Cerclage for short cervix in twin pregnancies: systematic review and meta-analysis of randomized trials using individual patient-level data

Pregnancy outcomes of cerclage in twin gestations: a multicenter retrospective cohort study

OBJECTIVES

To determine the effects of cerclage on twin pregnancies.

METHODS

A multicenter, retrospective, cohort study was conducted at 10 tertiary centers using a web-based data collection platform. The study population included twin pregnancies delivered after 20 weeks of gestation. Patients with one or two fetal deaths before 20 weeks of gestation were excluded. Maternal characteristics, including prenatal cervical length (CL) and obstetric outcomes, were retrieved from the electronic medical records.

RESULTS

A total of 1,473 patients had available data regarding the CL measured before 24 weeks of gestation. Seven patients without CL data obtained prior to cerclage were excluded from the analysis. The study population was divided into two groups according to the CL measured during the mid-trimester: the CL ≤2.5 cm group (n = 127) and the CL >2.5 cm group (n = 1,339). A total of 127 patients (8.7%) were included in the CL ≤2.5 cm group, including 41.7% (53/127) who received cerclage. Patients in the CL >2.5 cm group who received cerclage had significantly lower gestational age at delivery than the control group (hazard ratio (HR): 1.8; 95% confidence interval (CI): 1.11-2.87; p = .016). Patients in the CL ≤2.5 cm group who received cerclage had a significantly higher gestational age at delivery than the control group (HR: 0.5; 95% CI: 0.30-0.82; p value = .006).

CONCLUSIONS

In twin pregnancies with a CL ≤2.5 cm, cerclage significantly prolongs gestation. However, unnecessary cerclage in women with a CL >2.5 cm may result in a higher risk of preterm labor and histologic chorioamnionitis although this study has a limitation originated from retrospective design.

Prevention of preterm birth in twin-to-twin transfusion syndrome: a systematic review and network meta-analysis

OBJECTIVES

We aimed to perform a systematic review and network meta-analysis to evaluate the preventive strategies for preterm birth in twin-to-twin transfusion syndrome.

METHODS

PubMed, Embase and Cochrane Central were searched from inception to December 2023 with no filters. Additionally, the reference lists of the included studies were manually examined to identify any supplementary studies. We selected randomized controlled trials and cohorts comparing interventions to prevent preterm birth in twin pregnancies complicated by twin-to-twin transfusion syndrome. A random-effects frequentist network meta-analysis was performed using RStudio version 4.3.1. Randomized controlled trials and cohorts were assessed respectively using the Risk of Bias in Non-randomized Studies of interventions tool and Cochrane Collaboration's tool for assessing risk of bias in randomized trials.

RESULTS

In this systematic review and meta-analysis, we included eight studies comprising a total of 719 patients. Compared with expectant management, cerclage stood out as the only intervention associated with an increase in the survival of at least one twin (risk ratio 1.12; 95 % confidence interval 1.01-1.23). Our subgroup analysis based on different thresholds for short cervix demonstrated a significant reduction in the risk of preterm birth before 32 weeks with ultrasound-indicated cerclage using a 15 mm criterion (risk ratio 0.65; 95 % confidence interval 0.47-0.92).

CONCLUSIONS

Our study suggests the potential benefit of cerclage as a preventive strategy for preterm birth in pregnancies complicated by twin-to-twin transfusion syndrome. These findings highlight the necessity for further investigation to corroborate our results and address the optimal threshold for ultrasound-indicated cerclage.

SMFM Consult Series #70: Management of short cervix in individuals without a history of spontaneous preterm birth

Most deliveries before 34 weeks of gestation occur in individuals with no previous history of preterm birth. Midtrimester cervical length assessment using transvaginal ultrasound is one of the best clinical predictors of spontaneous preterm birth. This Consult provides guidance for the diagnosis and management of a short cervix in an individual without a history of preterm birth. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend that all cervical length measurements used to guide therapeutic recommendations be performed using a transvaginal approach and in accordance with standardized procedures as described by organizations such as the Perinatal Quality Foundation or the Fetal Medicine Foundation (GRADE 1C); (2) we recommend using a midtrimester cervical length of ≤25 mm to diagnose a short cervix in individuals with a singleton gestation and no previous history of spontaneous preterm birth (GRADE 1C); (3) we recommend that asymptomatic individuals with a singleton gestation and a transvaginal cervical length of ≤20 mm diagnosed before 24 weeks of gestation be prescribed vaginal progesterone to reduce the risk of preterm birth (GRADE 1A); (4) we recommend that treatment with vaginal progesterone be considered at a cervical length of 21 to 25 mm based on shared decision-making (GRADE 1B); (5) we recommend that 17-alpha hydroxyprogesterone caproate, including compounded formulations, not be prescribed for the treatment of a short cervix (GRADE 1B); (6) in individuals without a history of preterm birth who have a sonographic short cervix (10-25 mm), we recommend against cerclage placement in the absence of cervical dilation (GRADE 1B); (7) we recommend that cervical pessary not be placed for the prevention of preterm birth in individuals with a singleton gestation and a short cervix (GRADE 1B); and (8) we recommend against routine use of progesterone, pessary, or cerclage for the treatment of cervical shortening in twin gestations outside the context of a clinical trial (GRADE 1B).

Development and validation of a nomogram for individualized prediction of spontaneous extremely preterm birth at < 28 weeks in twin pregnancy: a retrospective cohort study

PURPOSE

To develop a nomogram to predict spontaneous preterm birth at < 28 weeks in pregnant women with twin pregnancies.

METHODS

We retrospectively studied the medical records of twin-pregnancy women with asymptomatic cervical dilation or cervical shortening between December 2015 to February 2022 in two hospitals. Data from one center was used to develop the model and data from the other was used to evaluate the model.

RESULTS

A total of 270 twin pregnancies were enrolled in the study. We incorporated 4 items (cervical length, cervical dilation, C-reactive protein and the use of cerclage) to build the 28-week nomogram with satisfactory discrimination and calibration when applied to the validation sets. The C index for the 28-week nomogram in the development and external cohort was 0.88 (95% CI, 0.84-0.93) and 0.89 (95% CI, 0.80-0.98), respectively. The nomogram reached a sensitivity of 70.70%, specificity of 97.10%, positive predicted value of 95.61% and negative predicted value of 78.77%. Moreover, the decision curve analysis indicated that the nomogram showed positive clinical benefit.

CONCLUSION

We developed and validated a nomogram with good performance in predicting individual risk of spontaneous preterm birth at < 28 in twin pregnancy.

Effectiveness and pregnancy outcomes of ultrasound-indicated and physical examination-indicated cervical cerclage: a retrospective study from a single centre

OBJECTIVE

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality worldwide, and cervical incompetence (CIC) is a significant contribution. Cervical cerclage (CC) is an effective obstetric intervention. However, many clinical factors affect the success rate of surgery. The objective was to investigate and compare the pregnancy and neonatal outcomes of patients who underwent ultrasound- and physical examination-indicated cervical cerclage and to explore the influencing factors of preterm delivery before 34 weeks.

METHODS

The sociodemographic characteristics and clinical data of patients with a diagnosis of cervical incompetence who underwent ultrasound- and physical examination-indicated transvaginal cervical cerclage at Nanjing Maternal and Child Health Hospital from January 2020 to December 2022 were retrospectively analyzed. The pregnancy and neonatal outcomes of the patients were evaluated. Continuous variables were compared using Student's t test (for normally distributed data) or the Mann-Whitney U test (for nonnormally distributed data). Categorical variables were analysed using the chi-square test or Fisher's exact test. Additionally, logistic regression analyses and receiver operating characteristic curves were used to evaluate the associations of inflammatory markers with maternal and neonatal outcomes.

RESULTS

This study included 141 participants who underwent cervical cerclage, including 71 with ultrasound-indicated cerclage and 70 with physical examination-indicated cerclage. Compared to those in the ultrasound-indicated cerclage group, the duration from cerclage to delivery, birth weight, and APGAR score in the physical examination-indicated cerclage group were significantly lower, and the rates of delivery at < 28 weeks, < 32 weeks, < 34 weeks, and < 37 weeks of gestation and neonatal mortality were significantly higher (all P < 0.05). Compared to those in the physical ultrasound-indicated cerclage group, in the physical examination-indicated cerclage group, maternal blood inflammatory markers, such as C-reactive protein (CRP), the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI) were significantly higher (P < 0.05). Additionally, maternal blood inflammatory markers, such as the CRP, white blood cell count, platelet to lymphocyte ratio (PLR), SII, and SIRI were significantly higher in the group with delivery before 34 weeks of gestation. Furthermore, the results demonstrated that twin pregnancy had the highest OR for preterm delivery before 34 weeks of gestation (OR = 3.829; 95% CI 1.413-10.373; P = 0.008), as well as the following: the SII level (OR = 1.001; 95% CI 1.000-1.002; P = 0.003) and CRP level (OR = 1.083; 95% CI 1.038-1.131; P = 0.022). The risk factors for preterm delivery before 34 weeks of gestation were twin gestation, an increased SII level and an increased CRP level, which had good combined predictive value.

