Cerclage position, cervical length and preterm delivery in women undergoing ultrasound indicated cervical cerclage: A retrospective cohort study

Transvaginal cervical cerclage - How well do surgeons assess their own procedures?

INTRODUCTION

In women with cervical incompetence, transvaginal cerclage may help prevent preterm birth. However, training for this procedure poses challenges due to the low number of cases and difficulties in visualizing the operative field. Furthermore, the objective criteria for a successful cerclage procedure are not well-described. Quality assessment relies heavily on self-assessment rather than objective criteria and feedback. To address this issue, training on a simulator may offer a solution. We aimed to objectively assess surgical performance and compare it to the self-assessed performance in transvaginal cerclage procedures.

MATERIALS AND METHODS

During the Nordic Federation of Obstetrics and Gynecology (NFOG) congress in 2023, surgeons proficient in transvaginal cerclage procedures performed a transvaginal cerclage on a simulator. To compare the observed and self-assessed outcomes we obtained measurements on the cerclage height and number of bites from the detachable cervix, and from computed tomography scans we analyzed suture bite depth, reduction of cervix surface area, and whether cerclages had perforated the cervical canal. The same outcomes were self-assessed by each participant after the cerclage procedure. We visualized the continuous paired data in a Bland-Altman plot and compared these data with a paired t-test. Paired binary data was analyzed using McNemars test.

RESULTS

29 participants from eight different nationalities performed one transvaginal cerclage each. The mean height of the cerclage was 26.8 mm (SD 9 mm) and mean depth was 6.5 mm (SD 1.9 mm) across a mean of 4.1 (SD 0.8) bites. The mean reduction of the cervix surface area was 7.6 % (SD 5.9 %). Two sutures perforated the cervical canal. The participants significantly underestimated the height of their cerclage with a mean difference of 6.0 mm (95 % CI 2.1-9.9), (p 0.002), between the observed and the self-assessed height, but otherwise revealed good self-assessment of their performed procedure.

CONCLUSIONS

Overall, the experienced cerclage surgeons showed a genuine insight into their surgical performance of a transvaginal cerclage. These results could warrant development of a procedural guidelines with objective measures, now reassured that surgeons are capable of self-assessing their procedures.

Cervical cerclage: An evolving evidence base

Cervical cerclage is an established intervention for the management of pregnancies at high risk of preterm birth. Although studies exist to support its use in certain situations, particularly in singleton pregnancies, many questions such as adjunct therapies and efficacy in specific subgroups of high-risk women have not been fully elucidated. This review will assess the current evidence as well as areas where there is currently a paucity of data and an urgent requirement for further research.

Changes in cervical elastography, cervical length and endocervical canal width after cerclage for cervical insufficiency: an observational ultrasound study

BACKGROUND

We previously demonstrated that pregnant women with a history of cervical insufficiency had a softer anterior cervical lip, shorter cervical length and wider endocervical canal in the first trimester. The aim of this study was to investigate changes in cervical elastography, cervical length, and endocervical canal width in the second trimester after cerclage, and further discuss whether these ultrasound parameters are predictive of preterm delivery.

METHODS

This was a secondary analysis of cervical changes in singleton pregnancies after cerclage from January 2016 to June 2018. Cervical elastography, cervical length, and endocervical canal width were measured during the second trimester in the cervical insufficiency group and control group without cervical insufficiency. Strain elastography under transvaginal ultrasound was used to assess cervical stiffness and presented as percentage (strain rate).

