Cervical cerclage and type of suture material: a survey of UK consultants’ practice

A comparison of Mersilene tape versus braided suture in transvaginal cervical cerclage: A retrospective case-control study

OBJECTIVE

Previous studies have indicated that there is an association between cervical cerclage and type of suture material. However, it is still unclear which suture material can provide the greatest benefit to patients who have undergone cerclage. This study investigated the effect of two different suture materials (Mersilene tape vs braided suture) used for transvaginal cervical cerclage placement on maternal outcomes of women with cervical insufficiency.

METHODS

In this retrospective case-control study, 170 women who underwent history-, ultrasound-, or physical examination-indicated transvaginal cervical cerclage were categorized according to suture materials used for cerclage: a total of 96 received Mersilene tape and 74 received braided suture. Study participants received a transvaginal cervical cerclage before 28 weeks and were followed up until delivery to assess pregnancy and neonatal outcomes. The primary outcome was gestational age at delivery. Secondary outcomes included preterm premature rupture of membranes (PPROM), premature rupture of membranes (PROM), chorioamnionitis, neonatal survival rate, and neonatal morbidity.

RESULTS

Out of 170 eligible women, 74 (43.5%) received braided suture while 96 (56.5%) received Mersilene tape. Baseline characteristics were similar between the two groups. The group that received braided suture had a lower incidence of gestational age at delivery <37 weeks (29.2% vs 54.2%, P = 0.046), PPROM (9.5% vs 21.9%, P = 0.029) and PROM (17.6% vs 32.3%, P = 0.028) compared to the group that received Mersilene tape. However, there were no significant differences between the two groups in average gestational age at delivery, the rate of gestational age at delivery <24, <28, <32, and < 34 weeks, chorioamnionitis, and neonatal survival rate, as well as neonatal morbidity.

CONCLUSION

Compared to Mersilene tape, the utilization of braided suture has been significantly associated with a reduction in the incidence of gestational age at delivery <37 weeks, as well as a decreased risk of PPROM and PROM. However, the use of braided sutures did not result in discernible differences in the rates of chorioamnionitis or adverse neonatal outcomes.

Monofilament suture versus braided suture thread to improve pregnancy outcomes after vaginal cervical cerclage (C-STICH): a pragmatic randomised, controlled, phase 3, superiority trial

BACKGROUND

Miscarriage in the second trimester and preterm birth are significant global problems. Vaginal cervical cerclage is performed to prevent pregnancy loss and preterm birth. We aimed to determine the effectiveness of a monofilament suture thread compared with braided suture thread on pregnancy loss rates in women undergoing a cervical cerclage.

METHODS

C-STICH was a pragmatic, randomised, controlled, superiority trial done at 75 obstetric units in the UK. Women with a singleton pregnancy who received a vaginal cervical cerclage due to a history of pregnancy loss or premature birth, or if indicated by ultrasound, were centrally randomised (1:1) using minimisation to receive a monofilament suture or braided suture thread for their cervical cerclage. Women and outcome assessors were masked to allocation as far as possible. The primary outcome was pregnancy loss, defined as miscarriage, stillbirth, or neonatal death in the first week of life, analysed in the intention-to-treat population (ie, all women who were randomly assigned). Safety was also assessed in the intention-to-treat population. The trial was registered with ISRCTN, ISRCTN15373349.

FINDINGS

Between Aug 21, 2015, and Jan 28, 2021, 2049 women were randomly assigned to receive a monofilament suture (n=1025) or braided suture (n=1024). The primary outcome was ascertained in 1003 women in the monofilament suture group and 993 women in the braided suture group. Pregnancy loss occurred in 80 (8·0%) of 1003 women in the monofilament suture group and 75 (7·6%) of 993 women in the braided suture group (adjusted risk ratio 1·05 [95% CI 0·79 to 1·40]; adjusted risk difference 0·002 [95% CI -0·02 to 0·03]).

INTERPRETATION

Monofilament suture did not reduce rate of pregnancy loss when compared with a braided suture. Clinicians should use the results of this trial to facilitate discussions around the choice of suture thread to optimise outcomes.

FUNDING

National Institute of Health Research Health Technology Assessment Programme.

A modified transabdominal cervicoisthmic cerclage with the monofilament thread: Its efficacy and safety for women with extremely short cervix due to cervical conization

AIM

The study aimed to examine the usefulness of modified transabdominal cervicoisthmic cerclage (TAC) using monofilament thread for the prevention of preterm delivery in women with an extremely short cervix after deep conization.

