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National Collaborating Centre for Women's and Children's Health (UK). Preterm Labour and Birth. London: National Institute for Health and Care Excellence (UK); 2015 Nov. (NICE Guideline, No. 25.)

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Preterm Labour and Birth.

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8‘Rescue’ cervical cerclage

8.1. Introduction

Cervical cerclage, also known as a cervical stitch, is a treatment used to prevent the cervix opening too early and causing either a late miscarriage or preterm birth. Cerclage may be performed as a prophylactic measure where the woman has a history that increases the risk of spontaneous second-trimester loss or preterm delivery and/or cervical shortening seen on ultrasound; this type of cerclage is considered in Chapter 4. It can also be performed as a salvage measure (‘rescue’ or non-prophylactic cerclage) when a woman presents with premature cervical dilation, often with exposed fetal membranes, and in some cases where the membranes have prolapsed into the vagina.

‘Rescue’ cerclage is not a common procedure and is most often performed in the middle trimester around the time of viability. Preventing or delaying preterm birth at this gestation might have significant benefit in terms of reducing mid-trimester loss and avoiding the consequences of extreme prematurity. However, the procedure carries risks and there is uncertainty about which women are most likely to benefit. This chapter considers only ‘rescue’ or non-prophylactic cervical cerclage.

8.2. Review question

What is the clinical effectiveness of non-prophylactic ‘rescue’ cervical cerclage in preventing preterm birth for women in suspected preterm labour?

8.3. Description of included studies

Six studies are included in the review of the role of rescue cervical cerclage (Althuisius 2003, Aoki 2013, Curti 2012, Daskalakis 2006, Olatunbosun 1995, Stupin 2008). As only 1 randomised controlled trial (RCT) was identified to match the protocol (Althuisius 2003), comparative cohort studies were also considered; either prospective (Daskalakis 2006, Olatunbosun 1995) or retrospective (Aoki 2013, Curti 2012, Stupin 2008).

All women included in the studies were at risk of preterm birth. Women who did not have rescue cervical cerclage were confined to bed rest. The additional use of supportive treatment with tocolysis, antibiotics, corticosteroids and low molecular weight heparins varied between the studies.

The lowest gestational age of women included in the studies reviewed was 16+0 weeks while the highest was 27+6 weeks. Mean gestation (standard deviation [SD]) at the time of emergency cerclage was reported only in 3 out of the 6 included studies and was around 22 weeks (22.4 [1.7] weeks, 22.4 [2.1] weeks and 22.2 [3.3] weeks).

8.4. Evidence profile

The search strategies for this chapter can be found in Appendix E, the excluded studies in Appendix G, the evidence tables in Appendix H and the forest plots in Appendix I.

Data is presented in the following GRADE profile:

  • Table 32: GRADE profile for comparison of ‘rescue’ cervical cerclage versus no cerclage
Table 32. GRADE profile for comparison of ‘rescue’ cervical cerclage versus no cerclage.

Table 32

GRADE profile for comparison of ‘rescue’ cervical cerclage versus no cerclage.

For quantitative outcomes, such as the pregnancy prolongation data that were presented by either parametric (mean, SD) or non-parametric (median, range) measures, the GRADE profile includes information only on results from studies with parametric measures that could be used to calculate the absolute effects.

A full description of the characteristics and results of the included studies can be found in the evidence tables in Appendix H.

8.5. Evidence statements

Low and very low quality evidence from 1 small RCT (n=30) and 3 cohort studies (n=32 to 52) found no significant difference for the outcome of neonatal survival in babies whose mothers had rescue cerclage compared with those who did not have cerclage.

Low and very low quality evidence from 3 individual cohorts and 1 RCT (n=23 to 161) showed significantly fewer perinatal deaths and preterm births before 22+0 to 27+6, 32 and 34 weeks in women who had rescue cerclage compared with women who did not. Very low quality evidence from the small RCT and 1 cohort study showed that the interval between the study entry and birth was longer in women who had rescue cerclage compared with women who did not. In addition, low quality evidence from the same RCT showed significantly lower risk of serious neonatal morbidity (defined as admission to neonatal intensive care unit and/or neonatal deaths) in babies whose mothers had cerclage compared with women who did not have cerclage.

The outcomes of neonatal survival and maternal side effects were not found significantly different between the 2 groups (rescue cerclage and no cerclage) based on low to very low quality evidence from 1 small RCT and individual cohort studies.

