Cervical pessary to prevent preterm birth in asymptomatic high-risk women: a systematic review and meta-analysis

Pessary or cerclage (PC study) to prevent recurrent preterm birth: a non-inferiority, randomised controlled trial

Background

Previous spontaneous preterm birth (sPTB) is a strong risk indicator for recurrent preterm birth (PTB). Cervical cerclage is an accepted intervention to prevent recurrent PTB in high risk patients. Cervical pessary might be a less invasive alternative. The objective of this study is to determine whether a cervical pessary is non-inferior to cerclage in the prevention of recurrent PTB.

Methods

We performed an international, open-label, non-inferiority, randomised controlled trial in 21 hospitals between March 2014 and December 2022. We included singleton pregnancies with an indication for cerclage based on either multiple previous sPTBs <34 weeks or with a previous sPTB <34 weeks and an asymptomatic mid-trimester short cervix (≤25 mm). Randomisation was 1:1, stratified by centre and indication, to cervical pessary or vaginal cerclage. Primary outcome was PTB <32 weeks. Secondary outcomes included (s)PTB rates, obstetric, and maternal outcomes and a composite of adverse perinatal outcomes including perinatal mortality and severe neonatal morbidity. Analysis was by intention-to-treat. Treatment effect was expressed as relative risk (RR), absolute risk difference (aRD) and 95% confidence intervals (CI). Sample size was calculated at 400 participants with a non-inferiority margin for pessary of 10%, meaning that non-inferiority is proven if the upper limit of the CI of the risk difference is <10%. Trial registration at ICTRP: NL-OMON26958.

Findings

We randomised 261 participants to pessary (n = 133) or cerclage (n = 128). After the third interim analysis (n = 228 participants), recruitment was halted due to safety concerns and the apparent challenge in establishing non-inferiority of pessary treatment. PTB <32 weeks occurred in 44/130 cases after pessary vs 30/125 cases after cerclage (33.8% vs 24.0% aRR 1.4, 95% CI 0.95-2.1, p = 0.09, aRD 9.8% 95% CI -1.2 to 20.9). The composite of adverse perinatal outcomes occurred in 42 cases after pessary compared to 29 cases in cerclage (32.2% vs 23.2%; RR 1.4 95% CI 0.93-2.1 p = 0.1) and consisted mainly of perinatal death (22.3% vs 14.4% RR 1.5 95% CI 0.9-2.6 p = 0.1).

Interpretation

Non-inferiority of cervical pessary compared to cerclage in preventing recurrent PTB <32 weeks was not proven. Cerclage is the recommended treatment.

Funding

ZonMw (#837002406), a Dutch Organisation for Health Research and Development.

Cervical cerclage vs cervical pessary in women with cervical insufficiency: A multicentric, open-label, randomised, controlled pilot trial [the CEPEIC trial]

Objective

Cervical insufficiency accounts for 8 % of preterm births. Pessary and cerclage are considered preventive approaches for preterm birth. These interventions were compared in terms of reducing the prematurity rate in women with previous preterm birth, due to cervical insufficiency or due to having a short cervix in their current pregnancy.

Methods

This was a prospective, multicentric, open-label, randomised, pilot, controlled trial. Participants were women with singleton pregnancies who had previous preterm birth caused by cervical insufficiency or previous preterm birth and a short cervix [≤ 25 mm] in their current pregnancy. Women were randomised [1:1] to either cerclage or pessary. The primary outcome was to assess the feasibility of a trial on cervical pessary vs. cerclage to prevent preterm birth before 34 weeks in women with cervical insufficiency. As a secondary outcome, we studied the morbidity rate of the pessary versus the cerclage in women with cervical insufficiency and assessed the financial impact of using both devices in these women. The sample size was calculated based on the estimated population that we could potentially recruit: 60 women, 30 for each group, to ascertain whether the rate of preterm birth < 34 weeks of gestation may be reduced from 34 % to at least 27 % in the pessary group, as in the results obtained with the cerclage.

Results

No significant differences in preterm birth < 34 weeks of gestation were observed in our study, although it was underpowered to detect these differences [the relative risk [RR] of PB < 34 weeks of gestation was 0.8 [95 % CI: 0.31-2.09, p = 0.888]. The rates of obstetric and perinatal complications were similar for both devices [15 cases in both groups, 50 % of cases [RR; 0.6-1.68; p = 1]. Cervical pessary had fewer secondary effects than the cerclage [less bleeding at insertion in the pessary group compared with cerclage, 1 case vs 14 cases, p < 0.001; less pain at removal in the pessary group compared with cerclage, 14 vs 22 cases. p = 0.042 and less bleeding, 2 cases vs. 10 cases, p = 0.027].

Conclusions

Pessary does not seem less effective than cerclage, although these findings need to be confirmed in a larger randomised controlled trial. Pessary had fewer secondary effects than cerclage both at insertion and removal.

Sinopsis

Cervical pessary does not seem to be less effective than cerclage. Cervical pessary had fewer secondary effects than cerclage.

Rate of preterm delivery and latency period in asymptomatic patients undergoing cerclage for very short cervix ≤10.0 mm

BACKGROUND

In asymptomatic women with cervical length ≤10 mm, vaginal progesterone has a limited effect in reducing the rate of preterm delivery.

OBJECTIVE

This study aimed to estimate the rate of preterm delivery and mean latency period to delivery in asymptomatic women with no history of preterm delivery and a cervical length of ≤10.0 mm undergoing or not undergoing cerclage and who were not treated with vaginal progesterone.

STUDY DESIGN

This was a retrospective analysis of asymptomatic patients with singleton pregnancies and no history of preterm delivery with an incidental finding of a cervical length of ≤10.0 mm measured by transvaginal ultrasound during midtrimester scan. Of note, 56 patients (63.6%) underwent cerclage placement and 32 patients (36.4%) did not, none of them received vaginal progesterone. Patients with evidence of advanced dilation, prolapsing membranes, ruptured membranes, or positive signs of infection were not candidates for cerclage placement and were excluded from the analysis. Differences in the prevalence of preterm delivery, mean gestational age at delivery, and mean latency from very short cervix identification to delivery between the 2 groups were calculated. Associations between cerclage and preterm delivery adjusted for maternal characteristics and fetal weight were estimated.

RESULTS

The median gestational ages at the time of cervical length measurement were 20 6/7 weeks (interquartile range, 17 5/7 to 23 3/7) in the cerclage group and 21 5/7 weeks (interquartile range, 17 6/7 to 23 6/7) in the no-cerclage group (P=.02). No difference in cervical length was observed between patients who had a cerclage (5.9±3.1 mm) and those who did not have a cerclage (6.5±3.2 mm) (P=.4). The prevalence of preterm delivery in women with cerclage vs women without cerclage was as follows: PTD at <37 weeks of gestation (31/56 [55.3%] in the cerclage group vs 28/32 [87.5%] in the no-cerclage group; adjusted odds ratio, 0.17; 95% confidence interval, 0.05-0.62; P=.008), PTD at ≤34 weeks of gestation (27/56 [48.2%] in the cerclage group vs 24/32 [75.0%] in the no-cerclage group; adjusted odds ratio, 0.16; 95% confidence interval, 0.05-0.55; P=.02), and PTD at ≤28 weeks of gestation (19/56 [33.9%] in the cerclage group vs 22/32 [68.7%] in the no-cerclage group; adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.51; P=.002). The median gestational ages at delivery were 32 6/7 weeks (interquartile range, 19 1/7 to 40 1/7) in the cerclage group and 28 1/7 weeks (interquartile range, 20 1/7 to 40 2/7) in the no-cerclage group (P=.001). The median latencies from the time of cervical length measurement to delivery were 84 days (interquartile range, 8-144) in the cerclage group and 43 days (interquartile range, 1-146) in the no-cerclage group (P=.003).