METHODS

We devised a monofilament thread for picking up the seromuscular layer of the site that is slightly cephalad to the internal ostium to prevent injury of the vessels around the uterine cervix. From 2017 to 2020, we performed this modified operation in eight women (nine pregnancies) at 12-16 weeks of gestation with a history of deep cervical conization.

RESULTS

A modified TAC was successfully performed in all patients. There was no measurable bleeding, and all patients were discharged without postoperative complications. Their pregnancy courses after the operation were uneventful. Of nine, one patient had premature uterine contractions and underwent cesarean section at 36 weeks (preterm delivery). In the other eight pregnancies, planned cesarean section was performed after 37 weeks of gestation. The median birth weight of the babies was 2996 g (range 2604-3374 g). All patients were discharged on the sixth postoperative day without complications.

CONCLUSION

A modified TAC can be safely performed and may prolong pregnancy without adverse events in patients with an extremely short cervix.

C-STICH: Cerclage Suture Type for an Insufficient Cervix and its effect on Health outcomes-a multicentre randomised controlled trial

Background

Preterm birth is associated with significant mortality and morbidity for mothers and babies. Women are identified as high risk for preterm birth based on either previous medical/pregnancy history or on ultrasound assessment of the cervix. Women identified as high risk can be offered a cervical cerclage (a purse string stitch) around the cervix (neck of the womb) to reduce the risk of preterm birth. In women who have a cervical cerclage, the procedure can be performed using either a monofilament (single-stranded) or braided (woven) suture material. Both suture materials are routinely used for cervical cerclage and there is uncertainty as to which is superior.

Methods

A multicentre, open, randomised controlled superiority trial of 2050 women presenting at obstetric units, deemed to be at risk of preterm birth and already scheduled to have a cervical cerclage as part of their standard care. Inclusion criteria include singleton pregnancies and an indication for cervical cerclage for either a history of three or more previous mid-trimester losses or premature births (≤ 28 weeks), insertion of cervical sutures in previous pregnancies, a history of mid trimester loss or premature birth with a (current) shortened (≤ 25 mm) cervix, or women whom clinicians deem to be at risk of preterm birth either by history or the results of an ultrasound scan. Exclusion criteria include women who have taken part in C-STICH previously, are aged less than 18 years old at the time of presentation, require a rescue cerclage, and are unwilling or unable to give informed consent and in whom a cerclage will be placed by any route other than vaginally (e.g. via an abdominal route). Following informed consent, women are randomised on a 1:1 basis to either monofilament or braided suture, by minimisation. The primary outcome is pregnancy loss (miscarriage and perinatal mortality, including any stillbirth or neonatal death in the first week of life), and secondary outcomes include the core outcome set for preterm birth trials.

Discussion

Optimising established interventions to prevent preterm birth is important in reducing perinatal mortality rates.

Trial registration

ISRCTN 15373349. Registered before recruitment on 03 December 2014 prior to first recruit.

Suture thickness and transvaginal cervical cerclage outcomes

Background

Cervical cerclage placement has been shown to benefit women who have cervical insufficiency, however, the best type of suture to use for transvaginal cerclage placement is unknown.

Objective

To evaluate the association between transvaginal cerclage suture thickness and pregnancy outcomes.

Study Design

Retrospective cohort study of women with a singleton, non-anomalous gestation who underwent history-, ultrasound- or physical exam-indicated transvaginal cerclage at a single tertiary care center (2013-2016). The primary outcome was gestational age at delivery. Secondary outcomes included preterm birth less than 34 weeks, chorioamnionitis, neonatal intensive care unit admission and composite neonatal morbidity. Baseline characteristics and outcomes were compared by thickness of suture material: thick 5mm braided polyester fiber (Mersilene® tape) versus thin polyester braided thread (Ethibond®) or polypropylene non-braided monofilament (Prolene®) with selection of suture type at the discretion of the provider. The association between thick suture and gestational age at delivery was estimated using Cox proportional hazard regression. Multivariable logistic regression was used to estimate the association between thick suture and the secondary outcomes. Effect modification of cerclage indication was also assessed.

Results

A total of 203 women met inclusion criteria: 120 (59%) with thick suture and 83 (41%) with thin suture. Of these, 130 women had history-indicated, 35 had ultrasound-indicated, and 38 had exam-indicated cerclages. Compared to women who had thin suture, women with thick suture were more likely to have had a history- or ultrasound-indicated cerclage, rather than exam-indicated cerclage, and more likely to have had a Shirodkar or cervico-isthmic approach, rather than McDonald. Women with thick suture were also more likely to have received progesterone and had placement at earlier gestational age, but there were no differences in cervical exam at placement. After adjusting for confounding factors, thick suture was associated with longer pregnancy duration among women with ultrasound-indicated cerclage (aHR 0.61, 95%CI 0.41-0.91) and exam-indicated cerclage (aHR 0.30, 95%CI 0.15-0.58), but not with history-indicated cerclage (aHR 1.27, 95%CI 0.83-1.94). Thick suture was also associated with lower odds of preterm birth < 34 weeks, chorioamnionitis and neonatal intensive care unit admission, compared to thin suture.