8.6. Health economics profile

A single search was undertaken for health economic evidence on prophylactic cervical cerclage to prevent preterm labour in women considered to be at risk of preterm labour and birth and rescue cervical cerclage in preventing preterm birth in women in suspected preterm labour. A total of 60 articles were identified by the search. After reviewing titles and abstracts, 3 papers were obtained. These studies were all excluded because they were not economic evaluations or were published conference abstracts. Therefore, no relevant economic evidence was identified for this question.

This question was not identified as a priority for health economic analysis as the Guideline Committee reflected that the intervention would only be relevant for a very small proportion of the patient population.

8.7. Evidence to recommendations

8.7.1. Relative value placed on the outcomes considered

In terms of neonatal outcomes, the Guideline Committee considered neonatal mortality as critical for this review, concluding that any mortality up to 1 year could be reported as a single outcome. The committee included early neonatal survival because only the first week was available for analysis.

Given that the purpose of this intervention is to delay birth, preterm birth and the interval between the procedure and delivery were both prioritised as important outcomes. The committee included neonatal sepsis, chronic lung disease and bronchopulmonary dysplasia as potential associated adverse events. The committee also considered long-term infant neurodevelopmental outcomes, such as neurodevelopmental disability, because these are common adverse events associated with preterm birth and any reduction in these outcomes would be a significant indicator of the effectiveness of the intervention. However, given the absence of available data, the committee agreed that serious neonatal morbidity could be considered as a surrogate for the neonatal adverse events outcomes selected originally.

In terms of maternal outcomes, maternal mortality and maternal adverse effects were prioritised for this review question, including infection requiring intervention and cervical trauma requiring repair, because rescue cerclage is a difficult procedure and there is a potential risk of such events occurring. In addition, the committee felt that evidence regarding maternal emotional and psychological impact should be also assessed, due to the invasive nature of the procedure and considering the stressful circumstances under which it might be conducted (when urgent treatment is required).

8.7.2. Consideration of clinical benefits and harms

The committee recognised that both the randomised and observational evidence supported rescue cerclage for the outcomes of reducing serious neonatal morbidity, reducing preterm birth below 27, 32 and 34 weeks and increasing the interval between intervention and delivery. The committee had serious concerns regarding the lack of data for the outcome of neonatal sepsis as, based on their clinical experience, this was likely to be a significant complication associated with the procedure. They concluded that information about the risks of rescue cerclage, as well as its potential aims and benefits, should be communicated to the woman and their family members or carers as appropriate.

The committee members' clinical opinion was that any benefit of performing rescue cerclage beyond 32 gestational weeks would be limited and may not outweigh the potential harms. They agreed that the recommendation to perform rescue cerclage for women with a dilated cervix and exposed, unruptured membranes should reflect both the quality of reviewed evidence (low to very low) and the gestational age of women included in these studies (between 16+0 and 27+6 weeks).

They were also aware that rescue cerclage can be a technically difficult procedure to perform, requiring specialist skills and expertise to mitigate the risks of maternal or neonatal adverse events.

For these reasons, the committee recommended that the decision for rescue cerclage must be made only after discussion with a consultant obstetrician. The decision should take account of the woman's gestation and her own stated wishes after a full discussion. The committee members decided that, in their clinical opinion, rescue cerclage would cause harm to women with signs of infection, active vaginal bleeding or uterine contractions and so they decided upon a strong recommendation of not offering rescue cerclage to these groups of women.

8.7.3. Consideration of health benefits and resource uses

The committee felt that rescue cerclage was likely to be an expensive intervention due to the setting in which it is delivered and the expertise required of the healthcare professionals providing the care.

They also felt that although the evidence shows a reduction in preterm birth, perinatal death and neonatal morbidity, it was of low quality and the chance of poor outcomes is quite high despite emergency cerclage. However, they acknowledged that the management of preterm birth and the associated outcomes is extremely costly – both financially and in terms of parental anxiety – and therefore if the intervention delayed birth beyond key gestational milestones, then the initial costs incurred would be likely to be offset by large cost savings downstream.

Furthermore, the committee felt that the overall cost impact for health services would be small because rescue cerclage would only be an appropriate intervention for a small proportion of the patient population.

8.7.4. Quality of evidence

The majority of the evidence included was of low to very low quality. Only a small RCT of 30 women was included in the evidence base whereas the rest of the evidence came from cohort studies. Indirectness and imprecision were the main areas affected in the quality assessment of included studies. More specifically, some of the cohorts included were mixed populations in terms of use of additional tocolytics (or other adjunctive treatment) and the inclusion of twin pregnancies. Potential bias in the single RCT arose from the imbalanced allocation of women with multiple pregnancies to treatment groups, which was of particular concern for the committee. The sample size of the included studies was relatively small, thus restricting the confidence in the estimates of effects.

