Uterocervical angle versus cervical length in the prediction of spontaneous preterm birth in women with history of spontaneous preterm birth: a prospective observational study

BACKGROUND

Preterm delivery is a leading cause of neonatal mortality and morbidity. History of spontaneous preterm birth is the greatest risk factor for another preterm delivery. So, every effort should be made to prevent the recurrence of preterm delivery in this vulnerable group. This study aimed to evaluate the predictive ability of the anterior uterocervical angle and cervical length in preterm birth.

PATIENTS AND METHODS

This was a prospective cohort study that included 70 patients with a history of spontaneous preterm birth. Ultrasound measurements of cervical length and anterior uterocervical angle were set to be measured for each patient at three visits; first between 16 0/7 and 24 0/7 weeks, second between 24 1/7 and 32 0/7 weeks, and the third was between 32 1/7 and 36 6/7 weeks. The correlation between both measures and the prediction of preterm birth among study participants was the primary outcome of the study. Neonatal outcome among the study patients was a secondary measure of outcome.

RESULTS

The incidence of preterm birth among study participants was 31.41%. Cervical length and uterocervical angle showed progressive decrease and increase respectively throughout pregnancy. At the 2nd visit, the two measures were significantly different between those who delivered at term and those with preterm delivery with the cervical length being significantly shorter in the preterm arm (3.0 ± 0.49 versus 3.38 ± 0.36, p < 0.001) and uterocervical angle being significantly bigger among the same arm (110.1 ± 18.48 versus 84.42 ± 12.24, p < 0.001). A uterocervical angle > 89.8° at the second visit predicted preterm birth with 81.8% sensitivity and 70.8% specificity while cervical length ≤ 3.22 cm at the second visit predicted preterm birth with 68.1% sensitivity and 62.5% specificity. Multivariant logistic regression analysis showed that uterocervical angle > 89.8° at the second visit increased the odds ratio for preterm birth by 9.

CONCLUSION

Uterocervical angle can be a useful ultrasound marker for the prediction of preterm birth among high risk patients. A cutoff value of 89.8° can be used as a threshold above which prophylactic measures such as cervical cerclage or progesterone therapy can be provided.

TRIAL REGISTRATION

NCT05632003 (First posted date: 30/11/2022).

Removal versus retention of cervical cerclage with preterm prelabor rupture of membranes: Systematic review and meta-analysis

OBJECTIVE

To evaluate maternal and perinatal outcomes of removal versus retention of cervical cerclage after premature preterm rupture of membranes (pPROM).

STUDY DESIGN

Medline, Embase and Cochrane databases were searched electronically on February 2023 utilizing combinations of the relevant medical subject heading (MeSH) terms, keywords, and word variants that were considered suitable for the topic. Either prospective or retrospective trials were considered suitable for the inclusion. The coprimary outcome of this study were pregnancy latency >7 days from pPROM and pregnancy latency >48 h from pPROM. Random effect head to-head meta-analyses were performed to directly compare each outcome, expressing the results as summary odds ratio (OR) for dichotomous outcomes and as mean difference (MD) for continuous outcomes, plus relative 95% confidence interval (CI). Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale.

RESULTS

Six studies involving a total of 377 women (169 in the "removal" and 208 in the "retention" group) were included. The rate of pregnancy prolongation >48 h was significantly lower in the removal compared to retention group (OR 0.15, 95% CI 0.07-0.31; p < 0.0001), as well as the rate of pregnancy prolongation >7 days (OR 0.30 95% CI 0.11-0.83; p = 0.02) and pregnancy latency expressed in days (MD -2.84 days, 95% CI -5.40 to -0.29; p = 0.03). The rate of chorioamnionitis was significantly lower in the removal compared to the retention group (OR 0.57 95% CI 0.34-0.96p = 0.03) as was the rate of Apgar score < 7 at 5 min (OR 0.22 95% CI 0.08-0.56; p = 0.002). There was no difference between removal and retention groups for all the other maternal and perinatal outcomes.

CONCLUSIONS

The decision whether to remove or retain cerclage in case of pPROM should balance the prematurity-related risks with that of infectious complications, thus highlighting the need for tailored management based on gestational age at occurrence of pPROM.

Short cervix and preterm birth in the top end

BACKGROUND

Reducing rates of preterm birth (PTB) remains a significant challenge. The Northern Territory (NT) records some of the highest rates of PTB in the country, especially in First Nations women. In 2014, a Western Australian (WA) preterm birth prevention initiative involved the implementation of seven key initiatives. One of these was routine mid-trimester cervical length measurement. The initiative successfully reduced PTB rates following its first year of implementation. This was the first successful reduction in PTB, including the earlier gestational ages, across a population.

AIMS

To assess the uptake of routine cervical length measurement in the Top End of the NT after the success of the WA PTB prevention initiative and assess if treatment of a short cervix improved PTB rates.