CONCLUSION

Among low-risk asymptomatic women with a very short cervix (≤10.0 mm) in the midtrimester of pregnancy, women treated with cerclage have an increased latency to delivery and a lower prevalence of preterm delivery than those treated with expectant management.

The Existence of an Intra-Amniotic Microbiome: Assessing a Controversy

The existence of intra-amniotic and placental microbiomes during pregnancy has been the source of considerable debate, with research yielding conflicting evidence. This study evaluated investigations into the putative presence of these microbiomes in healthy pregnancies by identifying design and data interpretation issues, particularly concerning contamination in samples with low-density bacterial DNA. Positive findings from diverse populations suggest a consistent presence of microbiota in the intra-amniotic space. Negative conclusions regarding the existence of these prenatal microbiomes emphasise the impact of contamination in the analysis of samples with low-density bacterial DNA. This study concluded that there is no definitive evidence to refute the existence of intra-amniotic microbiomes in healthy pregnancies. Also, it provides suggestions for controlling potential contamination factors in future research on intra-amniotic and placental microbial populations.

Assessment of current biomarkers and interventions to identify and treat women at risk of preterm birth

Preterm birth remains an important global problem, and an important contributor to under-5 mortality. Reducing spontaneous preterm birth rates at the global level will require the early identification of patients at risk of preterm delivery in order to allow the initiation of appropriate prophylactic management strategies. Ideally these strategies target the underlying pathophysiologic causes of preterm labor. Prevention, however, becomes problematic as the causes of preterm birth are multifactorial and vary by gestational age, ethnicity, and social context. Unfortunately, current screening and diagnostic tests are non-specific, with only moderate clinical risk prediction, relying on the detection of downstream markers of the common end-stage pathway rather than identifying upstream pathway-specific pathophysiology that would help the provider initiate targeted interventions. As a result, the available management options (including cervical cerclage and vaginal progesterone) are used empirically with, at best, ambiguous results in clinical trials. Furthermore, the available screening tests have only modest clinical risk prediction, and fail to identify most patients who will have a preterm birth. Clearly defining preterm birth phenotypes and the biologic pathways leading to preterm birth is key to providing targeted, biomolecular pathway-specific interventions, ideally initiated in early pregnancy Pathway specific biomarker discovery, together with management strategies based on early, mid-, and-late trimester specific markers is integral to this process, which must be addressed in a systematic way through rigorously planned biomarker trials.

[Prevention of Spontaneous Premature Birth With Cervical Pessary: A Single-Center Prospective Cohort Study]

Objective

To study and compare the clinical effects of cervical pessary and progesterone for preventing preterm birth in singleton pregnant women with a short cervical length (CL).

Methods

This study was a prospective cohort study. A total of 148 pregnant women with CL≤25 mm, as determined by ultrasound examination performed before 28 weeks of pregnancy, were included in the study. All subjects were admitted to West China Second Hospital, Sichuan University between August 2020 and December 2022. According to their treatment plans, the pregnant women were divided into a cervical pessary group (n=55) and a progesterone group (n=93). Spontaneous preterm birth before 37 weeks of pregnancy was defined as the main outcome index. Preterm birth (abortion) or spontaneous preterm birth (abortion) before 37, 34, 32, 30, and 28 weeks of pregnancy, mean extended gestational age, neonatal morbidity, and neonatal mortality were the secondary outcome indicators. The pregnancy outcomes and the neonatal outcomes of the two groups were compared and statistically analyzed.

Results

There was no statistically significant difference in the incidence of preterm birth (including iatrogenic preterm birth, spontaneous preterm birth, and abortion) before 37, 34, 32, 30, and 28 weeks between the cervical pessary group and the progesterone group. When iatrogenic preterm birth was excluded, the incidence of spontaneous preterm birth before 37 weeks was lower in the cervical pessary group (23.6%) than that in the progesterone group (41.9%), with the difference between the two groups being statistically significant (P=0.024). There was no statistically significant difference in the incidence of spontaneous preterm birth (including miscarriage) before 34, 32, 30, and 28 weeks. There was no statistically significant difference in the incidence of neonatal morbidity, the rate of transfer to the neonatal care unit after birth, and the neonatal mortality rate between the two groups. Multivariate logistic analysis showed that treatment with cervical pessary was a protective factor for spontaneous preterm birth before 37 weeks compared to progesterone therapy.

Conclusion

Using cervical pessary to prevent spontaneous preterm birth in singleton pregnant women with a short cervical length in the second trimester can significantly reduce the incidence of spontaneous preterm birth before 37 weeks.

Preventing Preterm Birth: Exploring Innovative Solutions

This review examines the complexities of preterm birth (PTB), emphasizes the pivotal role of inflammation in the pathogenesis of preterm labor, and assesses current available interventions. Antibiotics, progesterone analogs, mechanical approaches, nonsteroidal anti-inflammatory drugs, and nutritional supplementation demonstrate a limited efficacy. Tocolytic agents, targeting uterine activity and contractility, inadequately prevent PTB by neglecting to act on uteroplacental inflammation. Emerging therapies targeting toll-like receptors, chemokines, and interleukin receptors exhibit promise in mitigating inflammation and preventing PTB.

Use and Impact of Pessary, Cerclage, and Progesterone for the Secondary Prevention of Preterm Birth: Data from the German Neonatal Network

BACKGROUND

To evaluate the use and effect of cervical stitch cerclage, pessary, and progesterone on pregnancy outcome in mothers of very low birth weight infants (VLBWI) born<32 weeks of gestation in the German Neonatal Network (GNN).

METHODS

The GNN is a population-based cohort study enrolling VLBWI since 2009. We included 575 neonates from 424 mothers into our analysis, who were born between 2015 and 2019, after prenatal intervention with cerclage, pessary, progesterone or a combination between 20/0 to 25/0 weeks of gestation to prevent preterm birth. Median intervention-to-birth interval was the primary endpoint.

RESULTS

231 of 424 pregnant women had a cerclage only (54.5%), 76 women a pessary only (17.9%), and 27 were prescribed progesterone only (15.3%). The most common combination treatment (>1 intervention group) was cerclage plus progesterone (n=27), followed by cerclage plus pessary (n=13). The median intervention-to-birth interval for the whole cohort was 24 days (IQR 19.0 days). The earlier the intervention was started, the longer the intervention-to-birth interval lasted: When started at 20 weeks, the interval was 34 days in contrast to 11.5 days, when started at 25 weeks. The >1 group was born at a significantly higher median GA with 27.0 weeks (IQR 2.9 weeks) and a higher median birth weight of 980 g (IQR 394 g) accordingly.

CONCLUSION

We propose that the earliest possible start of intervention leads to the most efficient pregnancy prolongation.

The effect of cervical pessary on increasing gestational age at delivery in twin pregnancies with asymptomatic short cervix: a systematic review and meta-analysis of randomized controlled trials

Objective

The incidence of preterm delivery is much higher in twin pregnancies than in singletons and even higher if a short cervical length is detected in the second trimester. Studies are contradictory regarding the efficacy of a cervical pessary to decrease preterm birth in twin pregnancies and short cervical length. To conduct a systematic review and meta-analysis investigating the efficacy of cervical pessary in prolonging gestation, preventing preterm birth, and reducing adverse neonatal outcomes in twin pregnancies with an asymptomatic short cervix.

Data sources

PubMed, Scopus, Web of Science, and ClinicalTrials.org were searched for randomized controlled trials from inception to June 2023.

