The role of cervical pessary and progesterone therapy in the phenomenon of placenta previa migration

Are Cervical Pessaries Effective in Preventing Preterm Birth?

Preterm births are a significant concern, as they can have serious consequences for both infants and mothers. It is crucial to identify risk factors associated with preterm birth and to implement effective interventions, such as progesterone, cervical pessary, and cervical cerclage, to prevent it. This systematic review aims to evaluate the efficacy of cervical pessary in reducing spontaneous preterm delivery. However, cervical pessaries have limited research and conflicting findings when compared to other interventions for preventing preterm labor. Therefore, this review seeks to analyze various studies to evaluate their overall effectiveness and better understand their role in treating this vulnerable population. The literature search was conducted using PubMed between January and September 2023, and the systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The results of this review highlight the importance of continued research into mitigation strategies for preterm birth. There is some evidence that indicates that using cervical pessaries before 34 weeks can be effective. While some studies have reported positive outcomes when cervical pessaries are combined with other treatments like progesterone, there is no solid statistical evidence to support this claim. Furthermore, additional research is needed to comprehend the impact of singleton pregnancies and long-term outcomes for both mothers and infants.

Cervical pessary for preventing preterm birth in singleton pregnancies

BACKGROUND

Preterm birth (PTB), defined as birth prior to 37 weeks of gestation, occurs in ten percent of all pregnancies. PTB is responsible for more than half of neonatal and infant mortalities and morbidities. Because cervical insufficiency is a common cause of PTB, one possible preventive strategy involves insertion of a cervical pessary to support the cervix. Several published studies have compared the use of pessary with different management options and obtained questionable results. This highlights the need for an up-to-date systematic review of the evidence.

OBJECTIVES

To evaluate the benefits and harms of cervical pessary for preventing preterm birth in women with singleton pregnancies and risk factors for cervical insufficiency compared to no treatment, vaginal progesterone, cervical cerclage or bedrest.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform to 22 September 2021. We also searched the reference lists of included studies for additional records.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) comparing cervical pessary with no treatment, vaginal progesterone, cervical cerclage or bedrest for preventing PTB. We excluded quasi-randomised trials. Our primary outcome was delivery before 34 weeks' gestation. Our secondary outcomes were 1. delivery before 37 weeks' gestation, 2. maternal mortality, 3. maternal infection or inflammation, 4. preterm prelabour rupture of membranes, 5. harm to woman from the intervention, 6. maternal medications, 7. discontinuation of the intervention, 8. maternal satisfaction, 9. neonatal/paediatric care unit admission, 10. fetal/infant mortality, 11. neonatal sepsis, 12. gestational age at birth, 13. harm to offspring from the intervention 14. birthweight, 15. early neurodevelopmental morbidity, 15. late neurodevelopmental morbidity, 16. gastrointestinal morbidity and 17. respiratory morbidity.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and risk of bias, evaluated trustworthiness based on criteria developed by the Cochrane Pregnancy and Childbirth Review Group, extracted data, checked for accuracy and assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