METHODS

A retrospective cohort study of all women who received antenatal care and delivered their baby at the NT's only tertiary hospital was performed. Mid-trimester ultrasound scan data were collected from two separate time windows, before and after the implementation of the WA intervention. Treatments and gestational age at birth were recorded.

RESULTS

Adoption of routine screening of cervical length measurement at mid-trimester ultrasound in the NT was successful, increasing from 4 to 88%. Detection rates of short cervix doubled. However, there was no difference to PTB rates despite targeted management.

CONCLUSION

PTB remains a significant challenge in the NT, especially for First Nations women who are found to have a short cervix more commonly than non-Indigenous women in the Top End.

Cervical cerclage for prevention of preterm birth and adverse perinatal outcome in twin pregnancies with short cervical length or cervical dilatation: A systematic review and meta-analysis

BACKGROUND

The optimal approach to prevent preterm birth (PTB) in twins has not been fully established yet. Recent evidence suggests that placement of cervical cerclage in twin pregnancies with short cervical length at ultrasound or cervical dilatation at physical examination might be associated with a reduced risk of PTB. However, such evidence is based mainly on small studies thus questioning the robustness of these findings. The aim of this systematic review was to determine the role of cervical cerclage in preventing PTB and adverse maternal or perinatal outcomes in twin pregnancies.

METHODS AND FINDINGS

Key databases searched and date of last search: MEDLINE, Embase, and CINAHL were searched electronically on 20 April 2023. Eligibility criteria: Inclusion criteria were observational studies assessing the risk of PTB among twin pregnancies undergoing cerclage versus no cerclage and randomized trials in which twin pregnancies were allocated to cerclage for the prevention of PTB or to a control group (e.g., placebo or treatment as usual). The primary outcome was PTB <34 weeks of gestation. The secondary outcomes were PTB <37, 32, 28, 24 weeks of gestation, gestational age at birth, the interval between diagnosis and birth, preterm prelabor rupture of the membranes (pPROM), chorioamnionitis, perinatal loss, and perinatal morbidity. Subgroup analyses according to the indication for cerclage (short cervical length or cervical dilatation) were also performed. Risk of bias assessment: The risk of bias of the included randomized controlled trials (RCTs) was assessed using the Revised Cochrane risk-of-bias tool for randomized trials, while that of the observational studies using the Newcastle-Ottawa scale (NOS). Statistical analysis: Summary risk ratios (RRs) of the likelihood of detecting each categorical outcome in exposed versus unexposed women, and (b) summary mean differences (MDs) between exposed and unexposed women (for each continuous outcome), with their 95% confidence intervals (CIs) were computed using head-to-head meta-analyses. Synthesis of the results: Eighteen studies (1,465 twin pregnancies) were included. Placement of cervical cerclage in women with a twin pregnancy with a short cervix at ultrasound or cervical dilatation at physical examination was associated with a reduced risk of PTB <34 weeks of gestation (RR: 0.73, 95% CI [0.59, 0.91], p = 0.005 corresponding to a 16% difference in the absolute risk, AR), <32 (RR: 0.69, 95% CI [0.57, 0.84], p < 0.001; AR: 16.92%), <28 (RR: 0.54, 95% [CI 0.43, 0.67], 0.001; AR: 18.29%), and <24 (RR: 0.48, 95% CI [0.23, 0.97], p = 0.04; AR: 15.57%) weeks of gestation and a prolonged gestational age at birth (MD: 2.32 weeks, 95% [CI 0.99, 3.66], p < 0.001). Cerclage in twin pregnancy with short cervical length or cervical dilatation was also associated with a reduced risk of perinatal loss (RR: 0.38, 95% CI [0.25, 0.60], p < 0.001; AR: 19.62%) and composite adverse outcome (RR: 0.69, 95% CI [0.53, 0.90], p = 0.007; AR: 11.75%). Cervical cerclage was associated with a reduced risk of PTB <34 weeks both in women with cervical length <15 mm (RR: 0.74, 95% CI [0.58, 0.95], p = 0.02; AR: 29.17%) and in those with cervical dilatation (RR: 0.68, 95% CI [0.57, 0.80], p < 0.001; AR: 35.02%). The association between cerclage and prevention of PTB and adverse perinatal outcomes was exclusively due to the inclusion of observational studies. The quality of retrieved evidence at GRADE assessment was low.

CONCLUSIONS

Emergency cerclage for cervical dilation or short cervical length <15 mm may be potentially associated with a reduction in PTB and improved perinatal outcomes. However, these findings are mainly based upon observational studies and require confirmation in large and adequately powered RCTs.

Cervical cerclage in twin pregnancies: obstetric and neonatal outcomes

BACKGROUND

Although there have been significant improvements in prenatal and neonatal care in recent years, twin pregnancies account for 17-20% of all preterm births and are associated with an increased risk of perinatal mortality and morbidity.

AIMS

To evaluate the contribution of cerclage to the continuation of pregnancy in twin pregnancy cases required cervical cerclage.