CONCLUSION

In patients with cervical insufficiency, ultrasound-indicated cervical cerclage appears to lead to better pregnancy outcomes than physical examination-indicated cerclage. Twin pregnancy and maternal blood inflammatory markers, such as the CRP level and the SII, are associated with preterm delivery before 34 weeks of gestation.

Cervical elastography using E-Cervix™ for prediction of preterm birth in twin pregnancies with threatened preterm labor

OBJECTIVE

To evaluate the prediction performance of E-Cervix™ for preterm birth in twin pregnancies with threatened preterm labor.

METHODS

This was a single-center retrospective cohort study of twin pregnancies presenting to obstetrics triage for threatened preterm labor (PTL) between 23 0/7 - 33 6/7 weeks who received screening for PTL with transvaginal ultrasound cervical length (TVU CL) and cervical elastography with E-Cervix™ at the time of triage. Cervical elastography parameters were examined and compared between women who delivered preterm and those who did not. The quantification of cervical strain was calculated by a data analysis system that directly analyzes raw data from the region of interest (ROI) and described as hardness ratio (HR), mean strain level within 1 cm from internal (IOS) and external (EOS) os.

RESULTS

63 twin gestations without prior preterm birth and with threatened PTL between 23 0/7 - 33 6/7 weeks of gestation were included in the study. 27 (42.9 %) had cervical length < 25 mm, and were admitted for true PLT. Out of the 36 women with cervical length ≥ 25 mm, 6 (16.7 %) were admitted. Women with threatened PTL had significantly higher HR compared to those with true PTL (p < 0.01), and significantly lower IOS and EOS. Women who delivered preterm had significantly higher HR compared to those who did not delivery preterm and significantly lower IOS and EOS, in overall cohort, and in the subset of women with true PTL. Incidences of HR < 50 % and < 35 % were statistically significantly higher in women who delivered preterm compared to those who did not (p < 0.01).

CONCLUSION

Cervical elastography with E-Cervix™ may be useful for assessment of twin gestations presenting to obstetrics triage for threatened PTL.

Study protocol for two randomised controlled trials evaluating the effects of Cerclage in the reduction of extreme preterm birth and perinatal mortality in twin pregnancies with a short cervix or dilatation: the TWIN Cerclage studies

INTRODUCTION

Twin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently there is a lack of effective treatments for women with a twin pregnancy and a short cervix or cervical dilatation. A possible effective surgical method to reduce extreme PTB in twin pregnancies with an asymptomatic short cervix or dilatation at midpregnancy is the placement of a vaginal cerclage.

METHODS AND ANALYSIS

We designed two multicentre randomised trials involving eight hospitals in the Netherlands (sites in other countries may be added at a later date). Women older than 16 years with a twin pregnancy at <24 weeks of gestation and an asymptomatic short cervix of ≤25 mm or cervical dilatation will be randomly allocated (1:1) to both trials on vaginal cerclage and standard treatment according to the current Dutch Society of Obstetrics and Gynaecology guideline (no cerclage). Permuted blocks sized 2 and 4 will be used to minimise the risk of disbalance. The primary outcome measure is PTB of <28 weeks. Analyses will be by intention to treat. The first trial is to demonstrate a risk reduction from 25% to 10% in the short cervix group, for which 194 patients need to be recruited. The second trial is to demonstrate a risk reduction from 80% to 35% in the dilatation group and will recruit 44 women. A cost-effectiveness analysis will be performed from a societal perspective.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committees in the Netherlands on 3/30/2023. Participants will be required to sign an informed consent form. The results will be presented at conferences and published in a peer-reviewed journal. Participants will be informed about the results.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05968794.

PROMPT: Prospective Meta-analysis for Pessary Trials Study Protocol

OBJECTIVE

Preterm birth, defined as birth before 37 weeks of gestation, is a leading cause of perinatal and infant mortality throughout the world. Preterm birth is also associated with long-term neurological disabilities and other significant health issues in children. A short cervix in the second trimester has been noted to be one of the strongest predictors of subsequent spontaneous preterm birth in both singleton and multiple pregnancies. Some studies have shown that cervical support in the form of an Arabin pessary lowers the risk of preterm birth in women with a singleton gestation and short cervical length; however, other studies have conflicting results. Our objective was to form an international collaborative of planned or ongoing randomized trials of pessary in singleton and twin gestations with a short cervix.

STUDY DESIGN

In November 2014, an international group of investigators, who had initiated or were planning randomized trials of pessary for pregnant people with a short cervix and singleton or twin gestation to prevent preterm birth, formed a collaboration to plan a prospective individual patient data (IPD) meta-analysis of randomized trials (PROspective Meta-analysis of Pessary Trials [PROMPT]). The PROMPT investigators agreed on meta-analysis IPD hypotheses for singletons and twins, eligibility criteria, and a set of core baseline and outcome measures. The primary outcome is a composite of fetal death or preterm delivery before 32 weeks' gestation. Secondary outcomes include maternal and neonatal morbidities. The PROMPT protocol may be viewed as a written agreement among the study investigators who make up the PROMPT consortium (PROSPERO ID# CRD42018067740).

RESULTS

Results will be published in phases as the individual participating studies are concluded and published. Results of the first phase of singleton and twin pessary trials are expected to be available in late 2022. Updates are planned as participating trials are completed and published.

KEY POINTS

· Short cervical length predicts preterm birth.. · Results of prior cervical pessary trials are mixed.. · Meta-analysis of pessary trials protocol..

Maternal positional therapy for fetal growth and customised birth weight centile benefit in a Bayesian reanalysis of a double-blind, sham-controlled, randomised clinical trial

OBJECTIVES

To update the Ghana PrenaBelt Trial's (GPT) primary outcome data with the latest fetal growth standard and reanalyse it. To estimate the posterior probability, under various clinically relevant prior probabilities, of maternal nightly positional therapy (PT) throughout the third-trimester having a beneficial effect on customised birth weight centile (CBWC) using Bayesian analyses.

DESIGN

A reanalysis of a double-blind, sham-controlled, randomised clinical trial.

SETTING

A single, tertiary-level centre in Accra, Ghana.

PARTICIPANTS

Two-hundred participants entered, 181 completed and 167 were included in the final analysis. Participants were Ghanaian, healthy, aged 18-35 years, with low-risk, singleton pregnancies in their third-trimester, with Body Mass Index<35 kg/m2 at the first antenatal appointment for the index pregnancy and without known fetal abnormalities, pregnancy complications or medical conditions complicating sleep.

INTERVENTIONS

Participants were randomised to receive treatment with either a PT or sham-PT device.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the CBWC using the latest Perinatal Institute, Gestation-Related Optimal Weight calculator. Using Bayesian methods, posterior probabilities of achieving a greater than 0%, 5% and 10% benefit in CBWC with PT were estimated. There was no secondary outcome.

RESULTS

The median (IQR) CBWC was 42% (15-71) and 28% (9-52) in the PT and sham-PT groups, respectively (difference 8.4%; 95% CI -0.30 to 18.2; p=0.06). For achieving a >0%, >5% and >10% gain in CBWC with PT, the posterior probabilities were highly probable, probable and unlikely, respectively, given a range of prior probabilities reflecting varying degrees of pre-existing enthusiasm and scepticism.

CONCLUSIONS

Maternal nightly PT throughout the third-trimester did not have a statistically significant effect on CBWC on a frequentist analysis using the latest fetal growth standard. However, from a Bayesian analysis, clinicians can infer that PT is likely to benefit fetal growth but with a modest effect size.

TRIAL REGISTRATION NUMBER

NCT02379728.

Randomized controlled trials: not always the "gold standard" for evidence in obstetrics and gynecology

Randomized controlled trials are considered the "gold standard" for therapeutic interventions, and it is not uncommon for sweeping changes in medical practice to follow positive results from such trials. However, randomized controlled trials are not without their limitations. Physicians frequently view randomized controlled trials as infallible, whereas they tend to dismiss evidence derived from sources other than randomized controlled trials as less credible or reliable. In several situations in obstetrics and gynecology, there are no randomized controlled trials to help guide the clinician. In these circumstances, it is important to evaluate the entire body of evidence including observational studies, rather than dismiss interventions altogether simply because no randomized controlled trials exist. Randomized controlled trials and observational studies should be viewed as complementary rather than at odds with each other. Some reversals in widely adopted clinical practice have recently been implemented following subsequent studies that contradicted the outcomes of major randomized controlled trials. The most notable of these was the withdrawal from the market of 17-hydroxyprogesterone caproate for preterm birth prevention. Such reversals could potentially have been averted if the inherent limitations of randomized controlled trials were carefully considered before implementing these universal practice changes. This Clinical Opinion underscores the limitations of an exclusive reliance on randomized controlled trials while disregarding other evidence in determining how best to care for patients. Solutions are proposed that advocate that clinicians adopt a more balanced perspective that considers the entirety of the available medical evidence and the individual patient characteristics, needs, and wishes.