Conclusion

Thick, compared to thin suture, for transvaginal cervical cerclage was associated with longer duration of pregnancy among women with ultrasound- and exam-indicated cerclages and lower odds of chorioamnionitis and neonatal intensive care unit admission among all women regardless of cerclage indication.

Efficacy of different cerclage suture materials in reducing preterm birth

Objective: To compare the efficacy of monofilament suture, braided polyester thread, and 5 mm tape suture in reducing preterm birth (PTB).Study design: Women who received a cerclage at Touro Infirmary, New Orleans, LA, USA, between 1 January, 2011 and 31 December, 2016 were identified using ICD-9/10 codes. All charts were reviewed for demographic and obstetrical variables including gestational age (GA) at delivery.Results: Of 145 women who received a cerclage, 36 were excluded due to incomplete charts leaving 109 for analysis. There was no significant difference in gestational age at cerclage placement or delivery among women with monofilament, braided, or 5 mm tape cerclages (p = .936 and p = .919, respectively) nor was there a difference in the proportion who delivered at ≥32, 34, or 37 weeks across groups with differing cerclage material (p = .270, p = .275, and p = .419, respectively). There was no difference in GA at delivery for patients who received 17-OHP compared to those who did not (p = .362). There were also no differences with respect to birth outcomes such as birthweight (p = .938), Apgar scores (p = .477, p = .430) or neonatal intensive care admission rates (NICU) (p = .304). Analysis revealed no difference in characteristics between groups including history of PTB or indication for removal (p = .371, p = .317).Conclusion: We found no difference in pregnancy prolongation when comparing different suture material used for indicated cerclages. We also found no differences with respect to rates of maternal infection or adverse neonatal outcomes among groups.RationaleThis study was conducted to evaluate the efficacy of different suture materials in increasing gestational age at delivery and reducing preterm birth.

Knot positioning during McDonald cervical cerclage, does it make a difference? A cohort study

Objective: To study the effect of McDonald cerclage knot position on the different maternal and neonatal outcomes. Methods: This historical cohort study included women with singleton pregnancy who had a prophylactic McDonald cervical cerclage between 1 May 2010 and 31 September 2017. Maternal and neonatal outcome parameters were compared between the anterior and posterior knot cerclage procedures. The primary outcome measure was the rate of term birth. Results: 550 Women had a prophylactic McDonald cervical cerclage, 306 with anterior knot (Group A) and 244 with posterior knot (Group B). There were no statistically significant differences regarding gestational age (GA) at delivery (36.3 ± 4.2 versus 35.8 ± 5.3 for groups A and B respectively), term birth rate, post-cerclage cervical length, symptomatic vaginitis, urinary tract infection, difficult cerclage removal and cervical lacerations. Similarly, there were no statistically significant differences as regards the studied neonatal outcomes including take home babies, neonatal intensive care admission, respiratory distress syndrome and neonatal sepsis. Survival analysis on GA at delivery demonstrated no statistically significant difference as regards the proportion of term deliveries in the anterior and posterior knot cerclage groups (log-rank test p-value = .478). Conclusions: Knot positioning during McDonald cervical cerclage, anteriorly or posteriorly, didn't significantly impact the studied maternal and neonatal outcomes.

Pregnant women's preferences for and concerns about preterm birth prevention: a cross-sectional survey

BACKGROUND

Although there is a call for patient-centred prenatal care, women's preferences for and concerns about preterm birth (PTB) prevention have not been well-studied. Therefore, we conducted a cross-sectional survey to determine women's preferences for PTB prevention and their likelihood of following their healthcare provider's recommendations for PTB prevention, as well as factors associated with these responses.

METHODS

A piloted self-administered questionnaire was completed by pregnant women who could read English. Data were collected about their preferences for and concerns about PTB prevention, and the likelihood of following their healthcare provider's recommendations, using multivariable logistic regression to control for other factors.