METHODS

Cases of twin pregnancies who performed cervical cerclage with follow-up and deliveries between January 2010 and January 2022 in the Department of Obstetrics and Gynecology, Ege University Faculty of Medicine Hospital, were retrospectively analyzed. Obstetric and neonatal outcomes were evaluated.

RESULTS

A total of 23 women who performed cervical cerclage due to cervical insufficiency in twin pregnancies were evaluated retrospectively. The mean time between cerclage placement and delivery was 12.1 ± 7 weeks, maximum prolongation was in the obstetric history-indicated cerclage group. The gestational age at delivery was 20-38 (median 30) weeks. The rate of spontaneous preterm birth at < 34, < 32, < 28, and < 24 weeks was higher in the physical examination-indicated cerclage group. Overall neonatal survival was 82.5% (n = 33/40).

CONCLUSION

The time between cerclage placement and birth were considered as an important gain for twin pregnancies at the limit of viability. Further studies are needed to better understand the role of cervical cerclage in preventing premature birth and to determine the indications for cerclage.

Combined vaginal progesterone and cervical cerclage in the prevention of preterm birth: a systematic review and meta-analysis

OBJECTIVE

Vaginal progesterone and cervical cerclage are both effective interventions for reducing preterm birth. It is currently unclear whether combined therapy offers superior effectiveness than single therapy. This study aimed to determine the efficacy of combining cervical cerclage and vaginal progesterone in the prevention of preterm birth.

DATA SOURCES

We searched Medline (Ovid), EMBASE (Ovid), PsycINFO (Ovid), CINAHL (EBSCOhost), Cochrane Library (Wiley), and Scopus (from their inception to 2020).

STUDY ELIGIBILITY CRITERIA

The review accepted randomized and pseudorandomized control trials, nonrandomized experimental control trials, and cohort studies. High risk patients (shortened cervical length <25mm or previous preterm birth) who were assigned cervical cerclage, vaginal progesterone, or both for the prevention of preterm birth were included. Only singleton pregnancies were assessed.

METHODS

The primary outcome was birth <37 weeks. Secondary outcomes included birth <28 weeks, <32 weeks and <34 weeks, gestational age at delivery, days between intervention and delivery, preterm premature rupture of membranes, cesarean delivery, neonatal mortality, neonatal intensive care unit admission, intubation, and birthweight. Following title and full-text screening, 11 studies were included in the final analysis. Risk of bias was assessed using the Cochrane Collaboration tool for assessing the risk of bias (ROBINS-I and RoB-2). Quality of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) tool.

RESULTS

Combined therapy was associated with lower risk of preterm birth at <37 weeks than cerclage alone (risk ratio, 0.51; 95% confidence interval, 0.37-0.79) or progesterone alone (risk ratio, 0.75; 95% confidence interval, 0.58-0.96). Compared with cerclage only, combined therapy was associated with preterm birth at <34 weeks, <32 weeks, or <28 weeks, decreased neonatal mortality, increased birthweight, increased gestational age, and a longer interval between intervention and delivery. Compared with progesterone alone, combined therapy was associated with preterm birth at <32 weeks, <28 weeks, decreased neonatal mortality, increased birthweight, and increased gestational age. There were no differences in any other secondary outcomes.

CONCLUSION

Combined treatment of cervical cerclage and vaginal progesterone could potentially result in a greater reduction in preterm birth than in single therapy. Further, well-conducted and adequately powered randomized controlled trials are needed to assess these promising findings.

Immune-checkpoint proteins, cytokines, and microbiome impact on patients with cervical insufficiency and preterm birth

Background

Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical insufficiency and preterm delivery. These factors are incompletely understood. This study aimed to explore and compare interactions among microbiome and inflammatory factors, such as cytokines and immune-checkpoint proteins, in patients with cervical insufficiency and preterm birth. In particular, factors related to predicting preterm birth were identified and the performance of the combination of these factors was evaluated.

Methods

A total of 220 swab samples from 110 pregnant women, prospectively recruited at the High-Risk Maternal Neonatal Intensive Care Center, were collected between February 2020 and March 2021. This study included 63 patients with cervical insufficiency receiving cerclage and 47 control participants. Endo- and exocervical swabs and fluids were collected simultaneously. Shotgun metagenomic sequencing for the microbiome and the measurement of 34 immune-checkpoint proteins and inflammatory cytokines were performed.

Results

First, we demonstrated that immune-checkpoint proteins, the key immune-regulatory molecules, could be measured in endocervical and exocervical samples. Secondly, we identified significantly different microenvironments in cervical insufficiency and preterm birth, with precise cervical locations, to provide information about practically useful cervical locations in clinical settings. Finally, the presence of Moraxella osloensis (odds ratio = 14.785; P = 0.037) and chemokine CC motif ligand 2 levels higher than 73 pg/mL (odds ratio = 40.049; P = 0.005) in endocervical samples were associated with preterm birth. Combining M. osloensis and chemokine CC motif ligand 2 yielded excellent performance for predicting preterm birth (area under the receiver operating characteristic curve = 0.846, 95% confidence interval = 0.733-0.925).