We included eight RCTs (2983 participants). We included five RCTs (1830 women) in the comparison cervical pessary versus no treatment, three RCTs (1126 pregnant women) in the comparison cervical pessary versus vaginal progesterone, and one study (13 participants) in the comparison cervical pessary versus cervical cerclage. Overall, the certainty of evidence was low to moderate due to inconsistency (statistical heterogeneity), imprecision (few events and wide 95% confidence intervals (CIs) consistent with possible benefit and harm), and risk of performance and detection bias. Cervical pessary versus no treatment Cervical pessary compared with no treatment may reduce the risk of delivery before 34 weeks (risk ratio (RR) 0.72, 95% CI 0.33 to 1.55; 5 studies, 1830 women; low-certainty evidence) or before 37 weeks (RR 0.68, 95% CI 0.44 to 1.05; 5 studies, 1830 women; low-certainty evidence). However, these results should be viewed with caution because the 95% CIs cross the line of no effect. Cervical pessary compared with no treatment probably has little or no effect on the risk of maternal infection or inflammation (RR 1.04, 95% CI 0.87 to 1.26; 2 studies, 1032 women; moderate-certainty evidence). It is unclear if cervical pessary compared with no treatment has an effect on neonatal/paediatric care unit admission (RR 0.96, 95% CI 0.58 to 1.59; 3 studies, 1332 infants; low-certainty evidence) or fetal/neonatal mortality (RR 0.93, 95% CI 0.58 to 1.48; 5 studies, 1830 infants; low-certainty evidence) because the 95% CIs are compatible with a wide range of effects that encompass both appreciable benefit and harm. Cervical pessary versus vaginal progesterone Cervical pessary may reduce the risk of delivery before 34 weeks (RR 0.72, 95% CI 0.52 to 1.02; 3 studies, 1126 women; moderate-certainty evidence) or before 37 weeks (RR 0.89, 95% CI 0.73 to 1.09; 3 studies, 1126 women; moderate-certainty evidence), but we are uncertain of the results because the 95% CI crosses the line of no effect. The intervention probably has little or no effect on maternal infection or inflammation (RR 0.95, 95% CI 0.81 to 1.12; 2 studies, 265 women; moderate-certainty evidence). It is unclear if cervical pessary compared with vaginal progesterone has an effect on the risk of neonatal/paediatric care unit admission (RR 0.98, 95% CI 0.49 to 1.98; low-certainty evidence) or fetal/neonatal mortality (RR 1.97, 95% CI 0.50 to 7.70; 2 studies; 265 infants; low-certainty evidence) because the 95% CIs are compatible with a wide range of effects that encompass both appreciable benefit and harm. Cervical pessary versus cervical cerclage Only one very small study of 13 pregnant women contributed data to this comparison; the results were unclear.

AUTHORS' CONCLUSIONS

In women with a singleton pregnancy, cervical pessary compared with no treatment or vaginal progesterone may reduce the risk of delivery before 34 weeks or 37 weeks, although these results should be viewed with caution due to uncertainty around the effect estimates. There is insufficient evidence with regard to the effect of cervical pessary compared with cervical cerclage on PTB. Due to low certainty-evidence in many of the prespecified outcomes and non-reporting of several other outcomes of interest for this review, there is a need for further robust RCTs that use standardised terminology for maternal and offspring outcomes. Future trials should take place in a range of settings to improve generalisability of the evidence. Further research should concentrate on comparisons of cervical pessary versus cervical cerclage and bed rest. Investigation of different phenotypes of PTB may be relevant.

Does a cervical pessary reduce the rate of preterm birth in women with a short cervix?

OBJECTIVES

To evaluate neonatal outcomes after the use of a cervical pessary in Japanese women with short cervical length (CL) less than 25 mm.

METHODS

This multicenter study involved women with singleton pregnancies between 20 and 29+6 gestational weeks and a CL of less than 25 mm. The primary outcome was preterm birth (PTB) before 34 weeks of gestation. This study was registered in the Japan Registry of Clinical Trials (JRCT: jRCTs042180102).

RESULTS

Two hundred pregnant women were enrolled; 114 in the pessary group and 86 in the expectant management group as controls. In the pessary group, all 114 neonates were investigated for perinatal outcomes, and 112 pregnant women were investigated for primary, and secondary outcomes. In the control group, 86 pregnant women were investigated for primary and secondary outcomes and 86 neonates were investigated for neonatal outcomes. There were no significant differences in PTB in ≤34, ≤37, and ≤28 weeks of gestation or in preterm rupture of membranes (PROM) ≤34 weeks between the groups. The gestational weeks at birth and birth weight were significantly higher in the pessary group. Regression analysis demonstrated that the CL decreased without a pessary, whereas the shortening rate was suppressed during the intervention. No significant differences were observed in adverse neonatal outcomes, chorioamnionitis, or preterm PROM.

CONCLUSIONS

The cervical pessary effectively reduced CL shortening during pregnancy resulting in an average increased gestational age, however, did not reduced the rates of preterm birth.

Risk of preterm birth for placenta previa or low-lying placenta and possible preventive interventions: A systematic review and meta-analysis

Objective

To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive interventions.