The effectiveness of cervical cerclage in twin pregnancies with a mid-trimester short cervix: A retrospective cohort study

OBJECTIVE

To analyze the effectiveness of cerclage in twin pregnancies with a short cervix.

STUDY DESIGN

Retrospective cohort study performed in two University Institutions in Valencia (Spain) with two different protocols for the management of asymptomatic dichorionic diamniotic twin pregnancies with mid-trimester cervical length ≤ 25 mm: treatment with indomethacin, antibiotics and cerclage (cerclage group) (N = 43) versus expectant management (control group) (N = 37).

RESULTS

The initial cervical length was similar in both groups but detection of a short cervix was performed earlier in the cerclage group (21.6 vs 24.1 weeks, p < 0.001). Women with cerclage had a greater pregnancy latency (12.5 vs. 7.7 weeks, p < 0.001); higher gestational age at delivery (34.1 vs. 31.8 weeks, p < 0.04); less spontaneous preterm birth (SPB) < 28 weeks (11.6 % vs 37.8 %, p < 0.009); higher birthweight (2145 vs 1733 g, p < 0.001); lower birthweight < 1500 g (12.5 % vs 40.0 %, p < 0.001); less admissions to the neonatal intensive care unit (NICU) (24.1 % vs 43.3 %, p < 0.03); shorter stay at NICU (25.6 vs 49.4 days, p < 0.02); lower respiratory distress requiring mechanical ventilation (14.9 % vs 36.5 %, p < 0.02); fewer patent ductus arteriosus (8.9 % vs 26.9 %, p < 0.008); and lower composite adverse neonatal outcome (26.6 % vs. 44.8 %, p < 0.03). Cerclage and gestational age at diagnosis were the only independent predictors of SPB < 32 and < 28 weeks by multivariate analysis. The cumulative data in the literature show promising beneficial effects of cerclage.

CONCLUSION

Our data suggest that cerclage in asymptomatic twin pregnancies with a short cervix may reduce the earliest SPB and may improve neonatal outcome.

Physical Examination-Indicated Cerclage in Singleton and Twin Pregnancies and Risk Factors for Predicting Preterm Birth < 28 Weeks

We compare the outcomes of physical examination-indicated cerclage (PEIC) between singleton and twin pregnancies and analyze predictive factors for preterm birth < 28 weeks of gestation. Patients who underwent PEIC at our center were reviewed. We compared perinatal outcomes between singleton and twin pregnancies. The primary outcome was delivery before 28 weeks of gestation. Also, we analyzed perioperative clinical, laboratory, and sonographic findings to determine the risk factors for predicting preterm birth < 28 weeks. The rate of preterm birth < 28 weeks was not significantly different. Also, neonatal outcomes were not different. Also, we compared the outcomes according to GA (gestational age) at delivery before (Group A) or after (Group B) 28 weeks, which is the primary outcome. In perioperative findings, group A was likely to have more advanced cervical dilatation, bulging membranes into the vagina, positive fFN or IGFBP-1, and shorter postoperative CL (cervical length) than group B. Also, positive fFN or IGFBP-1 and postoperative CL < 21.6 mm were independently associated with a higher risk of preterm birth < 28 weeks. These findings provide the effectiveness of PEIC with twin pregnancy as well as singleton pregnancy and helpful predictive methods that might effectively identify women at high risk of preterm birth < 28 weeks following PEIC.

Screening and Prevention of Preterm Birth in Twin Pregnancies

Twins represent 3.2% of all live births. However, they account for 20% of all preterm deliveries, 60% delivering <37 weeks, 10.7% <32 weeks, and 5 times higher risk of infant death. Risk factors for preterm birth (PTB) include the history of preterm delivery, monochorionic twins, short cervical length, and cervical surgery. Transvaginal cervical length <24 weeks is the best tool to predict PTB. Only vaginal progesterone in women with transvaginal cervical length <25 mm and physical exam indicated cerclage in women with cervical dilation >1 cm have shown a significant decrease in PTB and improvement in neonatal outcomes.

The use of cervical cerclage in asymptomatic twin pregnancies with cervical shortening or dilation: a twelve-year retrospective cohort study

BACKGROUND

To identify the effect and optimal time of cervical cerclage in asymptomatic twin pregnancies with cervical shortening or dilation.

METHODS

This observational retrospective study enrolled all women with asymptomatic twin pregnancies who were diagnosed with asymptomatic cervical shortening or dilation at the Second Affiliated Hospital of Wenzhou Medical University between 2010 and 2022. Women included were allocated into the cerclage group (n = 36) and the no cerclage group (n = 22). The cerclage group was further divided into the cerclage group (< 24 weeks group) and the cerclage group (24-28 weeks group) according to the time of cerclage. The no cerclage group was further divided into no cerclage group (< 24 weeks group) and no cerclage group (24-28 weeks group) according to the time of ultrasound-indicated or physical exam indicated cerclage. The rates of PTB < 24, 28, 32 and 34 weeks of gestation, maternal and neonatal outcomes were compared among the groups.

RESULTS

The gestational age (GA) at delivery was higher (P = 0.005) and the interval time between the presentation of the indicated cerclage and delivery was longer in the cerclage group (P < 0.001). The rates of PTB before 28, 32, and 34 weeks of gestation, caesarean section and stillbirth were lower in the cerclage group (P < 0.05). The birthweight of the twins was higher in the cerclage group (P = 0.012). Admissions to the NICU were more frequent in pregnancies with no cerclage (P = 0.008). Subgroup analysis showed that the interval time between the presentation and delivery was longer in the cerclage group (< 24 weeks) (P < 0.001). The GA at delivery and the birthweight of the twins were significantly higher in the cerclage group (< 24 weeks) (P < 0.001). No differences were found in the GA at presentation, the GA at delivery, the interval time between the presentation to delivery and birthweight between the cerclage group (24-28 weeks group) and the control group (24-28 weeks group) (P > 0.05).

CONCLUSIONS

Cerclage appears to prolong the GA at delivery and the interval time between the presentation to delivery, and may reduce the incidence of PTB before 28, 32 and 34 weeks of gestation and adverse perinatal outcomes in asymptomatic twin pregnancies with cervical shortening or dilation. Cerclage before 24 weeks of gestation showed longer GA at delivery, longer interval time between the presentation to delivery and higher birthweight of the twins. The GA at presentation, the GA at delivery, the interval time between the presentation to delivery and birthweight in women with cerclage at 24-28 weeks were similar to those in women without cerclage at 24-28 weeks.

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.

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.

Median effective dose of ropivacaine for prophylactic cervical cerclage in Chinese women: a dose-finding study

BACKGROUND

Although intrathecal ropivacaine has been widely used for caesarean delivery, there are limited data for the use of ropivacaine for prophylactic cervical cerclage. We sought to determine the median effective dose of intrathecal ropivacaine for prophylactic cervical cerclage in 50% of patients (ED50) and the calculated dose required for successful block in 95% of patients (ED95).

METHODS

We included Chinese women scheduled for prophylactic cervical cerclage under combined spinal-epidural (CSE) anaesthesia in the first or second trimester. A predetermined dose of intrathecal isobaric ropivacaine was administered. If this determined dose achieved an effective block at a level not lower than T12, the next dose was decreased by 0.5 mg. Otherwise, the next dose was increased by 0.5 mg. The primary outcome was the ED50 of intrathecal ropivacaine. Secondary outcomes included the calculated ED95, time from CSE to the start of surgery and so on.

RESULTS

Forty patients were included in the study, 23 (57.5%) of 40 received an effective block only with intrathecal ropivacaine, while 17 (42.5%) patients needed extra epidural lidocaine to achieve a successful block. The ED50 of intrathecal ropivacaine confirmed by isotonic regression was 6.9 mg (95% CI, 6.68 to 7.12 mg), and the calculated ED95 was 7.8 mg (95% CI, 7.69 to 10.05 mg). When an effective block was achieved with intrathecal ropivacaine alone, the time to resolution of the sensory and motor blocks was 90 (75-100) min and 90 (60-100) min, respectively.

CONCLUSIONS

The ED50 of intrathecal ropivacaine for prophylactic cervical cerclage was 6.9 mg. Intrathecal ropivacaine (7.8 mg) is likely to produce successful anaesthesia in 95% of patients undergoing prophylactic cervical cerclage.

TRIAL REGISTRATION NUMBER

ChiCTR2100051418.

Efficacy of ultrasound-indicated cerclage in twin pregnancies: a retrospective case-control study matched by cervical length

BACKGROUND

Twin pregnancies with a progressively shortening cervix in the midterm pregnancy have an increasing risk for spontaneous preterm birth. Currently, there is no known effective method to prevent preterm birth among those women, and the use of an ultrasound-indicated cerclage in twin pregnancies is still controversial.

OBJECTIVE

This study aimed to estimate whether a combination of ultrasound-indicated cerclage, indomethacin, and antibiotics in twin pregnancies between 18 and 26 weeks' gestation could extend the pregnancy, reduce the risk for spontaneous preterm birth, and improve perinatal and neonatal outcomes.