Conclusion

Multiple relationships between microbiomes, immune-checkpoint proteins, and inflammatory cytokines in the cervical microenvironment were identified. We focus on these factors to aid in the comprehensive understanding and therapeutic modulation of local microbial and immunologic compositions for the management of cervical insufficiency and preterm birth.

Twenty years of experience with less radical fertility-sparing surgery in early-stage cervical cancer: Pregnancy outcomes

INTRODUCTION

The standard procedure in cervical cancer is radical hysterectomy and pelvic lymphadenectomy (PLND). Because of the increasing age of women bearing children, fertility has become a major challenge. We present pregnancy results after less radical fertility-sparing surgery in women with IA1, LVSI positive, IA2 and IB1 (<2 cm, infiltration less than half of the cervical stroma).

MATERIALS AND METHOD

All women (n = 91) underwent laparoscopic sentinel lymph node mapping with frozen section followed by PLND and "selective parametrectomy" (removal of afferent lymphatic channels from the paracervix) if sentinel nodes (SLN) are negative. If lymph nodes were verified negative by definitive histopathology, patients were treated by simple trachelectomy (IB1) or large cone (IA1/IA2) biopsy 1 week after primary surgery.

RESULTS

From 1999 to 2018, 91 women were enrolled in the study (median age 29.1 years, range 21-40). Fertility was spared in 76 (83.5%) women; 13 (17.1%) women did not plan future pregnancy and 63 (82.9%) had pregnancy desires. Fifty-four of 63 women conceived (pregnancy rate 85.7%) and 48 of 63 delivered 58 babies (delivery rate 76.2%). Thirty-nine women delivered in term (67.2%): 13 women between 32 and 36 + 6 weeks of pregnancy, 3 between 28 and 31 + 6 weeks and 3 between 24 and 27 + 6 weeks. Only one woman still plans pregnancy. One woman is currently pregnant.

CONCLUSION

The goal of fertility-sparing surgery is to produce good oncological results and promising pregnancy outcomes. Pregnancy results after less radical fertility-sparing procedures show promise (pregnancy rate 82.9% and delivery rate 76.2%).

Predicting spontaneous preterm birth in asymptomatic high-risk women with cervical cerclage

OBJECTIVE

To determine the performance of the predictive markers of spontaneous preterm birth, cervicovaginal quantitative fetal fibronectin (fFN) and cervical length, in asymptomatic high-risk women with transabdominal, history-indicated or ultrasound-indicated cervical cerclage.

METHODS

This was a secondary analysis of a prospective cohort of asymptomatic high-risk women with cervical cerclage and no other prophylactic intervention (including progesterone), who attended the preterm birth clinic at a central London teaching hospital between October 2010 and September 2016. Women had either transabdominal cerclage, placed prior to conception, history-indicated cerclage, placed before 14 weeks' gestation, or ultrasound-indicated cerclage for a short cervix (< 25 mm), placed before 24 weeks. All women underwent serial cervical length assessment on transvaginal ultrasound in the second trimester (16-28 weeks), and quantitative fFN testing from 18 weeks onward. Test performance was analyzed for the prediction of spontaneous preterm birth before 30 weeks (cerclage failure), 34 weeks and 37 weeks, using receiver-operating-characteristics (ROC)-curve analysis.

RESULTS

Overall, 181 women were included in the analysis. Cervical length and fFN were strong predictors of spontaneous preterm birth before 30 weeks in women with cerclage, with areas under the ROC curve (AUC) of 0.86 (95% CI, 0.79-0.94) and 0.84 (95% CI, 0.75-0.92), respectively. Cervical length was a better predictor of preterm birth before 30 weeks in women with history-indicated compared to those with ultrasound-indicated cerclage, although both showed clinical utility (AUC, 0.96 (95% CI, 0.91-1.00) vs 0.79 (95% CI, 0.66-0.91); P = 0.01). Quantitative fFN was a strong predictor of spontaneous preterm birth before 30 weeks in women with history-indicated cerclage (AUC, 0.91 (95% CI, 0.75-1.00)) and retained clinical utility in those with ultrasound-indicated cerclage (AUC, 0.76 (95% CI, 0.64-0.89)). There were no spontaneous deliveries before 34 weeks in women with a transabdominal cerclage, so AUC was not calculated. Delivery was delayed significantly in this group (P < 0.01).

CONCLUSIONS

Cervical length and quantitative fFN retain clinical utility for the prediction of spontaneous preterm birth in women with cervical cerclage, and prediction is best in women with a history-indicated stitch. These tests can be relied upon to discriminate risk and have utility when planning clinical management with regard to treatment failure. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Cervical cerclage training: Development and assessment of a simulator

BACKGROUND

Cervical cerclage is a mainstay intervention for the prevention of spontaneous preterm birth in high-risk women. Simulation training facilitates high-level skill transfer in a low-consequence environment, and is being integrated into obstetrics and gynecology training.