Search and methods

MEDLINE, EMBASE, CENTRAL, Web of Science, WHO-ICTRP and clinicaltrials.gov were searched until December 2021. Randomized controlled trials, cohort studies and case-control studies assessing preterm birth in women with placenta previa or low-lying placenta with a placental edge within 2 cm of the internal os in the second or third trimester were eligible for inclusion. Pooled proportions and odds ratios for the risk of preterm birth before 37, 34, 32 and 28 weeks of gestation were calculated. Additionally, the results of the evaluation of preventive interventions for preterm birth in these women are described.

Results

In total, 34 studies were included, 24 reporting on preterm birth and 9 on preventive interventions. The pooled proportions were 46% (95% CI [39 - 53%]), 17% (95% CI [11 - 25%]), 10% (95% CI [7 - 13%]) and 2% (95% CI [1 - 3%]), regarding preterm birth <37, <34, <32 and <28 weeks in women with placenta previa. For low-lying placentas the risk of preterm birth was 30% (95% CI [19 - 43%]) and 1% (95% CI [0 - 6%]) before 37 and 34 weeks, respectively. Women with a placenta previa were more likely to have a preterm birth compared to women with a low-lying placenta or women without a placenta previa for all gestational ages. The studies about preventive interventions all showed potential prolongation of pregnancy with the use of intramuscular progesterone, intramuscular progesterone + cerclage or pessary.

Conclusions

Both women with a placenta previa and a low-lying placenta have an increased risk of preterm birth. This increased risk is consistent across all severities of preterm birth between 28-37 weeks of gestation. Women with placenta previa have a higher risk of preterm birth than women with a low-lying placenta have. Cervical cerclage, pessary and intramuscular progesterone all might have benefit for both women with placenta previa and low-lying placenta, but data in this population are lacking and inconsistent, so that solid conclusions about their effectiveness cannot be drawn.

Systematic review registration

PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42019123675.

Prevention of Preterm Birth by Cervical Pessary Combined with Vaginal Progesterone: a Systematic Review and Meta-analysis with Trial Sequential Analysis

This study was to assess the effectiveness of cervical pessary combined with vaginal progesterone for the prevention of preterm birth (PTB). Ten studies about singleton [five randomized controlled trials (RCTs), vs vaginal progesterone; four cohorts, vs vaginal progesterone; two cohorts, vs cervical cerclage + vaginal progesterone] and two cohort studies about multiple pregnancies (vs vaginal progesterone) were included after searching electronic databases. For singleton pregnancies, the meta-analysis of three non-RCTs [relative risk (RR) = 0.41, p = 0.001] or total trials in non-Asian country (RR = 0.56, p = 0.03) revealed that compared with vaginal progesterone alone, cervical pessary + vaginal progesterone treatment had significant effectiveness on preventing PTB < 34 weeks, but not for five RCTs; meta-analysis of two trials showed that cervical pessary + vaginal progesterone had no significant prevention effects of PTB compared with cervical cerclage + vaginal progesterone. For multiple pregnancies, meta-analysis of two trials showed that compared with vaginal progesterone, cervical pessary + vaginal progesterone treatment increased neonatal birth weight (standardized mean difference = 0.50, p = 0.01). Trial sequential analysis implied additional studies were required. Four studies vs other controls (pessary, three-combined, tocolysis, conservative or no treatment; one study, each) were selected for systematic review. In conclusion, cervical pessary combined with vaginal progesterone may be safe and effective to prevent PTB in singleton pregnancies and increase neonatal birth weight in the multiple pregnancies compared with vaginal progesterone alone.

Is the Arabin Pessary really useful in preventing preterm birth? A review of literature

The aim of this review is to describe the state of the art in the use of Arabin Pessary for the prevention of spontaneous preterm birth (SPTB). We conducted a review of the literature in order to collect relevant studies concerning the efficacy of Arabin Pessary in preventing preterm birth, also considering it in addition or in comparison with other methods such as cervical cerclage or vaginal progesterone and in both singleton and twin pregnancy. Despite the large number of studies available there is not a clear consensus about the superiority of one of this methods over the others. In addition to this, although Arabin Pessary is widely used in clinical practice, no guidelines for management and use of cervical pessary during pregnancy have been assessed.