STUDY DESIGN

A retrospective cohort study was conducted. The ultrasound-indicated cerclage group included twin pregnancies with a transvaginal cervical length <25 mm that underwent cerclage at 18 to 26 weeks of gestation in the Women's Hospital, Zhejiang University School of Medicine, from December 2015 through August 2021. Twin pregnancies in our study that underwent cerclage also received antibiotics and indomethacin. A control group of twin pregnancies that were managed expectantly were matched with the treatment group in terms of transvaginal cervical length at diagnosis (±3 mm), gestational age at presentation of diagnosis (±3 weeks), and maternal age (±5 years). An additional subanalysis was performed in which the patients were divided into 2 subgroups based on transvaginal cervical length of either <15 mm or between 15 and 24 mm. The primary outcome was gestational age at delivery. The secondary outcomes were pregnancy latency, the rate of spontaneous preterm birth at <28, <32, <34, <36 weeks' gestation, and neonatal outcomes.

RESULTS

A total of 90 twin pregnancies with a transvaginal cervical length <25 mm were managed with either a cerclage (ultrasound-indicated cerclage group, n=45) or expectantly (control group, n=45). Demographic characteristics were not significantly different between the groups. When compared with the control group, the gestational age at delivery was significantly higher (33.11±3.16 vs 30.22±4.12 weeks; P=.001) and the pregnancy latency was significantly longer (72.40±22.51 vs 45.56±28.82 days; P<.001) in the ultrasound-indicated cerclage group. The rates of spontaneous preterm birth at <28, <32, <34, and <36 weeks' gestation were significantly lower in the ultrasound-indicated cerclage group than in the control group. In terms of neonatal outcomes, there were significant reductions in the overall perinatal mortality (4.4% vs 20.0%; P<.001), neonatal intensive care unit admissions (69.0% vs 92.6%; P<.001), and composite adverse neonatal outcomes (43.7% vs 64.7%; P=.010) for the ultrasound-indicated cerclage group when compared with the control group. In the subgroup of women with a transvaginal cervical length of between 15 and 24 mm (with 21 in the ultrasound-indicated cerclage group vs 21 controls), the data were adjusted for maternal age, pregestational body mass index, in vitro fertilization, operative hysteroscopy, previous cervical surgery, previous spontaneous preterm birth, white blood cell counts, C-reactive protein level, neutrophil to lymphocyte ratio, and the shortest transvaginal cervical length measured at diagnosis. In ultrasound-indicated cerclage group, gestational age at delivery was significantly higher (32.95±3.81 vs 30.24±4.01 weeks; beta, 3.34; 95% confidence interval, 0.14-6.55; P=.042), pregnancy latency was significantly prolonged (77.19±24.81 vs 48.52±29.67 days; beta, 33.81; 95% confidence interval, 12.29-55.34; P=.003), and the rates of spontaneous preterm birth <36 weeks' gestation (57.1% vs 95.2%; adjusted odds ratio, 0.03; 95% confidence interval, 0.01-0.69; P=.029) was significantly decreased, and for neonatal outcomes, there were significant reductions in neonatal intensive care unit admissions (53.7% vs 96.7%; adjusted odds ratio, 0.04; 95% confidence interval, 0.01-0.32; P=.003) and the composite adverse neonatal outcomes (39.0% vs 73.3%; adjusted odds ratio, 0.24; 95% confidence interval, 0.08-0.68; P=.008) in the ultrasound-indicated cerclage group when compared with the control group. In the subgroup of women with a transvaginal cervical length <15 mm, gestational age at delivery was higher (33.25±2.52 vs 30.00±4.33 weeks; beta, 3.96; 95% confidence interval, 1.51-6.42; P=.002), pregnancy latency was significantly prolonged (68.21±19.85 vs 42.96±28.43 days; beta, 30.11; 95% confidence interval, 12.42-47.81; P=.001), rates of spontaneous preterm birth at <32 weeks (16.7% vs 54.2%; adjusted odds ratio, 0.10; 95% confidence interval, 0.01-0.61; P=.020) and <34 weeks (54.2% vs 83.3%, adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.66; P=.019) of gestation was significantly decreased, and neonatal birthweight was significantly increased (2023.96±510.35 vs 1421.77±611.40 g; beta, 702.40; 95% confidence interval, 297.02-1107.78; P=.001) in the ultrasound-indicated cerclage group when compared with the control group.

CONCLUSION

Cerclage among women with twin pregnancies with a transvaginal cervical length <25 mm may reduce the rate of spontaneous preterm birth and improve perinatal and neonatal outcomes when compared with expectant management. It is worth noting that even with a short transvaginal cervical length of 15 to 24 mm, cerclage will significantly decrease the risk of delivery at <36 weeks' gestation and prolong pregnancy latency. Among women with a short transvaginal cervical length <15 mm, cerclage will significantly decrease the risk of delivery at <32 and <34 weeks' gestation and prolong pregnancy latency.

Cervical length screening for predicting preterm birth: A comparative review of guidelines

A cervical length (CL) assessment may predict preterm birth (PTB). This study aimed to analyze and compare the recommendations of guidelines on the role of CL in the prediction of PTB. There is no consensus regarding universal screening of asymptomatic women without a history of prior spontaneous PTB (sPTB), using CL. On the other hand, CL assessment is recommended in cases with a history of sPTB due to the high recurrence rate. Finally, there is discrepancy regarding CL assessment in asymptomatic women with multiple pregnancy. Although far from perfect, CL measurement remains the best available method to predict PTB.

Ultrasound-Indicated Cerclage in Twin Pregnancies: A Cohort Study

Background

To report the pregnancy and neonatal outcomes in patients with twin pregnancies who underwent ultrasound-indicated cerclage (UIC) and to compare them to patients with singleton pregnancies undergoing the same procedures.

Methods

Patients who underwent UIC between January 2010 and December 2020 at Kangnam Sacred Heart Hospital were reviewed. We compared characteristics, pregnancy, and neonatal outcomes between patients with singleton and twin pregnancies.

Results

A total of 94 women (56 singleton and 38 twin pregnancies) underwent UIC were included. The mean gestational age (GA) at cerclage and preoperative cervical length (CL) were not significantly different. Twin pregnancies were more likely to deliver at earlier median gestations than singletons (singleton, 36 + 1 weeks vs twin, 32 + 6 weeks, and p = 0.004). The frequency of preterm delivery <34 weeks in twin group was higher than in singleton group (15 (26.8%) vs 20 (52.6%) and p =0.016). However, the frequency of preterm delivery <32, <28, and <24 weeks was not significantly different between two groups. Although neonatal weights in singleton pregnancies were heavier than twin pregnancies, neonatal mortality and morbidities were not significantly different between two groups. Among various factors contributing to preterm birth, preoperative CL ≤ 15 mm was independently associated with a higher risk of preterm delivery before 34 weeks. Furthermore, pregnancy and neonatal outcomes of twin pregnancies with cervical length ≤ 15 mm are comparable with those of singleton pregnancies (GA at delivery, singleton, 35 + 1 weeks vs twin, 32 + 5 weeks, and p = 0.24; neonatal mortality, singleton, 3.4% vs twin, 4.8%, and p = 0.64).

Conclusion

The pregnancy and neonatal outcomes of UIC in twin pregnancies were comparable to those in singleton pregnancies, especially when CL is ≤15 mm. UIC might be considered a safe procedure for twin pregnancies.

Comparison of transvaginal cervical cerclage versus laparoscopic abdominal cervical cerclage in cervical insufficiency: a retrospective study from a single centre

Background

Cervical cerclage has been proposed as an effective treatment for cervical insufficiency, but there has been controversy regarding the surgical options of cervical cerclage in singleton and twin pregnancies. This study aimed to compare the pregnancy outcomes between transvaginal cervical cerclage (TVC) and laparoscopic abdominal cervical cerclage (LAC) in patients with cervical insufficiency. We also aimed to evaluate the efficacy and safety, and provide more evidence to support the application of cervical cerclage in twin pregnancies.

Methods

A retrospective study was carried out from January 2015 to December 2021. The primary outcomes were the incidence of spontaneous preterm birth (sPTB) < 24 weeks, < 28, < 32, < 34 weeks, and < 37weeks, gestational age at delivery, and the incidence of admission for threatened abortion or preterm birth after cervical cerclage. The secondary outcomes included admission to the Neonatal Intensive Care Unit, adverse neonatal outcomes and neonatal death. We also analysed the pregnancy outcomes of twin pregnancies after cervical cerclage.

Results

A total of 289 patients were identified as eligible for inclusion. The LAC group (n = 56) had a very low incidence of sPTB ˂ 34 weeks, and it was associated with a significant decrease in sPTB < 28 weeks, ˂32 weeks, ˂34 and < 37 weeks, and admission to the hospital during pregnancy for threatened abortion or preterm birth after cervical cerclage (0 vs.27%; 1.8% vs. 40.3%; 7.1% vs. 46.8%; 14% vs. 63.5%, 8.9% vs. 62.2%, respectively; P < 0.001), and high in gestational age at delivery compared with the TVC group (n = 233) (38.3 weeks vs.34.4 weeks,P < 0.001). Neonatal outcomes in the LAC group were significantly better than those in the TVC group. The mean gestational age at delivery was 34.3 ± 1.8 weeks, with a total foetal survival rate of 100% without serious neonatal complications in twin pregnancies with LAC.

