regulation.

BACKGROUND: Findings from randomized trials (RCTs) on cervical pessary treatment to prevent spontaneous preterm birth are inconsistent. OBJECTIVES: Our hypothesis suggests that adhering to the European Medical Device Regulation (MDR) and following the instructions for use are essential prerequisites for successful therapy. Conversely, the non-adherence to these guidelines will probably contribute to its failure. SEARCH STRATEGY AND SELECTION CRITERIA: Based on validated criteria from integrity assessments we performed a systematic review identifying 14 RCTs evaluating the effect of cervical pessaries. DATA COLLECTION AND ANALYSIS: We analyzed the implications of 14 criteria each accounting for 0-2 points of a score reflecting the clinical evaluation plan (CEP) as proposed by the MDR to evaluate the risk-benefit ratio of medical devices. MAIN RESULTS: Seven RCTs in each singleton and twin pregnancies (5193 "cases") were included, detecting a high heterogeneity within control groups (I2 = 85% and 87%, respectively, P < 0.01). The CEP score varied from 11 to 26 points for all studies. The most common reasons for low scores and potential data compromise were poor recruitment rates, no (completed) power analysis, and no pre-registration, but mainly non-adherence to technical, biological, and clinical equivalence to the instructions for use as required by the MDR. All trials with score values greater than 20 had applied audit procedures. Within this group we found significantly reduced rates of spontaneous preterm birth at less than 34 weeks within the pessary group in singleton (odds ratio 0.28; 95% confidence interval 0.12-0.65) and twin pregnancies (odds ratio 0.30; 95% confidence interval 0.13-0.67). Similarly, there was a significant reduction in the composite poor neonatal outcome in singleton (odds ratio 0.25; 95% confidence interval 0.10-0.61) and twin pregnancies (odds ratio 0.54; 95% confidence interval 0.35-0.82) after a pessary as compared with controls. CONCLUSION: Non-audited RCTs and meta-analyses mixing studies of different clinical quality as pre-defined by a CEP and the MDR pose the risk for erroneous conclusions.

A novel aspiration technique to assess cervical remodelling in patients with or without cervical shortening: Sequence of first changes, definition of cut-off values and impact of cervical pessary, stratified for cervical length.

BACKGROUND: The therapeutic significance of the cervical pessary has been confirmed by several studies. However, the underlying mechanism by which pessaries reduce the risk of a preterm birth remains elusive. The aim of this study is to investigate the hypothesis whether the application of a cervical pessary may stabilize the ectocervical stiffness in order to achieve a cervical arrest. METHODS: This is a prospective, controlled, non-interventional, post-market, monocentric, longitudinal, cohort study in a tertiary maternity hospital to determine ectocervical stiffness and its changes measured before and after placement of a pessary in singleton pregnancies with cervical shortening in the mid trimester. In order to assess reference values for cervical stiffness, we measured also singleton pregnancies with normal cervical length in the same gestational week spectrum. The cervical stiffness measured with the Pregnolia System as the Cervical Stiffness Index (CSI, in mbar) shall be the primary endpoint, whilst patient delivery data (gestational age, mode of delivery and complications) will be the secondary endpoint. In this pilot study, up to 142 subjects will be enrolled to have a total of 120 subjects (estimated dropout rate of 15%) to complete the study; pessary cohort: 60 (up to 71 recruited), control group: 60 (up to 71 recruited). DISCUSSION: Our hypothesis is that patients with cervical shortening will present with lower CSI values and that pessary placement will be able to stabilize the CSI values through further prevention of cervical remodelling. The measurement of controls with normal cervical length shall serve as a reference.