OBJECTIVE

This study aimed to develop a simulator for cervical cerclage, determine its validity as a simulator, and identify parameters suitable as proxy markers for performance.

STUDY DESIGN

The 3 aims of this study were achieved, namely: (1) simulator design by obstetricians and a commercial company; (2) survey of obstetricians and gynecologists across a variety of training stages to determine need for and opinion of the simulator; and (3) comparison of novice and expert groups across a variety of proxy markers for successful cerclage insertion.

RESULTS

Obstetricians and gynecologists found the simulator to be similar to clinical scenarios and suitable for skill training. Novice participants stated that the use of the simulator improved their confidence (P=.016). In a comparison between 6 expert and 8 novice surgeons, there seemed to be variations across multiple measurements of cerclage placement.

CONCLUSION

Simulation is an increasingly prominent training modality for surgical skills. The simulator described herein was considered suitable for training by obstetricians and gynecologists. Further work should focus on the validations of proxy markers of successful insertion, longitudinal assessment of trainees, and correlation of training outcomes with clinical outcomes.

Incidentally Found Midtrimester Shortened Cervical Length: Practice Patterns among American Maternal-Fetal Medicine Specialists

OBJECTIVE

The management of incidentally found short cervical length (CL) without prior spontaneous preterm birth (PTB) can vary. While most agree on starting vaginal progesterone, management after CL shortens <10 mm varies. The purpose of this study was to elucidate current practice patterns amongst maternal-fetal medicine (MFM) specialists.

STUDY DESIGN

We conducted an online survey of MFM attending physicians and fellows in the United States from May 2019 to April 2020. The primary outcome was management of varying CL based on gestational age. Variations in management were assessed descriptively.

RESULTS

There were 236 respondents out of 400 eligible surveyed, with a response rate of 59.2%. Universal CL screening was reported by 93.6% (49.6% abdominal and 44.1% transvaginal). Management of short CL varied based on CL measurement, rather than gestational age at presentation. At CL <10 mm, management included cerclage (17.4-18.7%), vaginal progesterone (41.3-41.7%), or cerclage plus vaginal progesterone (43.4%). Between CL of 10 to 20 mm, the majority (77.4-91.9%) would start vaginal progesterone. At CL 21 to 25 mm, management varied between expectant management (45.5-48.5%) or vaginal progesterone (51.1-52.8%). Suture material used was ethylene terephthalate (47.4%) or polypropelene (31.2). Preoperative antibiotic use was reported by 22.3%, while 45.5% used them only if the amniotic membranes were exposed, and 32.2% reported no antibiotic use. Postoperative tocolytic use varied with 19.3% reporting no use, 32.6% using it always, 8.2% only after significant cervical manipulation, 22.7% after the patient is experiencing symptoms, and 17.6% using it only if the cervix is dilated on exam. After cerclage placement, 44.5% continued CL surveillance.

CONCLUSION

Substantial differences of opinion exist among MFM physicians regarding management of incidentally found short CL in patients without history of PTB. The differences in responses obtained highlight the need for evidence-based guidelines for managing this clinical scenario.

KEY POINTS

· There is lack of consensus on the management of incidentally found shortened CL.. · The purpose of this study was to elucidate current trends in CL screening and management.. · Substantial differences of opinion exist regarding management of incidentally found short CL..

Effects of emergency/nonemergency cervical cerclage on the vaginal microbiome of pregnant women with cervical incompetence

Background

Evaluation of the therapeutic effects of cerclage on preterm birth (PTB) caused by cervical incompetence remains challenging. The vaginal microbiome is associated with preterm births. Thus, this study aimed to analyse the vaginal microbiota of patients with cervical incompetence, explore the relationship between the composition of the vaginal microbiota before cervical cerclage and at term delivery, and assess the effect of cervical cerclage on the vaginal microbiota.

Methods

Patients (n = 30) underwent cerclage performed by the same surgical team. Vaginal swabs were obtained pre-surgery and seven days post-surgery. A gestational age-matched cohort of healthy pregnant women (n = 20) (no particular abnormality during pregnancy, delivery at term) was used as the control group and sampled during a comparable pregnancy. All collected vaginal swabs were analysed by 16S rRNA gene sequencing.