Study eligibility criteria

In this study, randomized controlled trials comparing the cervical pessary to expectant management in the pregnant population with twin gestations and asymptomatic short cervix were included.

Methods

The Cochrane risk-of-bias-2 tool for randomized controlled trials was used for the evaluation of the risk of bias in included studies. A meta-analysis was performed by calculating risk ratio and mean difference with their 95% confidence interval using the random effects model or fixed effect model on the basis of heterogeneity and accounting for potential covariates among the included randomized controlled trials.

Results

A total of 6 randomized controlled trials were included in the analysis. Cervical pessary did not significantly increase the gestational age at delivery in twin pregnancies with asymptomatic patients (mean difference, 0.36 weeks [-0.27 to 0.99]; P=.270; I2=72.0%). Moreover, the cervical pessary use did not result in a reduction of spontaneous or all-preterm birth before 37 weeks of gestation (risk ratio, 0.88 [0.77-1.00]; P=.061; I2=0.0%). There was no statistically significant difference in the composite neonatal adverse outcomes (risk ratio, 1.001 [0.86-1.16]; P=.981; I2=20.9%), including early respiratory morbidity, intraventricular hemorrhage, necrotizing enterocolitis, and confirmed sepsis.

Conclusion

The use of cervical pessary in twin pregnancies with asymptomatic short cervix does not seem to be effective in increasing the gestational age at delivery, preventing preterm birth, or reducing adverse neonatal outcomes. This indicates that alternative interventions should be sought for the management of this patient population.

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.

Cervical pessary versus vaginal progesterone in women with a singleton pregnancy, a short cervix, and no history of spontaneous preterm birth at less than 34 weeks' gestation: open label, multicentre, randomised, controlled trial

OBJECTIVE

To compare the effectiveness of cervical pessary and vaginal progesterone in the prevention of adverse perinatal outcomes and preterm birth in pregnant women of singletons with no prior spontaneous preterm birth at less than 34 weeks' gestation and who have a short cervix of 35 mm or less.

DESIGN

Open label, multicentre, randomised, controlled trial.

SETTING

20 hospitals and five obstetric ultrasound practices in the Netherlands.

PARTICIPANTS

Women with a healthy singleton pregnancy and an asymptomatic short cervix of 35 mm or less between 18 and 22 weeks' gestation were eligible. Exclusion criteria were prior spontaneous preterm birth at less than 34 weeks, a cerclage in situ, maternal age of younger than 18 years, major congenital abnormalities, prior participation in this trial, vaginal blood loss, contractions, cervical length of less than 2 mm or cervical dilatation of 3 cm or more. Sample size was set at 628 participants.

INTERVENTIONS

1:1 randomisation to an Arabin cervical pessary or vaginal progesterone 200 mg daily up to 36 weeks' of gestation or earlier in case of ruptured membranes, signs of infection, or preterm labour besides routine obstetric care.

MAIN OUTCOME MEASURES

Primary outcome was a composite adverse perinatal outcome. Secondary outcomes were rates of (spontaneous) preterm birth at less than 28, 32, 34, and 37 weeks. A predefined subgroup analysis was planned for cervical length of 25 mm or less.

RESULTS

From 1 July 2014 to 31 March 2022, 635 participants were randomly assigned to pessary (n=315) or to progesterone (n=320). 612 were included in the intention to treat analysis. The composite adverse perinatal outcome occurred in 19 (6%) of 303 participants with a pessary versus 17 (6%) of 309 in the progesterone group (crude relative risk 1.1 (95% confidence interval (CI) 0.60 to 2.2)). The rates of spontaneous preterm birth were not significantly different between groups. In the subgroup of cervical length of 25 mm or less, spontaneous preterm birth at less than 28 weeks occurred more often after pessary than after progesterone (10/62 (16%) v 3/69 (4%), relative risk 3.7 (95% CI 1.1 to 12.9)) and adverse perinatal outcomes seemed more frequent in the pessary group (15/62 (24%) v 8/69 (12%), relative risk 2.1 (0.95 to 4.6)).

CONCLUSIONS

In women with a singleton pregnancy with no prior spontaneous preterm birth at less than 34 weeks' gestation and with a midtrimester short cervix of 35 mm or less, pessary is not better than vaginal progesterone. In the subgroup of a cervical length of 25 mm or less, a pessary seemed less effective in preventing adverse outcomes. Overall, for women with single baby pregnancies, a short cervix, and no prior spontaneous preterm birth less than 34 weeks' gestation, superiority of a cervical pessary compared with vaginal progesterone to prevent preterm birth and consecutive adverse outcomes could not be proven.

TRIAL REGISTRATION

International Clinical Trial Registry Platform (ICTRP, EUCTR2013-002884-24-NL).

Strategies for Safeguarding High-Risk Pregnancies From Preterm Birth: A Narrative Review

Preterm birth is the delivery of a live fetus before the 37th week of gestation. Preterm birth may stem from various factors, including premature rupture of membranes, spontaneous preterm labor, or medically induced circumstances. Premature delivery can result in serious and long-lasting difficulties even for infants who survive, as it is the leading cause of death for infants under five years old. Numerous nations have implemented initiatives to detect and track pregnant women who may give birth before their due date. Numerous therapies are available to protect these at-risk groups from the devastating effects of premature delivery, given the complex nature of preterm birth risk factors. Among the preventive measures, prophylactic progesterone appears to hold significant promise, while cervical cerclage proves effective in cases of cervical insufficiency. Conversely, pessaries show no discernible beneficial effects in reducing the risk of preterm birth. Regular antenatal visits are imperative for frequent patient evaluation and screening for potential risk factors. Adopting a healthy lifestyle can influence the risk of developing preeclampsia, with regular physical activity, a fiber-rich diet, and smoking cessation serving to mitigate the risk of preterm birth. The efficacy of bed rest in preventing preterm birth remains inconclusive due to insufficient evidence. This study aims to explore various preventive strategies for averting premature birth in high-risk women.

Vaginal progesterone for preventing preterm birth and adverse perinatal outcomes in twin gestations: a systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of vaginal progesterone for the prevention of preterm birth and adverse perinatal outcomes in twin gestations.

DATA SOURCES

MEDLINE, Embase, LILACS, and CINAHL (from their inception to January 31, 2023), Cochrane databases, Google Scholar, bibliographies, and conference proceedings.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared vaginal progesterone to placebo or no treatment in asymptomatic women with a twin gestation.

METHODS

The systematic review was conducted according to the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was preterm birth <34 weeks of gestation. Secondary outcomes included adverse perinatal outcomes. Pooled relative risks with 95% confidence intervals were calculated. We assessed the risk of bias in each included study, heterogeneity, publication bias, and quality of evidence, and performed subgroup and sensitivity analyses.