Conclusion

In patients with cervical insufficiency, LAC appears to have better pregnancy outcomes than TVC. For some patients, LAC is a recommended option and may be selected as the first choice. Even in twin pregnancies, cervical cerclage can improve pregnancy outcomes with a longer latency period, especially in the LAC group.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05108-w.

Guideline No. 428: Management of Dichorionic Twin Pregnancies

OBJECTIVE

To review evidence-based recommendations for the management of dichorionic twin pregnancies.

TARGET POPULATION

Pregnant women with a dichorionic twin pregnancy.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline may improve the management of twin pregnancies and reduce neonatal and maternal morbidity and mortality.

EVIDENCE

Published literature was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary (e.g., twin, preterm birth). Results were restricted to systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date limits, but results were limited to English- or French-language materials.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

Obstetricians, family physicians, nurses, midwives, maternal-fetal medicine specialists, radiologists, and other health care providers who care for women with twin pregnancies.

SUMMARY STATEMENTS

RECOMMENDATIONS.

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.

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.

Oil-based vitamin E oral spray for oral health in pregnancy

Aim: To assess the efficacy of vitamin E oral spray in pregnancy. Materials & methods: This was a retrospective study aimed to evaluate efficacy of vitamin E oral spray (vitamin E acetate in a medium chain tryglicerides vehicle – patented formulation) starting from the first trimester of pregnancy, with a control group. Results: A total of 100 women were included in the study and were compared with a matched control group. Only 25/200 women reported to have at least one teeth cleaning during pregnancy. Women who received the oral spray had a significantly lower risk of preterm birth compared with the control group, and lower risk of periodontal diseases Conclusion: Use of oil-based vitamin E oral spray in pregnancy is associated with a decreased risk of periodontal diseases and therefore preterm birth.

Ultrasound-Indicated Cervical Cerclage Efficacy Between 16 and 28 Weeks of Gestation in Twin Pregnancy: Retrospective Cohort Study

Objective

The aim of this study is to determine if cervical cerclage administration reduces the preterm birth (PTB) rate at a gestational age (GA) of 16–28 weeks in women with twin pregnancy.

Methods

This is a retrospective cohort study on asymptomatic twin pregnancy with an ultrasound-identified cervix length (CL) of ≦25 mm. The patients were divided into two groups: ultrasound-indicated cerclage (UIC) group and control (expectant management) group. The primary outcome was a PTB rate at <34 weeks. A logistic regression was also performed, and a subgroup analysis stratified by CL and GA at first short cervix diagnosis was planned.

Results

In all 320 women, there were no differences in the overall <34-week PTB rates and neonatal outcomes between the UIC group and control group. After performing a multivariate logistic regression analysis, the subgroup analyses were planned. In patients with a CL of ≦15 mm, the <34-week PTB rate was significantly decreased in the UIC subgroup compared with the control subgroup (60.78% vs 78.26%; odds ratio (OR) = 0.43, confidence interval (CI) = 95% [0.22–0.86]; and p = 0.020). In patients with a first short cervix diagnosis GA of ≦24 weeks, the <34-week PTB rate was significantly decreased in the UIC subgroup when compared with the control subgroup (61.54% vs 84.75%; OR = 0.29; CI = 95% [0.13–0.63]; and p = 0.001). Furthermore, compared with the control groups, the UIC groups had higher mean birth weight, lower perinatal mortality, and lower NICU admission, and the differences were statistically significant.

Conclusion

UIC could significantly reduce the <34-week PTB rate and improve perinatal outcomes in patients with a CL of ≦15mm or first short cervix diagnosis GA of ≦24 weeks with asymptomatic twin pregnancy during the second trimester.

Prevention of preterm birth in twin pregnancies

Twins represent 3.2% of all live births; however, they account for 20.0% of all preterm deliveries, with 60.0% and 10.7% of twins delivered before 37 and 32 weeks' gestation, respectively. Twin pregnancies have 5 times higher risk of early neonatal and infant death related to prematurity. Monochorionic twins have a higher incidence of both indicated and spontaneous preterm delivery than dichorionic twins. Transvaginal ultrasound of the cervical length before 24 weeks' gestation is the best tool to predict preterm birth, independent of other risk factors. Among all evaluated therapies to decrease or prevent preterm birth in twin pregnancies, the use of vaginal progesterone in women with a transvaginal cervical length of <25 mm decreased neonatal morbidity, and physical examination-indicated cerclage in women with a cervical dilation of >1 cm showed a significant decrease in preterm birth at different gestational ages and perinatal mortality.

Emergency cervical cerclage in twin and singleton pregnancies with 0-mm cervical length or prolapsed membranes

INTRODUCTION

Cervical cerclage is controversial in twin pregnancies, although recent data from the USA supports its use where "physical examination-indicated". Limited data exist, however, in the extreme situation of 0-mm ultrasound-measured cervical length or even prolapsed membranes. This research compares the success of emergency cervical cerclage in multiple and singleton pregnancies.

MATERIAL AND METHODS

This is a retrospective cohort study of all such cerclages performed at a tertiary hospital over a 15-year period. "Emergency" was where transvaginal ultrasound-assessed cervical length was 0 mm, with amniotic membranes at or beyond the external cervical os. Exclusion criteria were clinical or biochemical evidence of infection, regular contractions, bleeding, ruptured membranes, or gestation beyond 24⁺⁰  weeks. The primary outcome, or "success", was defined as birth >27⁺⁶  weeks of gestation, with the neonate alive 28 days later with no markers of adverse outcome (seizures, periventricular leukomalacia, intracranial hemorrhage more than Grade 2, or necrotizing enterocolitis). Demographic and cerclage variables were assessed against the primary outcome. Variables correlated with success were analyzed between multiple and singleton pregnancies. Comparison of all adverse outcomes was then adjusted using logistic regression.

RESULTS

A total of 135 pregnancies were included (107 singletons and 28 multiples [all twins]). Success was achieved in 79 (58.5%; 57.9% in singletons, 60.7% in twins). Nulliparity, in utero transfer, symptoms, prolapsed membranes, and dilation more than 3 cm were predictors of failure, but twin pregnancy was not. After controlling for potential confounding variables, there was no significant difference in measures of success between singleton and twin pregnancies, apart from higher rates of neonatal unit admission.

CONCLUSIONS

Emergency cervical cerclage, even in extreme situations, is as effective in twin pregnancies as it is in singletons.

C-STICH2: emergency cervical cerclage to prevent miscarriage and preterm birth-study protocol for a randomised controlled trial

Background

Cervical cerclage is a recognised treatment to prevent late miscarriage and pre-term birth (PTB). Emergency cervical cerclage (ECC) for cervical dilatation with exposed unruptured membranes is less common and the potential benefits of cerclage are less certain. A randomised control trial is needed to accurately assess the effectiveness of ECC in preventing pregnancy loss compared to an expectant approach.

Methods

C-STICH2 is a multicentre randomised controlled trial in which women presenting with cervical dilatation and unruptured exposed membranes at 16 + 0 to 27 + 6 weeks gestation are randomised to ECC or expectant management. Trial design includes 18 month internal pilot with embedded qualitative process evaluation, minimal data set and a within-trial health economic analysis.

Inclusion criteria are ≥16 years, singleton pregnancy, exposed membranes at the external os, gestation 16 + 0–27 + 6 weeks, and informed consent. Exclusion criteria are contraindication to cerclage, cerclage in situ or previous cerclage in this pregnancy.

Randomisation occurs via an online service in a 1:1 ratio, using a minimisation algorithm to reduce chance imbalances in key prognostic variables (site, gestation and dilatation). Primary outcome is pregnancy loss; a composite including miscarriage, termination of pregnancy and perinatal mortality defined as stillbirth and neonatal death in the first week of life. Secondary outcomes include all core outcomes for PTB. Two-year development outcomes will be assessed using general health and Parent Report of Children’s Abilities-Revised (PARCA-R) questionnaires. Intended sample size is 260 participants (130 each arm) based on 60% rate of pregnancy loss in the expectant management arm and 40% in the ECC arm, with 90% power and alpha 0.05. Analysis will be by intention-to-treat.

Discussion

To date there has been one small trial of ECC in 23 participants which included twin and singleton pregnancies. This small trial along with the largest observational study (n = 161) found ECC to prolong pregnancy duration and reduce deliveries before 34 weeks gestation. It is important to generate high quality evidence on the effectiveness of ECC in preventing pregnancy loss, and improve understanding of the prevalence of the condition and frequency of complications associated with ECC. An adequately powered RCT will provide the highest quality evidence regarding optimum care for these women and their babies.

Trial registration

ISRCTN Registry ISRCTN12981869. Registered on 13th June 2018.