Results

When comparing the healthy control and cervical cerclage groups, the enriched microorganism in the healthy controls was G. Scardovia, and the enriched microorganism of the cerclage was G. Streptococcus. α diversity was significantly increased in patients who received cerclage with preterm delivery compared with those with full-term delivery, and the enriched microorganism was F. Enterococcus. A comparison before and after nonemergency cerclage suggested that the enriched microorganisms were G. Lactobacillus and F. Lactobacillaceae before surgery. After nonemergency cerclage, the enriched microorganisms were F. Enterobacteriaceae and C. Gammaproteobacteria. Vaginal microbiota diversity significantly increased, and the proportion of women with Lactobacillus spp.-depleted microbiomes increased after emergency cerclage. Significant differences in β diversity were found between the groups. Before the emergency cerclage, the enriched microorganisms were G. Lactobacillus, O. Alteromonadales, and P. Firmicutes. After emergency cerclage, the enriched microorganisms were P. Actinobacteria, C. Actinobacteria, P. Proteobacteria, F. Bifidobacteriaceae, O. Bifidobacteriales, G. Gardnerella, and G. Veillonella.

Conclusion

Cerclage (particularly emergency cerclage) may alter the vaginal microbiota by increasing microbiota diversity, decreasing vaginal Lactobacillus abundance, and increasing the abundance of pathogenic bacteria that are not conducive to pregnancy maintenance, thereby affecting surgical efficacy. Therefore, the role of the vaginal microbiome should be considered when developing treatment strategies for pregnant women with cervical incompetence.

Clinical trial registration

https://www.chictr.org.cn, identifier ChiCTR2100046305.

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.

Suprapubic-assisted transurethral excision of eroded transvaginal cerclage suture

AIM OF THE VIDEO/INTRODUCTION

The aim was to demonstrate our minimally invasive technique for excision of eroded transvaginal cervical cerclage suture through the bladder mucosa using a suprapubic-assisted transurethral approach. Transvaginal cervical cerclage is a common treatment for cervical insufficiency in pregnancy. Complications such as erosion are rare, as the duration of treatment is typically several months, with cerclage placement in the second trimester and complete removal prior to the onset of labor. Retained suture can lead to erosion through the vaginal epithelium and into other organs, as seen in our case. Our technique offers a minimally invasive approach to the excision of eroded transvaginal cervical cerclage suture through the bladder mucosa.

METHODS

A narrated, stepwise video demonstration for removal of eroded cervical cerclage through bladder epithelium with suprapubic-assisted transurethral technique in a single patient was carried out. Key strategies for a successful outcome include: use of a Carter-Thomason device for suprapubic assistance in lieu of suprapubic trocar or suprapubic incision, use of rigid biopsy forceps for improved traction on the eroded suture, performing a methylene blue test for evaluation of vesicovaginal fistula after excision procedure.

RESULTS

At her 2-week postoperative evaluation, the patient reported resolution of all symptoms. The Carter-Thomason incision was well healed, and postoperative urinalysis was negative for hematuria.

CONCLUSIONS

A suprapubic-assisted transurethral approach can be used as a minimally invasive technique for excision of eroded transvaginal cervical cerclage suture through the bladder mucosa.

Prediction of emergency cerclage outcomes in women with cervical insufficiency: The role of inflammatory, angiogenic, and extracellular matrix-related proteins in amniotic fluid

OBJECTIVE

We aimed to determine whether various novel inflammatory, angiogenic, and extracellular matrix-related mediators in amniotic fluid (AF) can independently predict emergency cerclage outcomes in women with acute cervical insufficiency (CI).

METHODS

This was a retrospective cohort study conducted among 50 singleton pregnant women (18-25 weeks) who underwent emergency cerclage for CI and were subjected to amniocentesis. The AF samples were assayed for endoglin, endostatin, haptoglobin, insulin-like growth factor-binding protein (IGFBP)-3, -4, kallistatin, lumican, macrophage colony-stimulating factor (M-CSF), pentraxin 3, p-selectin, receptor for advanced glycation end products (RAGE), resistin, transforming growth factor beta-induced (TGFBI), and vitamin D-binding protein (VDBP) levels. Interleukin (IL)-6 levels in the AF were also measured for comparison with potential biomarkers assessed in this study. The primary endpoint was spontaneous preterm delivery (SPTD) at <34 weeks following emergency cerclage.

RESULTS

The AF levels of pentraxin 3, RAGE, and resistin were significantly higher in women who had SPTD at <34 weeks after cerclage placement (pentraxin-3: P = 0.003; RAGE: P = 0.041; and resistin; P = 0.002). In multivariate analysis, elevated AF levels of pentraxin 3 (P = 0.007) and resistin (P = 0.006), but not those of RAGE (P = 0.069), were independently associated with the occurrence of SPTD at <34 weeks after cerclage, following adjustment for baseline clinical variables (e.g., cervical dilation). The area under the curve (AUC) values of AF pentraxin 3, RAGE, and resistin for the prediction of SPTD at <34 weeks were 0.749, 0.669, and 0.770, respectively, which were similar to those of AF IL-6. However, in univariate analyses, no differences in the AF levels of endoglin, endostatin, haptoglobin, IGFBP-3, IGFBP-4, kallistatin, lumican, p-selectin, TGFBI, and VDBP were found to be associated with SPTD at <34 weeks after cerclage placement.