RESULTS

Eleven studies (3401 women and 6802 fetuses/infants) fulfilled the inclusion criteria. Among all twin gestations, there were no significant differences between the vaginal progesterone and placebo or no treatment groups in the risk of preterm birth <34 weeks (relative risk, 0.99; 95% confidence interval, 0.84-1.17; high-quality evidence), <37 weeks (relative risk, 0.99; 95% confidence interval, 0.92-1.06; high-quality evidence), and <28 weeks (relative risk, 1.00; 95% confidence interval, 0.64-1.55; moderate-quality evidence), and spontaneous preterm birth <34 weeks of gestation (relative risk, 0.97; 95% confidence interval, 0.80-1.18; high-quality evidence). Vaginal progesterone had no significant effect on any of the perinatal outcomes evaluated. Subgroup analyses showed that there was no evidence of a different effect of vaginal progesterone on preterm birth <34 weeks of gestation related to chorionicity, type of conception, history of spontaneous preterm birth, daily dose of vaginal progesterone, and gestational age at initiation of treatment. The frequencies of preterm birth <37, <34, <32, <30, and <28 weeks of gestation and adverse perinatal outcomes did not significantly differ between the vaginal progesterone and placebo or no treatment groups in unselected twin gestations (8 studies; 3274 women and 6548 fetuses/infants). Among twin gestations with a transvaginal sonographic cervical length <30 mm (6 studies; 306 women and 612 fetuses/infants), vaginal progesterone was associated with a significant decrease in the risk of preterm birth occurring at <28 to <32 gestational weeks (relative risks, 0.48-0.65; moderate- to high-quality evidence), neonatal death (relative risk, 0.32; 95% confidence interval, 0.11-0.92; moderate-quality evidence), and birthweight <1500 g (relative risk, 0.60; 95% confidence interval, 0.39-0.88; high-quality evidence). Vaginal progesterone significantly reduced the risk of preterm birth occurring at <28 to <34 gestational weeks (relative risks, 0.41-0.68), composite neonatal morbidity and mortality (relative risk, 0.59; 95% confidence interval, 0.33-0.98), and birthweight <1500 g (relative risk, 0.55; 95% confidence interval, 0.33-0.94) in twin gestations with a transvaginal sonographic cervical length ≤25 mm (6 studies; 95 women and 190 fetuses/infants). The quality of evidence was moderate for all these outcomes.

CONCLUSION

Vaginal progesterone does not prevent preterm birth, nor does it improve perinatal outcomes in unselected twin gestations, but it appears to reduce the risk of preterm birth occurring at early gestational ages and of neonatal morbidity and mortality in twin gestations with a sonographic short cervix. However, more evidence is needed before recommending this intervention to this subset of patients.

Cervical Cerclage vs. Pessary in Women with a Short Cervix on Ultrasound

PURPOSE

In the present study we sought to compare the efficacy of cervical pessary to that of cerclage in terms of reducing preterm birth rates among women with a short (<25 mm) or ultra-short (<15 and <10 mm) cervix during the ultrasonographic second-trimester assessment.

METHOD

We retrospectively searched the hospital records for singleton pregnancies diagnosed with cervical insufficiency during the second trimester of pregnancy. The McDonald cerclage using a 5mm Mersilene tape was used in all women. An Arabin pessary was used uniformly. In all cases 80 mg of vaginal progesterone gel were administered daily until 37 weeks of gestation.

RESULTS

Overall, 294 women (124 (42.2%) with a McDonald cerclage and 170 (57.8%) with placement of an Arabin pessary) were selected for analysis. Preterm birth rates <37 weeks were similar in both groups (C: 30/122 vs. P: 35:165, p=.581) as well as PTB <34 weeks (C: 16/122 vs. 15/150, p=.278). Admission to the NICU and need for CPAP were more prevalent in the cerclage group (p<.001). Analysis of cases with a cervix <15 mm and <10 mm indicated that preterm birth rates remained equal among the groups, while an increased risk of NICU admission was seen in cases with a cervical length <10 mm that were treated with cerclage.

DISCUSSION AND CONCLUSION

Cervical pessary may be an alternative to cervical cerclage for women with second-trimester cervical shortening and its effect may persist even among cases with an ultra-short cervix. Future randomized trials are needed to ascertain these findings.

Reassessing Preterm Birth Prevention After the Withdrawal of 17-α Hydroxyprogesterone Caproate

The U.S. Food and Drug Administration has recently withdrawn approval for 17-α hydroxyprogesterone caproate for prevention of recurrent preterm birth, and recent studies have called into question benefits of the pessary in the setting of a short cervix. Obstetric health care professionals are once again left with limited remaining options for preterm birth prevention. This narrative review summarizes the best current evidence on the use of vaginal progesterone, low-dose aspirin, and cerclage for the prevention of preterm birth; attempts to distill possible lessons learned from studies of progesterone and pessary, as well as their implementation into practice; and highlights areas where inroads into preterm birth prevention may be possible outside of the progesterone-aspirin-cerclage paradigm.

The role of vaginal progesterone for preterm birth prevention in women with threatened labor and shortened cervix diagnosed after 24 weeks of pregnancy

OBJECTIVE

To determine whether vaginal progesterone treatment for women with a short cervix, diagnosed after 24 weeks of pregnancy, reduces preterm birth rates.

METHODS

A retrospective cohort study that included women with a singleton pregnancy, threatened preterm labor, and a short cervix measured between 24+0 and 33+6 weeks. Women who received vaginal progesterone were compared with women who did not receive progesterone. The primary outcome was spontaneous preterm birth before 37 weeks of pregnancy.

RESULTS

Patients who received vaginal progesterone had a lower rate of preterm delivery at less than 37 weeks of pregnancy (18.2% [22/121] versus 28.9% [73/253]; adjusted hazard ratio 0.50; 95% confidence interval 0.28-0.73, P = 0.001). The diagnosis-to-delivery interval was significantly greater in patients who received progesterone than in those who did not-median time to delivery in weeks: 8.2 (interquartile range [IQR] 6.2-9.8) versus 6.6 (4.8-8.8), (P < 0.001). The frequency of neonatal intensive care unit admission was significantly lower in patients who received progesterone than in those who did not (8.3% [10/121] versus 16.2% [41/253], P = 0.04).

CONCLUSIONS

The administration of vaginal progesterone to patients with an episode of threatened premature labor and a short cervix presenting after 24 weeks of pregnancy was associated with lower rates of premature births.

Vaginal progesterone for the prevention of preterm birth: who can benefit and who cannot? Evidence-based recommendations for clinical use

Vaginal progesterone (VP) has been recommended to prevent preterm birth (PTB) in women at high-risk. However, there is controversy as to whether VP is efficacious in some subsets of high-risk women. In this review, we examined the current best evidence on the efficacy of VP to prevent PTB in several subsets of high-risk women and provided recommendations for its clinical use. Compelling evidence indicates that VP reduces the risk of PTB and improves perinatal outcomes in singleton gestations with a short cervix (≤25 mm), both with and without a history of spontaneous PTB. VP appears promising to reduce the risk of PTB in twin gestations with a short cervix (≤25 mm) and in singleton gestations conceived by assisted reproductive technologies, but further research is needed. There is no convincing evidence that supports prescribing VP to prevent PTB in singleton gestations based solely on the history of spontaneous preterm birth. Persuasive evidence shows that VP does not prevent PTB nor does it improve perinatal outcomes in unselected twin gestations and in singleton gestations with a history of spontaneous PTB and a cervical length >25 mm. There is no evidence supporting the use of VP to prevent PTB in triplet or higher-order multifetal gestations, singleton gestations with a positive fetal fibronectin test and clinical risk factors for PTB, and gestations with congenital uterine anomalies or uterine leiomyoma. In conclusion, current evidence indicates that VP should only be recommended in singleton gestations with a short cervix, regardless of the history of spontaneous PTB.