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.

The Arabin pessary to prevent preterm birth in women with a twin pregnancy and a short cervix: the STOPPIT 2 RCT

BACKGROUND

Preterm birth is common in twins and accounts for significant mortality and morbidity. There are no effective preventative treatments. Some studies have suggested that, in twin pregnancy complicated by a short cervix, the Arabin pessary, which fits around the cervix and can be inserted as an outpatient procedure, reduces preterm birth and prevents neonatal morbidity.

OBJECTIVE

STOPPIT 2 aimed to evaluate the clinical utility of the Arabin cervical pessary in preventing preterm birth in women with a twin pregnancy and a short cervix.

DESIGN

STOPPIT 2 was a pragmatic, open label, multicentre randomised controlled trial with two treatment group - the Arabin pessary plus standard care (intervention) and standard care alone (control). Participants were initially recruited into the screening phase of the study, when cervical length was measured. Women with a measured cervical length of ≤ 35 mm were then recruited into the treatment phase of the study. An economic evaluation considered cost-effectiveness and a qualitative substudy explored the experiences of participants and clinicians.

SETTING

Antenatal clinics in the UK and elsewhere in Europe.

PARTICIPANTS

Women with twin pregnancy at < 21 weeks' gestation with known chorionicity and gestation established by scan at ≤ 16 weeks' gestation.

INTERVENTIONS

Ultrasound scan to establish cervical length. Women with a cervical length of ≤ 35 mm at 18^+ 0-20^+ 6 weeks' gestation were randomised to standard care or Arabin pessary plus standard care. Randomisation was performed by computer and accessed through a web-based browser.

MAIN OUTCOME MEASURES

Obstetric - all births before 34^+ 0 weeks' gestation following the spontaneous onset of labour; and neonatal - composite of adverse outcomes, including stillbirth or neonatal death, periventricular leukomalacia, early respiratory morbidity, intraventricular haemorrhage, necrotising enterocolitis or proven sepsis, all measured up to 28 days after the expected date of delivery.

RESULTS

A total of 2228 participants were recruited to the screening phase, of whom 2170 received a scan and 503 were randomised: 250 to Arabin pessary and 253 to standard care alone. The rate of the primary obstetric outcome was 18.4% (46/250) in the intervention group and 20.6% (52/253) in the control group (adjusted odds ratio 0.87, 95% confidence interval 0.55 to 1.38; p = 0.54). The rate of the primary neonatal outcome was 13.4% (67/500) and 15.0% (76/506) in the intervention group and control group, respectively (adjusted odds ratio 0.86, 95% confidence interval 0.54 to 1.36; p = 0.52). The pessary was largely well tolerated and clinicians found insertion and removal 'easy' or 'fairly easy' in the majority of instances. The simple costs analysis showed that pessary treatment is no more costly than standard care.

LIMITATIONS

There was the possibility of a type II error around smaller than anticipated benefit.

CONCLUSIONS

In this study, the Arabin pessary did not reduce preterm birth or adverse neonatal outcomes in women with a twin pregnancy and a short cervix. The pessary either is ineffective at reducing preterm birth or has an effect size of < 0.4.

FUTURE WORK

Women with twin pregnancy remain at risk of preterm birth; work is required to find treatments for this.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN98835694 and ClinicalTrials.gov NCT02235181.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 44. See the NIHR Journals Library website for further project information.

Successful cervical cerclage in a dichorionic diamniotic twin pregnancy: A case report

A 26-year-old primigravid woman presented with a dichorionic diamniotic twin pregnancy after 7 years of infertility. No formal ultrasound was performed until a morphology check at 19 weeks and 4 days of gestation, at which time a shortened cervix was identified. The patient was already on vaginal progesterone pessaries from conception, as per her infertility specialist, and was advised to change to a rectal route of administration. At 20 weeks and 5 days, progesterone pessaries were increased to twice daily. A repeat scan at 21 weeks and 4 days showed a funnelled cervix 29 mm in length, a closed portion of 4-6 mm and bulging membranes. A speculum examination at this time showed a shortened cervix, 5 mm open, with visible membranes. A cervical cerclage was placed at 21 weeks and 5 days. The patient was given oral antibiotics for 1 week and was continued on progesterone pessaries. The patient was managed through the twins clinic and had serial ultrasound scans throughout the pregnancy. She went on to develop gestational diabetes and pre-eclampsia. She had a caesarean section at 33 weeks and 4 days due to pre-eclampsia, with abnormal doppler scans. Cervical cerclage was removed at the time of the caesarean section. Both twins were admitted to the nursery for prematurity and progressed well. This case report illustrates how a cervical cerclage can be utilised successfully in a primigravid dichorionic diamniotic twin pregnancy.

Analysis of maternal and neonatal outcomes using cervical cerclage or conservative treatment in singleton gestations with a sonographic short cervix

To investigate the effect of cervical cerclage or conservative treatment on maternal and neonatal outcomes in singleton gestations with a sonographic short cervix, and further compare the relative treatment value.A retrospective study was conducted among women with singleton gestations who had a short cervical length (<25 mm) determined by ultrasound during the period of 14 to 24 weeks' gestation in our institution. We collected clinical data and grouped the patients according to a previous spontaneous preterm birth (PTB) at <34 weeks of gestation or second trimester loss (STL) and sub-grouped according to treatment option, further comparing the maternal and neonatal outcomes between different groups.In the PTB or STL history cohort, the cerclage group had a later gestational age at delivery (35.3 ± 3.9 weeks vs 31.6 ± 6.7 weeks) and a lower rate of perinatal deaths (2% vs 29.3%) compared with the conservative treatment group. In the non-PTB-STL history cohort, the maternal and neonatal outcomes were not significantly different between the cerclage group and conservative treatment group. More importantly, for patients with a sonographic short cervix who received cervical cerclage, there was no significant difference in the maternal and neonatal outcomes between the non-PTB-STL group and PTB or STL group.For singleton pregnant with a history of spontaneous PTB or STL and a short cervical length (<25 mm), cervical cerclage can significantly improve maternal and neonatal outcomes; however, conservative treatment (less invasive and expensive than cervical cerclage) was more suitable for those pregnant women without a previous PTB and STL history.

Role of progesterone, cerclage and pessary in preventing preterm birth in twin pregnancies: A systematic review and network meta-analysis

OBJECTIVE

To determine the role of progesterone, pessary and cervical cerclage in reducing the risk of (preterm birth) PTB in twin pregnancies and compare these interventions using pairwise and network meta-analysis.

STUDY DESIGN

Medline, Embase, CINAHL and Cochrane databases were explored. The inclusion criteria were studies in which twin pregnancies were randomized to an intervention for the prevention of PTB (any type of progesterone, cervical cerclage, cervical pessary, or any combination of these) or to a control group (e.g. placebo or treatment as usual). Interventions of interest were either progesterone [vaginal or oral natural progesterone or intramuscular 17a-hydroxyprogesterone caproate (17-OHPC)], cerclage (McDonald or Shirodkar), or cervical pessary. The primary outcome was PTB < 34 weeks of gestation. Both primary and secondary outcomes were explored in an unselected population of twin pregnancies and in women at higher risk of PTB (defined as those with cervical length <25 mm). Random-effect head-to-head and a multiple-treatment meta-analyses were used to analyze the data and results expressed as risk ratios.

RESULTS

26 studies were included in the meta-analysis. When considering an unselected population of twin pregnancies, vaginal progesterone, intra-muscular17-OHPC or pessary did not reduce the risk of PTB < 34 weeks of gestation (all p > 0.05). When stratifying the analysis for spontaneous PTB, neither pessary, vaginal or intramuscular 17-OHPC were associated with a significant reduction in the risk of PTB compared to controls (all p > 0.05), while there was no study on cerclage which explored this outcome in an unselected population of twin pregnancies. When considering twin pregnancies with short cervical length (≤25 mm), there was no contribution of either pessary, vaginal progesterone, intra-muscular 17-OHPC or cerclage in reducing the risk of overall PTB < 34 weeks of gestation.

CONCLUSIONS

Cervical pessary, progesterone and cerclage do not show a significant effect in reducing the rate of PTB or perinatal morbidity in twins, either when these interventions are applied to an unselected population of twins or in pregnancies with a short cervix.

Outcomes of ultrasound-indicated cerclage in twin pregnancies with a short cervical length

OBJECTIVE

To investigate the outcomes of ultrasound-indicated cerclage in dichorionic-diamniotic (DCDA) twin pregnancies with a short cervical length.

MATERIALS AND METHODS

This was a retrospective cohort study of DCDA twin pregnancies with a short cervical length (≤25 mm) from January 2000 to July 2017 to compare maternal and neonatal outcomes. Additional sub-analysis was performed by dividing the patients into two subgroups by a cervical length ≤15 mm and between 16 and 25 mm.