CONCLUSIONS

In women with acute CI, the AF levels of pentraxin 3, RAGE, and resistin could be useful novel biomarkers for predicting SPTD following emergency cerclage. However, the clinical utility of these new biomarkers should be validated in larger multicenter studies.

Interventions for the prevention of spontaneous preterm birth: a scoping review of systematic reviews

BACKGROUND

Globally, 11% of babies are born preterm each year. Preterm birth (PTB) is a leading cause of neonatal death and under-five mortality and morbidity, with lifelong sequelae in those who survive. PTB disproportionately impacts low/middle-income countries (LMICs) where the burden is highest.

OBJECTIVES

This scoping review sought to the evidence for interventions that reduce the risk of PTB, focusing on the evidence from LMICs and describing how context is considered in evidence synthesis.

DESIGN

We conducted a scoping review, to describe this wide topic area. We searched five electronic databases (2009-2020) and contacted experts to identify relevant systematic reviews of interventions to reduce the risk of PTB. We included published systematic reviews that examined the effectiveness of interventions and their effect on reducing the risk of PTB. Data were extracted and is described narratively.

RESULTS

139 published systematic reviews were included in the review. Interventions were categorised as primary or secondary. The interventions where the results showed a greater effect size and consistency across review findings included treatment of syphilis and vaginal candidiasis, vitamin D supplementation and cervical cerclage. Included in the 139 reviews were 1372 unique primary source studies. 28% primary studies were undertaken in LMIC contexts and only 4.5% undertaken in a low-income country (LIC) Only 10.8% of the reviews sought to explore the impact of context on findings, and 19.4% reviews did not report the settings or the primary studies.

CONCLUSION

This scoping review highlights the lack of research evidence derived from contexts where the burden of PTB globally is greatest. The lack of rigour in addressing contextual applicability within systematic review methods is also highlighted. This presents a risk of inappropriate and unsafe recommendations for practice within these contexts. It also highlights a need for primary research, developing and testing interventions in LIC settings.

Interventions to prevent preterm delivery in women with short cervix before fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVE

Preoperative short cervical length (CL) remains a major risk factor for preterm birth after laser surgery for twin-twin transfusion syndrome (TTTS), but the optimal intervention to prolong pregnancy remains elusive. The objective of this study was to compare secondary methods for the prevention of preterm birth in twin pregnancies with TTTS undergoing fetoscopic laser photocoagulation (FLP), in the setting of a short cervix at the time of FLP, in five North American Fetal Treatment Network (NAFTNet) centers.

METHODS

This was a secondary analysis of data collected prospectively at five NAFTNet centers, conducted from January 2013 to March 2020. Inclusion criteria were a monochorionic diamniotic twin pregnancy complicated by TTTS, undergoing FLP, with preoperative CL < 30 mm. Management options for a short cervix included expectant management, vaginal progesterone, pessary (Arabin, incontinence or Bioteque cup), cervical cerclage or a combination of two or more treatments. Patients were not included if the intervention was initiated solely on the basis of having a twin gestation rather than at the diagnosis of a short cervix. Demographics, ultrasound characteristics, operative data and outcomes were compared. The primary outcome was FLP-to-delivery interval. Propensity-score matching was performed, with each treatment group matched (1:1) to the expectant-management group for CL, in order to estimate the effect of each treatment on the FLP-to-delivery interval.

RESULTS

A total of 255 women with a twin pregnancy complicated by TTTS and a short cervix undergoing FLP were included in the study. Of these, 151 (59%) were managed expectantly, 32 (13%) had vaginal progesterone only, 21 (8%) had pessary only, 21 (8%) had cervical cerclage only and 30 (12%) had a combination of treatments. A greater proportion of patients in the combined-treatment group had had a prior preterm birth compared with those in the expectant-management group (33% vs 9%; P = 0.01). Mean preoperative CL was shorter in the pessary, cervical-cerclage and combined-treatment groups (14-16 mm) than in the expectant-management and vaginal-progesterone groups (22 mm for both) (P < 0.001). There was no significant difference in FLP-to-delivery interval between the groups, nor in gestational age at delivery or the rate of live birth or neonatal survival. Vaginal progesterone was associated with a decrease in the risk of delivery before 28 weeks' gestation compared with cervical cerclage and combined treatment (P = 0.03). Using propensity-score matching for CL, cervical cerclage was associated with a reduction in FLP-to-delivery interval of 13 days, as compared with expectant management.