GRADE Use in Evidence Syntheses Published in High-Impact-Factor Gynecology and Obstetrics Journals: A Methodological Survey

Objective: To identify and describe the certainty of evidence of gynecology and obstetrics systematic reviews (SRs) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Method: Database searches of SRs using GRADE, published between 1 January 2016 to 31 December 2020, in the 10 "gynecology and obstetrics" journals with the highest impact factor, according to the Journal Citation Report 2019. Selected studies included those SRs using the GRADE approach, used to determine the certainty of evidence. Results: Out of 952 SRs, ninety-six SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Sixty-seven SRs (7.04%) rated the certainty of evidence for specific outcomes. In total, we identified 946 certainty of evidence outcome ratings (n = 614 RCT ratings), ranging from very-low (42.28%) to low (28.44%), moderate (17.65%), and high (11.63%). High and very low certainty of evidence ratings accounted for 2.16% and 71.60% in the SRs of NRSs, respectively, compared with 16.78% and 26.55% in the SRs of RCTs. In the SRs of RCTs and NRSs, certainty of evidence was mainly downgraded due to imprecision and bias risks. Conclusions: More attention needs to be paid to strengthening GRADE acceptance and building knowledge of GRADE methods in gynecology and obstetrics evidence synthesis.

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.

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.

Pessary or progesterone to prevent preterm birth in women with short cervical length: protocol of the 4-6 year follow-up of a randomised controlled trial (Quadruple-P)

INTRODUCTION

Vaginal progesterone and a cervical pessary are both interventions that are investigated for the prevention of preterm birth (PTB). Thus far, beneficial or harmful effects of these interventions on long-term child health and development are described, but evidence is not robust enough to draw firm conclusions. With this follow-up study, we intent to investigate if progesterone or a pessary is superior for the prevention of PTB considering the child's health at 4-6 years of corrected age.

METHODS AND ANALYSIS

This study is a follow-up study of the Quadruple-P trial; a multicentre, randomised clinical trial (NL42926.018.13, Eudractnumber 2013-002884-24) which randomises women with an asymptomatic midtrimester short cervix to daily progesterone or a pessary for the prevention of PTB. All children born to mothers who participated in the Quadruple-P study (n=628 singletons and n=332 multiples) will be eligible for follow-up at 4-6 years of corrected age. Children will be assessed using parental questionnaires. Main outcomes are child (neuro)development and behaviour. Other outcomes include child mortality, growth and general health. A composite of adverse child outcomes will be compared between the progesterone and pessary groups reporting OR and the corresponding 95% CI. Analyses will be performed separately for singletons and multiples and using the intention-to-treat approach.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee from Amsterdam UMC confirmed that de Medical Research Involving Human Subjects Act (WMO) did not apply to our study (W20_481 #20.531). Results will be published in a peer-reviewed journal and shared with stakeholders and participants. This protocol is published before analysis of the results.

TRIAL REGISTRATION NUMBER

Dutch Trial Register (NL9646).

Toward an intravaginal device to detect risk of preterm labor: a user-centered design approach in Sub-Saharan Africa

Background

Prematurity and its complications are the leading cause of death and disability in children under five in Africa and North America, affecting as many as one in ten pregnancies. Screening tests to predict preterm birth (PTB) are insensitive, costly, and often unavailable in low resource settings. In parallel with early-stage U.S.-based testing of a novel self-placed intravaginal device to predict PTB risk, we elicited key stakeholder input from two sub-Saharan African countries to ensure local contextual factors inform future development of the device and its acceptability.

Methods

A qualitative study was conducted in Kiambu County, Kenya and KwaZulu-Natal Province, South Africa. We conducted 26 focus group discussions with pregnant women (n = 132) and males from the community (n = 54); in-depth interviews with women who had a history of PTB (n = 10), healthcare providers (n = 16), and health system experts (n = 10). Interviews were transcribed and thematic analysis was performed using an iterative coding technique. In addition, we facilitated user-centered design sessions to generate prototype preferences.

Results

Women with a personal history of PTB were almost unanimous in support of the proposed device, whereas those with no experience of PTB expressed the greatest degree of reservation. Healthcare providers anticipated that women with a history of PTB would accept the device. However, various potential challenges were identified, including potential discomfort with device insertion, hygiene, and sexual activity, as well as need for provider training, and attention to country-specific regulatory processes. Both community participants and providers expressed a preference for a provider inserted device. Design recommendations included preference for a small, soft, pliable device, with a shape that could facilitate easy removal.

Conclusions

Use of an intravaginal device to detect risk of PTB was generally acceptable, however stakeholders expressed a notable preference for insertion by providers. This reflects the significance of end-user consultation in device design and use. Recommended device modifications as well as educational messaging and provider technical assistance may facilitate utilization.

Prematurity and its complications are the leading cause of death and disability in children under 5 years of age. Up to ten percent of pregnancies in North America and Africa are affected. Screening tests to predict preterm birth (PTB) are insensitive, costly, and often unavailable in low resource settings. A U.S.-based study has developed an intravaginal device to detect preterm labor. In order to assess acceptability and guide development for a low-resource setting, a qualitative study was conducted in Kenya and South Africa. We conducted focus group discussions and interviews with pregnant women, male community members, health care providers and health systems experts. Participants with a personal history of PTB were almost unanimous in support of the proposed device; women with no experience of PTB expressed the greatest degree of reservation. Various potential challenges were identified: discomfort, hygiene, and sexual activity, the need for provider training and attention to country-specific regulatory processes. Design recommendations included preference for a small, soft, pliable device, with a shape that could facilitate easy removal. Stakeholders expressed a strong preference for insertion by providers. These findings reflect the significance of end-user consultation in device design and use.

Prediction and prevention of preterm birth in pregnant women living with HIV on antiretroviral therapy

INTRODUCTION

The rate of spontaneous preterm-birth among pregnant women living with HIV on antiretroviral therapy (ART) is 3- to 4-fold higher when compared to HIV-negative women. The pathophysiology of preterm-birth related to HIV or ART remains unknown, especially as women living with HIV are often excluded from preterm birth studies.

AREAS COVERED

This review discusses the currently available evidence on the prediction and prevention of preterm-birth in pregnant women living with HIV. A review of the literature was conducted of primary articles between 2005 and 2021 measuring the association or lack thereof between combination ART and preterm birth, as well as of other predisposing factors to preterm birth in women living with HIV, including cervical length, vaginal microbiome, and cervico-vaginal biomarkers.

EXPERT OPINION

Further research into the effect of ART exposure on preterm-birth risk is critical, and development of preterm-birth predictive tools in this population should be a priority. Vaginal progesterone supplementation deserves further investigation as a therapeutic option to prevent recurrent preterm birth in pregnant women living with HIV. The ProSPAR study, a multicenter randomized controlled trial studying progesterone supplementation in pregnant women on protease inhibitor-based regimens, has been designed but is not yet recruiting patients.

Preterm Labor: A Comprehensive Review of Guidelines on Diagnosis, Management, Prediction and Prevention

Importance

Preterm labor (PTL) is one of the most common and serious pregnancy complications associated with significant perinatal morbidity and mortality, as well as long-term neurologic impairment in the offspring.

Objective

The aim of this study was to review and compare the most recently published major guidelines on diagnosis, management, prediction, and prevention of this severe complication of pregnancy.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence (NICE), the World Health Organization, the American College of Obstetricians and Gynecologists, the New South Wales Government, and the European Association of Perinatal Medicine (EAPM) on PTL was carried out.

Results

There is a consensus among the reviewed guidelines that the diagnosis of PTL is based on clinical criteria, physical examination, measurement of cervical length (CL) with transvaginal ultrasound (TVUS) and use of biomarkers, although there is disagreement on the first-line diagnostic test. The NICE and the EAPM are in favor of TVUS CL measurement, whereas the New South Wales Government mentions that fetal fibronectin testing is the mainstay for PTL diagnosis. Moreover, there is consistency among the guidelines regarding the importance of treating PTL up to 34 weeks of gestation, to delay delivery for 48 hours, for the administration of antenatal corticosteroids, magnesium sulfate, and in utero transfer to higher care facility, although several discrepancies exist regarding the tocolytic drugs of choice and the administration of corticosteroids and magnesium sulfate after 34 and 30 gestational weeks, respectively. Routine cesarean delivery in case of PTL is unanimously not recommended. Finally, the NICE, the American College of Obstetricians and Gynecologists, and the EAPM highlight the significance of screening for PTL by TVUS CL measurement between 16 and 24 weeks of gestation and suggest the use of either vaginal progesterone or cervical cerclage for the prevention of PTL, based on specific indications. Cervical pessary is not recommended as a preventive measure.