RESULTS

One hundred and eight women were initially diagnosed with twin pregnancies and cervical insufficiency. After excluding cases not meeting the study criteria, 46 women were recruited for analysis, of whom 33 underwent ultrasound-indicated cerclage. The delivery age of the cerclage group was significantly later than the non-cerclage group (34.85 ± 3.91 versus 31.08 ± 5.25 weeks, p = 0.011), and the latency was significantly longer in the cerclage group than in the non-cerclage group (86.09 ± 41.32 versus 52.31 ± 33.24 days, p = 0.014). Sub-analysis revealed that these benefits were significant in the subgroup of a cervical length ≤15 mm. Both first twin (twin A) and second twin (twin B) had a significantly decreased rate of neonatal intensive care unit admission in the cerclage group. However, twin A had more promising outcomes with significantly decreased rates of neonatal respiratory distress syndrome (6.7% versus 50.0%, p = 0.004) and sepsis (0% versus 25.0%, p = 0.019).

CONCLUSION

Ultrasound-indicated cerclage in DCDA twin pregnancies can decrease preterm birth and prolong the latency. It also decreases neonatal morbidity, and is especially beneficial for twin A.

Risk of preterm birth and neonatal outcomes after cerclage placement in triplet pregnancies

BACKGROUND

The number of triplet pregnancies in the United States has increased significantly. Perinatal morbidity and mortality are higher in these pregnancies mainly due to higher preterm birth rates. Interventions to decrease the risk of preterm delivery in this population are needed. Evidence regarding cerclage placement in triplets is limited. We performed a population-based, retrospective cohort study to study the risk of preterm birth and neonatal outcomes after cerclage placement in triplet pregnancies.

METHODS

All U.S. triplet deliveries from 2006 to 2013 with risk factors for cervical insufficiency were selected, excluding cases with indicated preterm delivery. Cases were categorized according to cerclage placement status. The risk of preterm birth and adverse neonatal outcomes were calculated using propensity score analysis, generalized linear, and logistic regression models.

RESULTS

From ∼33 million deliveries, 43,000 were triplets, and 7308 fulfilled eligibility criteria. There was no difference in the gestational age at delivery between the cerclage and noncerclage groups, aOR (95% CI) = 1.0(0.9-1.0). The difference between the risk of preterm delivery at <34 weeks and <32 weeks was not statistically significant. The risk of the composite outcome of neonatal complications was higher in the cerclage compared to the noncerclage group, aOR (95% CI) = 1.5 (1.1-2.2).

CONCLUSIONS

Cerclage placement in triplet pregnancies does not appear to decrease preterm birth rates and seems to increase the risk of neonatal complications.

Prevention of preterm birth in multiples

PURPOSE OF REVIEW

Multifetal pregnancy carries increased risk of preterm delivery, and consensus on management options to prevent early birth in this population has not been reached. This review serves to summarize the most contemporary findings on this controversial topic.

RECENT FINDINGS

Examination-indicated cerclage is effective in reducing preterm birth in twin pregnancies, whereas cerclages for other indications are less convincing. Cervical pessary may be beneficial for patients with a short cervix and in those who have had threatened preterm labor. Progesterone supplementation for multifetal gestation alone is not beneficial, but it can be considered in those with a history of prior singleton preterm birth.

SUMMARY

Interventions for preterm birth prevention in multiple gestations remain under investigation, and further data is required in order to reach consensus for this high-risk population.

Efficacy of physical examination-indicated cerclage in twin pregnancies compared with singleton pregnancies: a systematic review and meta-analysis

INTRODUCTION

To compare the pregnancy outcomes of physical examination-indicated cerclage (PEIC) between twin and singleton pregnancies with acute cervical insufficiency.

EVIDENCE ACQUISITION

We searched Medline, Ovid, Scopus, EBSCO, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials from their commencement until Dec 2019 for relevant studies. Patient-level data abstraction and analysis were done by two independent authors.

EVIDENCE SYNTHESIS

A total of five studies with 786 women were included in the final analysis. The pooled outcomes showed that PEIC was associated with a similar reduction in preterm birth (PTB) at <32 (Risk ratio [RR] 0.93, 95% CI 0.79-1.11, I²⁼0%, P=0.43), and 28 (RR 1.03, 95% CI 0.82-1.29, I²⁼0%, P=0.81) weeks of gestation; however, a much higher frequency of PTB was observed at <36 (RR 0.74, 95% CI 0.66-0.83, I²⁼0%, P<0.000), and 34 (RR 0.80, 95% CI 0.68-0.93, I²⁼0%, P=0.004) weeks of gestation in twin pregnancies than in singleton pregnancies. No significant differences in perinatal outcomes, including neonatal death (RR 1.03, 95% CI 0.64-1.67, I²⁼52%, P=0.900), stillbirth (RR 0.73, 95% CI 0.37-1.44, I²=0%, P=0.360), perinatal mortality (RR 0.94, 95% CI 0.65-1.38, P=0.760) and neonatal complications were found between twin and singleton pregnancies.

CONCLUSIONS

Our meta-analysis indicated that PEIC achieved good perinatal prognosis in both singleton and twin pregnancies. However, because the available evidence is insufficient to attain a strong conclusion, so further high-quality trials are needed to confirm our findings.

Cervical pessary in singleton gestations with arrested preterm labor: a randomized clinical trial

BACKGROUND

Cervical pessary has been proven to be effective in reducing the rate of preterm birth in asymptomatic women with singleton gestations and short cervical length in the midtrimester of pregnancy; however, the efficacy of this device in women with arrested preterm labor is still a subject of debate.

OBJECTIVE

This study aimed to test the hypothesis that the use of a cervical pessary in women with singleton pregnancy and arrested preterm labor would reduce the risk of preterm birth at <37 weeks of gestation.

STUDY DESIGN

This study is a parallel group, nonblinded, randomized trial. Participants included in the study were women with a diagnosis of arrested preterm labor between 24 0/7 and 33 6/7 weeks of gestations. The participants were randomized to either the cervical pessary group or no pessary group in a 1:1 ratio. The primary endpoint was preterm birth at <37 weeks of gestation. A sample size of 120 participants was determined, but the trial was concluded before the completion of enrollment.

RESULTS

A total of 61 women with singleton pregnancies and arrested preterm labor at 24 0/7 to 33 6/7 weeks of gestation were enrolled in the trial. Of the 61 women, 32 were randomized to the cervical pessary group and 29 to the control group. Preterm birth at <37 weeks of gestation occurred in 14 women (43.8%) in the pessary group and 6 women (20.7%) in the control group (relative risk, 2.98; 95% confidence interval, 0.96-9.30).

CONCLUSION

In this underpowered trial, among women with singleton pregnancies and arrested preterm labor, compared with no pessary use, the use of a cervical pessary does not result in a lower rate of preterm birth at <37 weeks of gestation.

A comparison of pregnancy outcome of emergency modified transvaginal cervicoisthmic cerclage performed in twin and singleton pregnancies

PURPOSE

To compare the pregnancy outcome of emergency cerclage performed in twin and singleton pregnancies.

METHODS

A retrospective trial was carried out in the Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital in Zhejiang, China, from January 2013 to December 2018. A total of 89 women with acute cervical incompetence underwent the emergency cerclage. Main outcome measures were gestational age at delivery and the fetal outcome.

RESULTS

There were 31 twin and 58 singleton pregnancies that underwent emergency cerclage. In singleton pregnancies, gestational age at delivery (31.57 ± 6.11 vs 28.81 ± 4.34, p = 0.016), and prolongation of pregnancy (8.69 ± 6.13 vs 5.41 ± 3.72, p < 0.001) were greater, and the preterm delivery rate before 34 weeks was lower (53.4% vs 80.6%, p = 0.011) compared with twin pregnancies. Fetal weight was greater in singletons than in twins (2377.3 ± 862.1 vs 1630.3 ± 557.6, p < 0.001), but the fetal survival rate was similar. The proportion of twin gestations was significantly higher in the group with preterm delivery before 34 weeks (44.6% vs 18.2%, p = 0.011) and the proportion of previous term delivery was higher in the group with delivery at or after 34 weeks (30.3% vs 12.5%, p = 0.039). The group with preterm delivery before 34 weeks had a significantly larger size of visible membranes at cerclage than the group with delivery at or after 34 weeks (2.23 ± 0.86 vs 1.64 ± 0.80, p = 0.001). In binary logistic regression analysis, twin gestations and a larger size of visible membranes were associated with an increased risk of preterm delivery.

CONCLUSION

The pregnancy outcome of emergency cerclage appears to have a better prognosis in singleton pregnancies than in twin pregnancies, and twin pregnancy is a risk factor for preterm delivery.

Comparison of cerclage and pessary in prevention of preterm birth in twin pregnancies

Background: The preterm labor has increased in multiple pregnancies over the past 2 decades. Preterm labor has led to increase in neonatal mortality rates, long-term morbidity, respiratory distress, and neonatal infections. Thus, this study aimed at investigating the effect of cerclage versus pessary on the prevention of preterm birth in twin pregnancies.