Analysis of risk factors and predictors of pregnancy loss and strategies for the management of cervical insufficiency in pregnant women at a high risk of preterm birth

AIM

To identify risk factors and predictors of pregnancy loss and to compare the efficacy of Arabin's pessary with cervical cerclage in women at a high risk of pregnancy loss.

MATERIALS AND METHODS

This was a two-center retrospective case-control study that included 240 women at a high risk of preterm delivery. Group I (n = 161) included women who underwent insertion of the Arabin's pessary between 14 and 24 weeks of pregnancy. Group II (n = 79) included women who had undergone circular cervical cerclage during the current pregnancy. All women included in the study received micronized vaginal progesterone at the dose of 200 mg/day until and including 34 weeks of gestation.

RESULTS

Threatened pregnancy loss defined as spotting or vaginal bleeding in the first trimester was diagnosed in 29.8% (48/161) of patients in Group I versus 37.9% in Group II (p = .448). Postpartum bleeding occurred in 8.1% (13/161) in women in Group I versus 22.8% in Group II (χ² = 6.500; p = .011). Our study showed that cervical cerclage was most suitable for patients with history of obstetric complications, cervical length <15 mm, and large isthmic uterine fibroids. The use of the Arabin's pessary reduced the rate of preterm births by 1.7-fold. A cluster analysis demonstrated that predictors of preterm birth in women with a high risk of pregnancy loss included: threatened pregnancy loss associated with chorionic/placental abruption, cervical incompetence, uterine fibroid growth to a large size, history of multiple spontaneous pregnancy losses, cervical tears during past labor, and gestational diabetes diagnosed for the first time during the current pregnancy.

CONCLUSIONS

Women with a high risk of pregnancy loss treated with Arabin's pessary or cerclage plus vaginal progesterone had a term delivery rate of 70.4% (169/240). The combined strategy of pregnancy management allowed to markedly reduce the number of preterm births.

Managing female pelvic floor disorders: a medical device review and appraisal

Pelvic floor disorders (PFDs) will affect most women during their lifetime. Sequelae such as pelvic organ prolapse, stress urinary incontinence, chronic pain and dyspareunia significantly impact overall quality of life. Interventions to manage or eliminate symptoms from PFDs aim to restore support of the pelvic floor. Pessaries have been used to mechanically counteract PFDs for thousands of years, but do not offer a cure. By contrast, surgically implanted grafts or mesh offer patients a more permanent resolution but have been in wide use within the pelvis for less than 30 years. In this perspective review, we provide an overview of the main theories underpinning PFD pathogenesis and the animal models used to investigate it. We highlight the clinical outcomes of mesh and grafts before exploring studies performed to elucidate tissue level effects and bioengineering considerations. Considering recent turmoil surrounding transvaginal mesh, the role of pessaries, an impermanent method, is examined as a means to address patients with PFDs.

Cervical Pessary versus Expectant Management for the Prevention of Delivery Prior to 36 Weeks in Women with Placenta Previa: A Randomized Controlled Trial

Objective  This multicenter randomized controlled trial compared cervical pessary (CP) versus expectant management (EM) in women with placenta previa between 22.0 and 32.0 in prolonging gestation until ≥ 36.0 weeks' gestation. Study Design  This study took place from November 2016 to June 2018. Women were randomized to receive either the Bioteque CP or EM. The pessary was removed at ≥ 36.0 weeks unless indicated. The primary outcome was gestational age (GA) at delivery, with secondary outcomes including need for transfusion, number and duration of antepartum admissions, type of delivery, and neonatal outcomes. A total of 140 patients were needed to show a 3-week prolongation of pregnancy in the pessary group; however, the trial was stopped early due to budgetary issues. Results  Of the 33 eligible women, 17 were enrolled. Although not statistically significant, the mean GA at delivery in the CP group was greater than women in the EM group (36.5 ± 1.23 vs. 36.0 ± 2.0; p  = 0.1673). The number and duration of antepartum admissions was greater in the EM group (2.7 ± 0.58 vs. 16.0 ± 22.76 days; p  = 0.1264) as well. Conclusion  Although the study was underpowered to determine the primary outcome, safety and feasibility of CP in pregnancies complicated with previa were demonstrated.