Conclusions

Preterm labor is a significant contributor of perinatal morbidity and mortality with a substantial impact on health care systems. Thus, it seems of paramount importance to develop consistent international practice protocols for timely diagnosis and effective management of this major obstetric complication and subsequently improve pregnancy outcomes.

Progesterone, cervical cerclage or cervical pessary to prevent preterm birth: a decision-making analysis of international guidelines

Objective

The aim of this study was to investigate guidelines on preterm birth, analyze decision-criteria, and to identify consensus and discrepancies among these guidelines.

Design

Objective consensus analysis of guidelines.

Sample

Ten international guidelines on preterm birth.

Methods

Relevant decision criteria were singleton vs. twin pregnancy, history, cervical length, and cervical surgery / trauma or Mullerian anomaly. Eight treatment recommendations were extracted. For each decision-making criteria the most commonly recommended treatment was identified, and the level of consensus was evaluated.

Main outcome measures

Consensus and Discrepancies among recommendations.

Results

In a case of singleton pregnancies with no history of preterm birth and shortened cervix, most guidelines recommend progesterone. In singleton pregnancies with a positive history and shortened cervix, all guidelines recommend a cerclage as an option, alternative or conjunct to progesterone. The majority of the guidelines advise against treatment in twin pregnancies.

Conclusions

A shortened cervix and a history of preterm birth are relevant in singleton pregnancies. In twins, most guidelines recommend no active treatment.

Tweetable abstract

Among international guidelines a shortened cervix and a history of preterm birth are relevant in singleton pregnancies. With no history of preterm birth and with a shortened cervix most guidelines recommend progesterone treatment.

Perinatal care for the extremely preterm infant

Being born preterm (prior to 37 weeks of completed gestation) is a leading cause of childhood death up to five years of age, and is responsible for the demise of around one million preterm infants each year. Rates of prematurity, which range from approximately 5 to 18% of births, are increasing in most countries. Babies born extremely preterm (less than 28 weeks' gestation) and in particular, in the periviable (20^0/7-25^6/7 weeks) period, are at the highest risk of death, or the development of long-term disabilities. The perinatal care of extremely preterm infants and their mothers raises a number of clinical, technical, and ethical challenges. Focusing on 'micropremmies', or those born in the periviable period, this paper provides an update regarding the aetiology and impacts of periviable preterm birth, advances in the antenatal, intrapartum, and acute post-natal management of these infants, and a review of counselling/support approaches for engaging with the infant's family. It concludes with an overview of emerging technology that may assist in improving outcomes for this at-risk population.

Arabin pessary to prevent adverse perinatal outcomes in twin pregnancies with a short cervix: a multicenter randomized controlled trial (PESSARONE)

BACKGROUND

The number of twin pregnancies continues to increase worldwide as both the number of pregnancies obtained by medically assisted reproduction and age at first pregnancy keep rising. Preterm delivery is the major complication associated with twin pregnancies. The effectiveness of preventive treatments such as progesterone or cervical cerclage for women with a short cervix is doubtful in twin pregnancies. The effectivity of cervical pessaries in preventing preterm birth and its associated morbidity and mortality is also controversial.

OBJECTIVE

We sought to investigate if the Arabin pessary reduces adverse neonatal outcomes in twin pregnancies with a short cervix.

STUDY DESIGN

This open-label, multicenter, randomized controlled trial on twin pregnancies with a cervical length of <35 mm compared pessary placement at 16+0 to 24+0 weeks' gestation with standard care alone. The primary endpoint was a composite of adverse neonatal outcomes, namely peripartum or neonatal death or significant neonatal morbidity before hospital discharge, defined as at least 1 of the following complications: bronchopulmonary dysplasia, intraventricular hemorrhage grade III to IV, periventricular leukomalacia, necrotizing enterocolitis grade II or higher, culture-proven sepsis, and retinopathy requiring treatment. A sample size of 308 pregnancies was planned to ensure 80% power to compare the proportions of women with at least 1 infant with an adverse neonatal outcome. The intention-to-treat analysis after multiple imputation of missing data, was supplemented with a secondary analysis that controlled for gestational age and cervical length, both at inclusion. The primary endpoint was also compared between randomization groups in the per-protocol population, which excluded patients with prespecified major protocol violations (mostly cervical cerclage and/or progesterone after inclusion). Secondary endpoints included preterm birth, spontaneous preterm birth, and pessary side effects.

RESULTS

In total, 315 women were randomized to either receive a pessary (n=157) or standard management (n=158). Overall, 10.8% (34 women) of participants had a missing value for the primary endpoint, mostly (79%) because of the lack of paternal consent for neonatal data collection. In the intention-to-treat analysis, the adverse neonatal outcome occurred in 16.8% of the pessary group vs in 22.5% of the control group (risk ratio, 0.69; 95% confidence interval, 0.39-1.23; P=.210). The per-protocol analysis did not show any significant difference between groups (risk ratio, 0.78; 95% confidence interval, 0.47-1.28; P=.320). The occurrence of preterm birth or spontaneous preterm birth did not differ significantly between groups. No serious side effects were associated with pessary use.

CONCLUSION

Pessary use in our study did not significantly reduce adverse neonatal outcomes in twin pregnancies with a short cervix.

Evaluation of midtrimester cervical length thresholds for the prediction of spontaneous preterm birth

INTRODUCTION

To estimate the optimal midtrimester cervical length (CL) threshold for the prediction of spontaneous preterm birth (sPTB) in asymptomatic pregnant women.

MATERIAL AND METHODS

This is a prospective observational cohort study including asymptomatic women with singleton pregnancies who underwent CL measurement by transabdominal and/or transvaginal ultrasound between 19°^/7 and 21^6/7 weeks of gestation. All CL ≤30 mm from transabdominal ultrasound were confirmed by transvaginal ultrasound. Primary outcomes were sPTB <35 and <37 weeks.

RESULTS

Out of 3,449 participants, 28 (0.8%) had a sPTB before 35 weeks and 99 (2.9%) had a sPTB before 37 weeks. Receiver operating characteristics (ROC) curves suggest that a cut-off of 30 mm was the optimal CL to predict sPTB before 35 weeks (sensitivity: 43%; specificity: 97%) and sPTB before 37 weeks (sensitivity: 21%; specificity: 97%). While a CL <25 mm was an important risk factor for sPTB before 35 weeks (relative risk: 31; 95% confidence interval: 13-73), women with a CL between 25 and 30 mm were also at greater risk (relative risk: 12; 95% confidence interval: 4 - 35) compared to women with CL ≥30 mm.

DISCUSSION

A midtrimester CL <30 mm should be considered to identify women at high-risk of sPTB.

Use of cervical elastography at 18 to 22 weeks' gestation in the prediction of spontaneous preterm birth

BACKGROUND

Accurate identification of the women who will have spontaneous preterm birth continues to be a great challenge. The use of cervical elastography for prediction of preterm birth is promising, but several limitations exist. Newer cervical elastography technology has been developed that may prove useful in evaluation of risk of preterm birth.