CONCLUSIONS

A large proportion of pregnancies with TTTS and a short maternal cervix undergoing FLP were managed expectantly for a short cervix, establishing a high (62%) risk of delivery before 32 weeks in this condition. No treatment that significantly improved outcome was identified; however, there were significant differences in potential confounders and there were also likely to be unmeasured confounders. Cervical cerclage should not be offered as a secondary prevention for preterm birth in twin pregnancies with TTTS and a short cervix undergoing FLP. A large randomized controlled trial is urgently needed to determine the effects of treatments for the prevention of preterm birth in these pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Frequency of cerclage in consecutive pregnancies of women with history of preterm birth

BACKGROUND

Serial cervical length screening is performed in women with a history of preterm birth to determine indication for cerclage placement. Our aim is to evaluate the frequency of cerclage placement in consecutive pregnancies with preterm birth history to determine whether performing serial cervical length screening for women with a history of late (34-36 6/7 weeks) spontaneous preterm birth (SPTB) should be reconsidered.

METHODS

Retrospective evaluation of cerclage frequency and gestational age of delivery for consecutive singleton births for 69,671 women whose first birth was a SPTB.

RESULTS

History of late SPTB was associated with a lower frequency of cerclage than history of early SPTB (0.83% vs 4.88%, OR 0.16, 95% CI 0.14-0.18). Rates of recurrent SPTB were lower for women with history of late SPTB than those with history of early SPTB (13.45%, 3.74% early, 9.71% late vs 20.69%, 9.12% early, 11.57% late).

CONCLUSION

Women with a history of late PTB have a lower risk of recurrent PTB than those with a history of early PTB but constitute most of those undergoing serial cervical length screening for potential cerclage placement. Practice guidelines for screening women with a history of late PTB should be re-evaluated.

Prophylactic Cerclage to Prevent Preterm Birth after Conization: A Cohort Study Using Data from the National Health Insurance Service of Korea

PURPOSE

To investigate potential differences in the frequency of preterm births (PTB) between pregnancies with or without prophylactic cerclage in women with a history of conization.

MATERIALS AND METHODS

We identified women who had their first singleton delivery after conization between 2013 and 2018 using records in the National Health Insurance Service of Korea claims database. We only included women who had undergone a health examination and interview within 2 years before delivery. We used timing of maternal serum alpha-fetoprotein (MSAFP) tests to differentiate early (before) from late (after the MSAFP test) cerclage. The frequency of adverse pregnancy outcomes, including PTB, preterm labor and premature rupture of membranes, antibiotics and tocolytics use, cesarean delivery, and number of admissions before delivery, were compared.

RESULTS

A total of 8322 women was included. Compared to the no cerclage group (n=7147), the risks of adverse pregnancy outcomes were higher in the cerclage group (n=1175). After categorizing patients with cerclage into two groups, the risk of PTB was still higher in the early cerclage group than in the no cerclage group after adjusting for baseline factors (4.48%, 30/669 vs. 2.77%, 159/5749, odds ratio 2.42, 95% confidence interval 1.49, 3.92). Other adverse pregnancy outcomes were also more frequent in the early cerclage group than the no cerclage group.

CONCLUSION

Early cerclage performed before MSAFP testing does not prevent PTB in pregnancy with a history of conization, but increases the risk of adverse pregnancy outcomes, including PTB.

OBGYN practice patterns regarding combination therapy for prevention of preterm birth: A national survey

OBJECTIVE

Our objective was to examine if US obstetrician-gynecologists (OBGYNs) practice outside of evidenced-based guidelines and use a combination of interventions to prevent spontaneous preterm birth (sPTB).

STUDY DESIGN

An electronic survey was distributed to members of the Pregnancy-Related Care Research Network (PRCRN), and also to members of the Society of Maternal-Fetal Medicine (SMFM). The survey consisted of questions regarding physician demographics, and the use of interventions to prevent sPTB in women with 1) a prior sPTB, 2) an incidental short cervix (no prior sPTB), and 3) a history of cervical insufficiency.

RESULTS

The PRCRN response rate was 58.6% (283/483) with an additional 143 responses from SMFM members. Among PRCRN responders, 82.7% were general OBGYNs and 17.3% were Maternal-Fetal Medicine subspecialists. Respondents were from all geographic regions of the country; most practiced in a group private practice (42.6%) or academic institution (31.4%). In women with prior sPTB, 45.2% of respondents would consider combination therapy, most commonly weekly intramuscular progesterone (IM-P) and serial cervical length (CL) measurements. If the patient then develops a short cervix, 33.7% would consider adding an ultrasound-indicated cerclage. In women with an incidental short cervix, 66.8% of respondents were likely to recommend single therapy with daily vaginal progesterone (VP). If a patient developed an incidentally dilated cervix, 40.8% of PRCRN respondents would recommend dual therapy, most commonly cerclage + VP, whereas 64.3% of SMFM respondents were likely to continue with VP only. In women with a history of cervical insufficiency, 47% of PRCRN respondents indicated they would consider a combination of IM-P, history-indicated cerclage and serial CL measurements.

CONCLUSION

Although not currently supported by evidence-based medicine, combination therapy is commonly being used by U.S. OBGYNs to prevent sPTB in women with risk factors such as prior sPTB, short or dilated cervix or more than one of these risks.