Methods: This prospective randomized clinical trial was performed on 50 women pregnant with twins who visited Taleghani hospital in 2016-2018. Their cervical length, which was measured by transvaginal ultrasonography (TVS), was less than 30 millimeters at week 14 of pregnancy. The participants were randomly divided into 2 groups (n=25). They separately underwent cervical pessary and cerclage. McDonald's procedure was performed in cerclage group from 14 to 27 weeks. The suture material was Mersilene Ethicon 5-0 double-armed s14 needle. Ring hodge pessary was also inserted in the vagina of the participants in the pessary group. All the patients were injected 250 mg intramuscular 17 alpha-hydroxyprogesterone caproate weekly from week 16 to week 36. All statistical analyses were performed using SPSS 18 software.

Results: The results of this study showed that the mean ± standard deviation (SD) for pregnancy length of the cerclage and pessary groups were 238.6±32.4 and 223.6±16.6, respectively. Also, significant differences were found between the 2 groups (p=0.048). No significant difference was found in pregnancy (p=0.565), length of pessary/cerclage use (p=0.491), and BMI before and after delivery between the cerclage and pessary groups (p>0.05).

Conclusion: The use of cerclage in twin pregnancies is recommended to increase the length of pregnancy.

Cervical stitch (cerclage) in combination with other treatments for preventing spontaneous preterm birth in singleton pregnancies

BACKGROUND

Preterm birth (PTB) remains the foremost global cause of perinatal morbidity and mortality. Thus, the prevention of spontaneous PTB still remains of critical importance. In an attempt to prevent PTB in singleton pregnancies, cervical cerclage, in combination with other treatments, has been advocated. This is because, cervical cerclage is an intervention that is commonly recommended in women with a short cervix at high risk of preterm birth but, despite this, many women still deliver prematurely, as the biological mechanism is incompletely understood. Additionally, previous Cochrane Reviews have been published on the effectiveness of cervical cerclage in singleton and multiple pregnancies, however, none has evaluated the effectiveness of using cervical cerclage in combination with other treatments.

OBJECTIVES

To assess whether antibiotics administration, vaginal pessary, reinforcing or second cerclage placement, tocolytic, progesterone, or other interventions at the time of cervical cerclage placement prolong singleton gestation in women at high risk of pregnancy loss based on prior history and/or ultrasound finding of 'short cervix' and/or physical examination. History-indicated cerclage is defined as a cerclage placed usually between 12 and 15 weeks gestation based solely on poor prior obstetrical history, e.g. multiple second trimester losses due to painless dilatation. Ultrasound-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation for transvaginal ultrasound cervical length < 20 mm in a woman without cervical dilatation. Physical exam-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation because of cervical dilatation of one or more centimetres detected on physical (manual) examination.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (26 September 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included published, unpublished or ongoing randomised controlled trial (RCTs). Studies using a cluster-RCT design were also eligible for inclusion in this review but none were identified. We excluded quasi-RCTs (e.g. those randomised by date of birth or hospital number) and studies using a cross-over design. We also excluded studies that specified addition of the combination therapy after cervical cerclage because the woman subsequently became symptomatic. We included studies comparing cervical cerclage in combination with one, two or more interventions with cervical cerclage alone in singleton pregnancies.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts of all retrieved articles, selected studies for inclusion, extracted data, assessed risk of bias, and evaluated the certainty of the evidence for this review's main outcomes. Data were checked for accuracy. Standard Cochrane review methods were used throughout.

MAIN RESULTS

We identified two studies (involving a total of 73 women) comparing cervical cerclage alone to a different comparator. We also identified three ongoing studies (one investigating vaginal progesterone after cerclage, and two investigating cerclage plus pessary). One study (20 women), conducted in the UK, comparing cervical cerclage in combination with a tocolytic (salbutamol) with cervical cerclage alone in women with singleton pregnancy did not provide any useable data for this review. The other study (involving 53 women, with data from 50 women) took place in the USA and compared cervical cerclage in combination with a tocolytic (indomethacin) and antibiotics (cefazolin or clindamycin) versus cervical cerclage alone - this study did provide useable data for this review (and the study authors also provided additional data on request) but meta-analyses were not possible. This study was generally at a low risk of bias, apart from issues relating to blinding. We downgraded the certainty of evidence for serious risk of bias and imprecision (few participants, few events and wide 95% confidence intervals). Cervical cerclage in combination with an antibiotic and tocolytic versus cervical cerclage alone (one study, 50 women/babies) We are unclear about the effect of cervical cerclage in combination with antibiotics and a tocolytic compared with cervical cerclage alone on the risk of serious neonatal morbidity (RR 0.62, 95% CI 0.31 to 1.24; very low-certainty evidence); perinatal loss (data for miscarriage and stillbirth only - data not available for neonatal death) (RR 0.46, 95% CI 0.13 to 1.64; very low-certainty evidence) or preterm birth < 34 completed weeks of pregnancy (RR 0.78, 95% CI 0.44 to 1.40; very low-certainty evidence). There were no stillbirths (intrauterine death at 24 or more weeks). The trial authors did not report on the numbers of babies discharged home healthy (without obvious pathology) or on the risk of neonatal death.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to evaluate the effect of combining a tocolytic (indomethacin) and antibiotics (cefazolin/clindamycin) with cervical cerclage compared with cervical cerclage alone for preventing spontaneous PTB in women with singleton pregnancies. Future studies should recruit sufficient numbers of women to provide meaningful results and should measure neonatal death and numbers of babies discharged home healthy, as well as other important outcomes listed in this review. We did not identify any studies looking at other treatments in combination with cervical cerclage. Future research needs to focus on the role of other interventions such as vaginal support pessary, reinforcing or second cervical cerclage placement, 17-alpha-hydroxyprogesterone caproate or dydrogesterone or vaginal micronised progesterone, omega-3 long chain polyunsaturated fatty acid supplementation and bed rest.

Practice patterns of obstetric care in twin gestations: the value of MFM consultation

OBJECTIVES

To evaluate the practice patterns among Lebanese obstetricians regarding obstetric care of twins and to compare selected practice patterns between general obstetricians and maternal fetal medicine physicians.

METHODS

Questionnaires distributed during the annual meeting of the Lebanese Society of Obstetrics and Gynecology.

RESULTS

Questionnaires were returned by 69.2% of the 296 physicians approached. Ten percent had fellowship training in Maternal Fetal Medicine (MFM). Thirty-nine percent perform cervical length measurement at 20-24 weeks of gestation and 34% recommend vaginal progesterone in case of a short cervix. When comparing selected practice patterns between MFM & general obstetricians, MFM specialists were less likely to perform cervical cerclage in the first trimester (5.9% versus 49%, p = .001), more likely to offer prenatal screening for aneuploidy (66.6% vs 46.4%, p = .03), less likely to use vaginal progesterone in the second trimester in the case of a short cervix (42.1% vs 61.8%, p = .04), less likely to perform serial ultrasound exam in the third trimester to assess fetal growth (50% vs 78%, p = .005) and more likely to deliver monoamniotic twins at 32-34 weeks of gestation (55% vs 37%, p = .05).

CONCLUSION

Because of the different background of the Lebanese physicians, MFM specialists are more likely to follow obstetric care guidelines in twin gestation.

Physical examination-indicated cerclage in twin pregnancy: a retrospective cohort study

PURPOSE

This study aimed to evaluate the efficacy of physical examination-indicated cerclage in twin pregnancies and compare it with those that received conservative management.

METHODS

We used a retrospective cohort study design of asymptomatic twin pregnancies identified with physical examination indications at 14-26 weeks from 2015 through 2019 at Fujian Maternity and Child Health Hospital. The primary outcomes were gestational age (GA) at delivery and the incidence of spontaneous preterm birth (SPTB) at < 34 weeks, < 32 weeks, < 28 weeks, and < 24 weeks. The main secondary outcomes were latency period from diagnosis to delivery, composite neonatal adverse outcome and neonatal survival at discharge.

RESULTS

Thirty-one women with twin pregnancies were managed with physical examination-indicated cerclage, and another 31 received expectant management. The demographic characteristics of the two groups were not significantly different. GA at delivery was significantly later in the cerclage group than in the controls: 32.53 ± 4.78 vs. 27.53 ± 4.15 weeks, with a mean difference of 5.00 weeks [95% confidence interval (CI), 2.73-7.28]. There were significant decreases in the incidence of spontaneous preterm birth (SPTB) at < 34 weeks, < 32 weeks, < 28 weeks, and < 24 weeks in the cerclage group. The interval from diagnosis to delivery was increased with cerclage by a mean difference of 4.37 weeks (95% CI, 1.96-7.06). Regarding neonatal outcome, the perinatal mortality rate in the cerclage group was significantly reduced compared to that in the control group [8/62 (12.9%) vs. 26/62 (41.9%); P < 0001]. Likewise, the neonatal intensive care unit (NICU) admissions, length of stay in the NICU, and composite adverse neonatal outcome in the cerclage group were significantly reduced.

CONCLUSION

Physical examination-indicated cerclage was associated with significantly later GA at delivery, longer latency period from diagnosis to delivery, decreased incidence of SPTB at any given GA, and improved perinatal outcome compared with the corresponding measures in controls treated conservatively.