OBJECTIVE

This study aimed to develop standard cervical elastography nomograms for singleton pregnancies at 18 to 22 weeks' gestation using the E-Cervix ultrasound application, assess intraobserver reliability of the E-Cervix elastography parameters, and determine whether these cervical elastography measurements can be used in the prediction of spontaneous preterm birth.

STUDY DESIGN

This was a prospective cohort study of pregnant women undergoing cervical length screening assessment via transvaginal ultrasound examination at 18 to 22 weeks' gestation. A semiautomatic, cervical elastography application (E-Cervix) was used during the transvaginal examination to calculate 5 quantitative parameters (internal os stiffness, external os stiffness, internal -to -external os stiffness ratio, hardness ratio, and elasticity contrast index) and create a standard nomogram for each one of them. The intraobserver reliability was calculated using Shrout-Fleiss reliability. Cervical elastography parameters were compared between those who delivered preterm (<37 weeks) spontaneously and those who delivered full term. A multivariable logistic regression model was performed to determine the ability of the cervical elastography parameters to predict spontaneous preterm birth.

RESULTS

A total of 742 women were included, of which 49 (6.6%) had a spontaneous preterm delivery. A standard nomogram was created for each of the cervical elastography parameters from those who had a full-term birth in the index pregnancy (n=693). Intraobserver reliability was good or excellent (intraclass correlation, 0.757-0.887) for each of the cervical elastography parameters except external os stiffness which was poor (intraclass correlation, 0.441). In univariate analysis, none of the cervical elastography parameters were associated with a statistically significant increased risk of spontaneous preterm birth. In a multivariable model adjusting for history of preterm birth, gravidity, ethnicity, cervical cerclage, and vaginal progesterone use, increasing elasticity contrast index was significantly associated with an increased risk of spontaneous preterm birth (odds ratio, 1.15; 95% confidence interval, 1.02-1.30; P=.02).

CONCLUSION

Cervical elastography parameters are reliably measured and are stable across 18 to 22 weeks' gestation. Based on our findings, the elasticity contrast index was associated with an increased risk of spontaneous preterm birth and may be a useful parameter for future research.

Prediction and Prevention of Spontaneous Preterm Birth: ACOG Practice Bulletin, Number 234

Preterm birth is among the most complex and important challenges in obstetrics. Despite decades of research and clinical advancement, approximately 1 in 10 newborns in the United States is born prematurely. These newborns account for approximately three-quarters of perinatal mortality and more than one half of long-term neonatal morbidity, at significant social and economic cost (1-3). Because preterm birth is the common endpoint for multiple pathophysiologic processes, detailed classification schemes for preterm birth phenotype and etiology have been proposed (4, 5). In general, approximately one half of preterm births follow spontaneous preterm labor, about a quarter follow preterm prelabor rupture of membranes (PPROM), and the remaining quarter of preterm births are intentional, medically indicated by maternal or fetal complications. There are pronounced racial disparities in the preterm birth rate in the United States. The purpose of this document is to describe the risk factors, screening methods, and treatments for preventing spontaneous preterm birth, and to review the evidence supporting their roles in clinical practice. This Practice Bulletin has been updated to include information on increasing rates of preterm birth in the United States, disparities in preterm birth rates, and approaches to screening and prevention strategies for patients at risk for spontaneous preterm birth.

Multifetal Gestations: Twin, Triplet, and Higher-Order Multifetal Pregnancies: ACOG Practice Bulletin, Number 231

The incidence of multifetal gestations in the United States has increased dramatically over the past several decades. For example, the rate of twin births increased 76% between 1980 and 2009, from 18.9 to 33.3 per 1,000 births (1). However, after more than three decades of increases, the twin birth rate declined 4% during 2014-2018 to 32.6 twins per 1,000 total births in 2018 (2). The rate of triplet and higher-order multifetal gestations increased more than 400% during the 1980s and 1990s, peaking at 193.5 per 100,000 births in 1998, followed by a modest decrease to 153.4 per 100,000 births by 2009 (3). The triplet and higher-order multiple birth rate was 93.0 per 100,000 births for 2018, an 8% decline from 2017 (101.6) and a 52% decline from the 1998 peak (193.5) (4). The long-term changes in the incidence of multifetal gestations has been attributed to two main factors: 1) a shift toward an older maternal age at conception, when multifetal gestations are more likely to occur naturally, and 2) an increased use of assisted reproductive technology (ART), which is more likely to result in a multifetal gestation (5). A number of perinatal complications are increased with multiple gestations, including fetal anomalies, preeclampsia, and gestational diabetes. One of the most consequential complications encountered with multifetal gestations is preterm birth and the resultant infant morbidity and mortality. Although multiple interventions have been evaluated in the hope of prolonging these gestations and improving outcomes, none has had a substantial effect. The purpose of this document is to review the issues and complications associated with twin, triplet, and higher-order multifetal gestations and present an evidence-based approach to management.

Use of the Arabin pessary in women at high risk for preterm birth: long-term experience at a single tertiary center in Malaysia

Background

Spontaneous preterm birth is a global issue that contributed to perinatal morbidities and mortalities worldwide. The study aimed to describe the experience at UKM Medical Center in managing women at high risk for spontaneous preterm birth using the Arabin pessary.

Methods

This is a retrospective observational study involving 58 pregnancies from 1st January 2013 to 31st December 2019. Inclusion criteria were previous mid-trimester miscarriage and/or preterm birth, previous cervical surgery or short cervical length on routine sonogram. The demographic data, characteristics of each pregnancy and details of outcomes and management were described.

Results

The majority of women were Malay with mean age and body mass index of 32.9 ± 4.2 years and 27.1 ± 6.3 kg/m² respectively. The most frequent indications for Arabin pessary insertion were previous mid-trimester miscarriage (46.4%) and early preterm birth (17.2%). A total of 73.4% of these women had the pessary inserted electively at a mean cervical length of 31.6 ± 9.1 mm at median gestation of 15.0 weeks. They were managed as outpatient (56.9%), inpatient (24.1%) or mixed (19.0%) with combination of progestogen (81.0%) and 53.4% received antenatal corticosteroids. Spontaneous preterm birth at or more than 34 weeks gestation occurred in 74.1% with birthweight at or more than 2000 g (82.4%). Despite cervical funneling in 12 women (20.7%), 66.7% delivered at or later than 34 weeks gestation and 2 (16.7%) resulted in miscarriage.

Conclusions

Insertion of the Arabin pessary is beneficial to prevent spontaneous preterm birth in pregnant women who are at high risk. In particular, early insertion and close monitoring allows the best possible outcomes.

Trial registration

This study was retrospectively registered with ClinicalTrials.gov (NCT04638023) on 20/11/2020.

Evaluation of the Arabin cervical pessary for prevention of preterm birth in women with a twin pregnancy and short cervix (STOPPIT-2): An open-label randomised trial and updated meta-analysis

BACKGROUND

Preterm-labour-associated preterm birth is a common cause of perinatal mortality and morbidity in twin pregnancy. We aimed to test the hypothesis that the Arabin pessary would reduce preterm-labour-associated preterm birth by 40% or greater in women with a twin pregnancy and a short cervix.