8.7.5. Other considerations

The recommendations were based on both the interpretation of clinical evidence reviewed and on the committee members' expert opinions.

The committee noted that this review did not set out to compare the different types of stitches that could be used and the conclusions of the findings may be limited under these restrictions. They were also aware that there is an existing RCOG guideline on cervical cerclage that provides more detail on how to perform this intervention.

The committee also noted that it would be important to take into account the effectiveness of other possible interventions (such as magnesium sulfate for neuroprotection) when considering whether to offer rescue cerclage at lower gestational ages.

8.7.6. Key conclusions

In light of all their reservations about the evidence on the effectiveness of rescue cerclage, the committee members decided that a decision should be made with caution regarding its application.

For these reasons, the committee felt that women should be clearly informed about the potential risks and benefits of the procedure. It was noted that a specific definition of preterm labour had been used in some of the included studies (dilated cervix with exposed fetal membranes) and that this should be reflected in the recommendations in terms of indications and contraindications for the use of rescue cerclage. They also noted that the gestation at which rescue cerclage was undertaken was an important consideration, as were the skills and experience of the practitioner performing the procedure. The importance of the woman and her partner having confidence and trust in the obstetrician was also highlighted. The committee concluded that whether or not to insert a rescue cervical suture was a complex judgement that should be undertaken on an individualised basis with full involvement of the woman.

The committee also took the view that there should be some obligation to collect data about outcomes of its use in a national registry.

8.8. Recommendations


Do not offer ‘rescue’ cervical cerclage to women with:

  • signs of infection or
  • active vaginal bleeding or
  • uterine contractions.

Consider ‘rescue’ cervical cerclage for women between 16+0 and 27+6 weeks of pregnancy with a dilated cervix and exposed, unruptured fetal membranes:

  • take into account gestational age (being aware that the benefits are likely to be greater for earlier gestations) and the extent of cervical dilatation
  • discuss with a consultant obstetrician and consultant paediatrician.

Explain to women for whom ‘rescue’ cervical cerclage is being considered (and their family members or carers as appropriate):

  • about the risks of the procedure
  • that it aims to delay the birth, and so increase the likelihood of the baby surviving and of reducing serious neonatal morbidity.

8.9. Research recommendations

Research question

What is the clinical effectiveness of ‘rescue’ cerclage in improving outcomes for women at risk of preterm birth?

Why this is needed
Importance to ‘patients’ or the populationThere is some evidence from randomised studies that ‘rescue’ cerclage might be effective in improving neonatal outcomes in women with a dilated cervix and exposed, unruptured fetal membranes. However, there is uncertainty about the magnitude of this effect. The full consequences of this strategy and the subgroups of women at risk of preterm labour who might particularly benefit are not known. A randomised controlled trial would best address this question, but a national registry of the most critical outcomes (neonatal mortality and morbidity, maternal morbidity) could also be considered for women who did not want to participate in a randomised trial but who opted for ‘rescue’ cerclage.
Relevance to NICE guidanceThe importance is high because rescue cerclage is widely used yet its evidence base is of relatively low quality, and it is likely that more high quality evidence would refine or change current recommendations.
Relevance to the NHSIf rescue cerclage is effective in delaying delivery, and this benefit is found to outweigh any harms, then it will be important to define the groups of women who may benefit from this treatment. If effective it has potential to reduce morbidity and mortality, healthcare resources and costs expended on the care of very preterm babies.
National prioritiesNHS Outcomes Framework 2014-5, #1: Preventing people from dying prematurely
Current evidence baseThe Committee recognised that the current evidence base was of low quality and many important questions remain unanswered. There is some evidence that ‘rescue’ cerclage might be effective in improving outcomes in women with a dilated cervix and exposed, unruptured fetal membranes. However, there was uncertainty in the magnitude of this effect and the full consequences and the subgroups of women at risk of preterm labour who might particularly benefit are unknown.
FeasibilityThere is no reason in principle why further trials should not be carried out to address current uncertainties. The Committee felt that a randomised trial would provide the best evidence, but that a registry collection of outcomes (neonatal mortality and morbidity, maternal morbidity) could be considered for women who did not want to participate in a randomised trial but who opted for rescue cerclage.
The ethical issues are not in principle different from those affecting other perinatal trials.
Other commentsTrials would have to be carried out in centres with neonatal facilities equipped to care for very preterm babies.
Copyright © 2015 National Collaborating Centre for Women's and Children's Health.
Bookshelf ID: NBK356055


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