RESULTS

Three hundred and eleven women at a median of 32-weeks of gestation completed the survey, a response rate of 85.2%. Most women reported that if they were told they were at increased risk for PTB, they preferred not to use PTB prevention (65.8%), of whom almost all (93.4%) reported they preferred close-monitoring and 6.6% preferred neither monitoring nor prevention. A much smaller proportion of women reported that they would not follow their healthcare provider's recommendation for progesterone (10.9%) compared to pessary (28.7%) or cerclage (50.2%). Women who were neither married nor in a common-law relationship were more likely to report that they would not follow recommendations for progesterone (aOR = 5.88 [95% CI: 1.72, 20.00]). Most women (84.5%) reported they would use other sources of information other than their main healthcare provider to learn more about PTB prevention, with the most popular source being the internet.

CONCLUSIONS

Most women reported that if they were told they were at increased risk of PTB, they preferred close-monitoring over using PTB prevention. Their reported likelihood of not following their healthcare provider's recommendations for PTB prevention varied from 10.9% for progesterone to 50.2% for cerclage. These findings suggest that more education about the risk of PTB, PTB preventions, as well as compliance with progesterone is needed and that the internet would be an important source of information. However as our study was completed by women at a median of 32 weeks of gestation, future surveys targeted at women earlier in their pregnancy are needed.

Preterm Birth Prevention Post-Conization: A Model of Cervical Length Screening with Targeted Cerclage

Women with a history of excisional treatment (conization) for cervical intra-epithelial neoplasia (CIN) are at increased risk of preterm birth, perinatal morbidity and mortality in subsequent pregnancy. We aimed to develop a screening model to effectively differentiate pregnancies post-conization into low- and high-risk for preterm birth, and to evaluate the impact of suture material on the efficacy of ultrasound indicated cervical cerclage. We analysed longitudinal cervical length (CL) data from 725 pregnant women post-conization attending preterm surveillance clinics at three London university Hospitals over a ten year period (2004-2014). Rates of preterm birth <37 weeks after targeted cerclage for CL<25mm were compared with local and national background rates and expected rates for this cohort. Rates for cerclage using monofilament or braided suture material were also compared. Of 725 women post-conization 13.5% (98/725) received an ultrasound indicated cerclage and 9.7% (70/725) delivered prematurely, <37weeks; 24.5% (24/98) of these despite insertion of cerclage. The preterm birth rate was lower for those that had monofilament (9/60, 15%) versus braided (15/38, 40%) cerclage (RR 0.7, 95% CI 0.54 to 0.94, P = 0.008). Accuracy parameters of interval reduction in CL between longitudinal second trimester screenings were calculated to identify women at low risk of preterm birth, who could safely discontinue surveillance. A reduction of CL <10% between screening timepoints predicts term birth, >37weeks. Our triage model enables timely discharge of low risk women, eliminating 36% of unnecessary follow-up CL scans. We demonstrate that preterm birth in women post-conization may be reduced by targeted cervical cerclage. Cerclage efficacy is however suture material-dependant: monofilament is preferable to braided suture. The introduction of triage prediction models has the potential to reduce the number of unnecessary CL scan for women at low risk of preterm birth.

Cerclage outcome by the type of suture material (COTS): study protocol for a pilot and feasibility randomised controlled trial

BACKGROUND

Cervical incompetence is one of the causes of preterm birth and mid-trimester pregnancy loss. Cervical cerclage is a surgical procedure to treat cervical incompetence. Cervical cerclage reduces the incidence of preterm birth in women at risk of recurrent preterm birth, without a statistically significant reduction in perinatal mortality or neonatal morbidity. Multifilament/braided sutures such as Mersilene tape have been traditionally used for cervical cerclage. Braided sutures, particularly mesh-like non-absorbable sutures, have been associated with an increased risk of infection and, hence, some obstetricians prefer to use monofilament/non-braided sutures. However, these claims are not substantiated by any scientific or clinical evidence.We propose a pilot/feasibility study which will provide the necessary information for planning a definitive trial investigating the clinical effectiveness of monofilament non-braided suture materials in reducing pregnancy loss rate following cervical cerclage compared to the traditional multifilament braided sutures.

METHODS/DESIGN

Women eligible for elective or ultrasound-indicated cerclage at 12 to 21 + 6 weeks of gestation will be randomised to having the procedure using either a monofilament non-braided suture (Ethilon) or a Multifilament braided suture (Mersilene tape) inserted using a McDonald technique. Consent for participation in the Cerclage outcome by the type of suture (COTS) study will be obtained from each eligible participant.

CLINICAL TRIALS REGISTRATION

COTS is registered with the International Standard Research for Clinical Trials (ISRCTN17866773). Registered on 27 March 2013.