METHODS AND FINDINGS

We conducted an open-label randomised controlled trial in 57 hospital antenatal clinics in the UK and Europe. From 1 April 2015 to 14 February 2019, 2,228 women with a twin pregnancy underwent cervical length screening between 18 weeks 0 days and 20 weeks 6 days of gestation. In total, 503 women with cervical length ≤ 35 mm were randomly assigned to pessary in addition to standard care (n = 250, mean age 32.4 years, mean cervical length 29 mm, with pessary inserted in 230 women [92.0%]) or standard care alone (n = 253, mean age 32.7 years, mean cervical length 30 mm). The pessary was inserted before 21 completed weeks of gestation and removed at between 35 and 36 weeks or before birth if earlier. The primary obstetric outcome, spontaneous onset of labour and birth before 34 weeks 0 days of gestation, was present in 46/250 (18.4%) in the pessary group compared to 52/253 (20.6%) following standard care alone (adjusted odds ratio [aOR] 0.87 [95% CI 0.55-1.38], p = 0.54). The primary neonatal outcome-a composite of any of stillbirth, neonatal death, periventricular leukomalacia, early respiratory morbidity, intraventricular haemorrhage, necrotising enterocolitis, or proven sepsis, from birth to 28 days after the expected date of delivery-was present in 67/500 infants (13.4%) in the pessary group compared to 76/506 (15.0%) following standard care alone (aOR 0.86 [95% CI 0.54-1.36], p = 0.50). The positive and negative likelihood ratios of a short cervix (≤35 mm) to predict preterm birth before 34 weeks were 2.14 and 0.83, respectively. A meta-analysis of data from existing publications (4 studies, 313 women) and from STOPPIT-2 indicated that a cervical pessary does not reduce preterm birth before 34 weeks in women with a short cervix (risk ratio 0.74 [95% CI 0.50-1.11], p = 0.15). No women died in either arm of the study; 4.4% of babies in the Arabin pessary group and 5.5% of babies in the standard treatment group died in utero or in the neonatal period (p = 0.53). Study limitations include lack of power to exclude a smaller than 40% reduction in preterm labour associated preterm birth, and to be conclusive about subgroup analyses.

CONCLUSIONS

These results led us to reject our hypothesis that the Arabin pessary would reduce the risk of the primary outcome by 40%. Smaller treatment effects cannot be ruled out.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN 02235181. ClinicalTrials.gov NCT02235181.

Uterovesical fistula caused by cervical pessary placed for the prevention of preterm delivery - case report

Uterovesical fistulas are the rarest of all urogenital fistulas, mostly occurring as a complication of cesarean section. We present a case of a 32-year-old woman, who noticed continuous vaginal urine leakage starting immediately after a vaginal delivery. The shortening of the uterine cervix was reported at 26^th week of gestation, and a cervical pessary was placed. Shortly after delivery, the patient noticed the loss of urinary continence control, and she was diagnosed with urinary incontinence and hematuria. The office diagnostic hysteroscopy revealed uterovesical fistula. The correction procedure by transabdominal approach was performed by the team of gynecological and urological surgeons. One year of follow-up, the patient reports no symptoms related to lower urinary tract dysfunction. Based on the literature search, we believe that his is the first study of a uterovesical fistula followed by the use of a cervical pessary for the prevention of preterm delivery. Our case is a clear reminder that symptoms of urinary incontinence after vaginal delivery should be carefully managed.

The Risk of Preterm Birth in Women with Three Consecutive Deliveries-The Effect of Number and Type of Prior Preterm Births

Background: We aimed to explore the association of the number, order, gestational age and type of prior PTB and the risk of preterm birth (PTB) in the third delivery in women who had three consecutive singleton deliveries. Methods: A retrospective cohort study of all women who had three consecutive singleton births at a single medical center over a 20-year period (1994-2013). The primary outcome was PTB (<37 weeks) in the third delivery. Results: 4472 women met inclusion criteria. The rate of PTB in the third delivery was 4.9%. In the adjusted analysis, the risk of PTB was 3.5% in women with no prior PTBs; 10.9% in women with prior one PTB only in the first pregnancy; 16.2% in women with prior one PTB only in the second pregnancy; and 56.5% in women with prior two PTBs. A similar trend was observed when the outcome of interest was spontaneous PTB and when the exposure was limited to prior spontaneous or indicated PTB. Conclusions: In women with a history of PTB, the risk of recurrent PTB in subsequent pregnancies is related to the number and order of prior PTBs. These factors should be taken into account when stratifying the risk of PTB.

Current Preterm Birth Prevention Strategies

Preterm birth remains a major issue in obstetrics. Despite efforts to reduce the incidence of preterm delivery, rates in the United States remain high at 10.2% of all live births with an incidence of 10.8% globally. Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. It is also the leading cause of death in children younger than 5 years. Research into this important health topic has allowed for the identification of risk factors for preterm birth, the most important of which is a history of prior preterm birth. Cervical length screening may allow us to identify those at greatest risk of recurrent preterm birth as well as a de novo risk in women with no prior preterm birth history.

The impact of funneling shape on the secondary prevention of spontaneous preterm birth in patients treated with either an Arabin pessary, McDonald cerclage or early total cervical occlusion (ETCO)

OBJECTIVE

Cervical funneling is associated with spontaneous preterm birth (sPTB). The aim of this analysis was to assess the relationship between funneling shape and the response to the McDonald cerclage, the Arabin pessary and the early total cervical occlusion (ETCO).

METHODS

We retrospectively analyzed data of 312 randomly selected singleton pregnancies with cervical shortening <25 mm or normal cervical length and evaluated them according to the progression of funneling: control group (n = 46), cervical shortening without funneling (n = 107), V-shaped funneling (n = 68), U-shaped funneling (n = 47), and prolapse of the amniotic sac (n = 44). We evaluated sPTB rates <34, <28, <32, and <37 weeks as well as prolongation of gestation and birthweight.

RESULTS

Regarding the rate of sPTB <34 weeks there was no statistical significance in either of the comparisons between control group and each of the four risk groups. Regarding prolongation of gestation we demonstrated a statistical significance for all risk groups compared to the control group (all p < .05) with the lowest prolongation rate noted in the group with amnion prolapse and the highest in the group with isolated cervical shortening without funneling. Similarly, progression of funnel shape resulted in an absolute decrease of birthweight for all risk groups compared to the control group, albeit not significant for the group with U-shaped funneling (p = .1058).

CONCLUSION

Independent of the treatment, there was a significant impact of funneling shape on pregnancy duration and birthweight.

Novel pathways of inflammation in human fetal membranes associated with preterm birth and preterm pre-labor rupture of the membranes

Spontaneous preterm birth (PTB) and preterm pre-labor rupture of the membranes (pPROM) are major pregnancy complications. Although PTB and pPROM have common etiologies, they arise from distinct pathophysiologic pathways. Inflammation is a common underlying mechanism in both conditions. Balanced inflammation is required for fetoplacental growth; however, overwhelming inflammation (physiologic at term and pathologic at preterm) can lead to term and preterm parturition. A lack of effective strategies to control inflammation and reduce the risk of PTB and pPROM suggests that there are several modes of the generation of inflammation which may be dependent on the type of uterine tissue. The avascular fetal membrane (amniochorion), which provides structure, support, and protection to the intrauterine cavity, is one of the key contributors of inflammation. Localized membrane inflammation helps tissue remodeling during pregnancy. Two unique mechanisms that generate balanced inflammation are the progressive development of senescence (aging) and cyclic cellular transitions: epithelial to mesenchymal (EMT) and mesenchymal to epithelial (MET). The intrauterine build-up of oxidative stress at term or in response to risk factors (preterm) can accelerate senescence and promote a terminal state of EMT, resulting in the accumulation of inflammation. Inflammation degrades the matrix and destabilizes membrane function. Inflammatory mediators from damaged membranes are propagated via extracellular vesicles (EV) to maternal uterine tissues and transition quiescent maternal uterine tissues into an active state of labor. Membrane inflammation and its propagation are fetal signals that may promote parturition. This review summarizes the mechanisms of fetal membrane cellular senescence, transitions, and the generation of inflammation that contributes to term and preterm parturitions.