RESULTS

Among the 339 pregnant women enrolled, 24 had a history of cervical insufficiency and underwent cerclage. Both anterior and posterior cervical lips were significantly softer in the cervical insufficiency group even though they received cerclage (anterior strain rate: 0.18 ± 0.06% vs. 0.13 ± 0.04%; P = 0.001; posterior strain rate: 0.11 ± 0.03% vs. 0.09 ± 0.04%; P = 0.017). Cervical length was also shorter in the cervical insufficiency group (36.3 ± 3.6 mm vs. 38.3 ± 4.6 mm; P = 0.047). However, there was no significant difference in endocervical canal width between the two groups (5.4 ± 0.7 mm vs. 5.6 ± 0.7 mm; P = 0.159). Multivariate logistic regression analysis also revealed significant differences in anterior cervical lip strain rate (adjusted odds ratio [OR], 7.32, 95% confidence interval [CI], 1.70-31.41; P = 0.007), posterior cervical lip strain rate (adjusted OR, 5.22, 95% CI, 1.42-19.18; P = 0.013), and cervical length (adjusted OR, 3.17, 95% CI,1.08-9.29; P = 0.035). Among the four ultrasound parameters, softer anterior cervical lip (P = 0.024) and shorter cervical length (P < 0.001) were significantly related to preterm delivery.

CONCLUSIONS

Cervical cerclage can prevent widening of the endocervical canal, but not improve cervical elasticity or cervical length. Measuring anterior cervical elastography and cervical length may be valuable to predict preterm delivery.

Cervical Cerclage: A Comprehensive Review of Major Guidelines

Importance

Cervical cerclage (CC) represents one of the few effective measures currently available for the prevention of preterm delivery caused by cervical insufficiency, thus contributing in the reduction of neonatal morbidity and mortality rates.

Objective

The aim of this study was to review and compare the most recently published major guidelines on the indications, contraindications, techniques, and timing of placing and removal of CC.

Evidence Acquisition

A descriptive review of guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Royal College of Obstetricians and Gynaecologists (RCOG), the Society of Obstetricians and Gynaecologists of Canada (SOGC), and the International Federation of Gynecology and Obstetrics (FIGO) on CC was carried out.

Results

There is a consensus among the reviewed guidelines regarding the recommended techniques, the indications for rescue CC, the contraindications, as well as the optimal timing of CC placement and removal. All medical societies also agree that ultrasound-indicated CC is justified in women with history of prior spontaneous PTD or mid-trimester miscarriage and a short cervical length detected on ultrasound. In addition, after CC, serial sonographic measurement of the cervical length, bed rest, and routine use of antibiotics, tocolysis, and progesterone are unanimously discouraged. In case of established preterm labor, CC should be removed, according to ACOG, RCOG, and SOGC. Furthermore, RCOG and SOGC agree on the prerequisites that should be met before attempting CC. These 2 guidelines along with FIGO recommend history-indicated CC for women with 3 or more previous preterm deliveries and/or second trimester pregnancy miscarriages, whereas the ACOG suggests the use of CC in singleton pregnancies with 1 or more previous second trimester miscarriages related to painless cervical dilation or prior CC due to painless cervical dilation in the second trimester. The role of amniocentesis in ruling out intra-amniotic infection before rescue CC remains a matter of debate.

Conclusions

Cervical cerclage is an obstetric intervention used to prevent miscarriage and preterm delivery in women considered as high-risk for these common pregnancy complications. The development of universal international practice protocols for the placement of CC seems of paramount importance and will hopefully improve the outcomes of such pregnancies.

Cervical cerclage technique: what do experts actually achieve?

BACKGROUND

Cervical cerclage is a recognized intervention in the management of women at risk of preterm birth and midtrimester loss. The mechanism of action of cerclage is unclear, and the technique has been poorly researched.

OBJECTIVE

This study aimed to evaluate cerclage technique among experienced obstetricians, using a previously developed and evaluated cerclage simulator.

STUDY DESIGN

This prospective experimental simulation and observational study used identical simulators for 28 consultant obstetricians who were asked to perform their normal cerclage. Suture type, height, knot site, and free thread length were recorded. Using computed tomography, depth of bite and tension (by reduction in area of cervix) were calculated.

RESULTS

A total of 52 cervical cerclages were completed (Mersilene tape, n=20; monofilament suture, n=32). Mean suture height was 33 mm (standard deviation, 7.7 mm), greater with monofilament suture than with Mersilene tape, and associated with smaller needle size. Mean depth of bite and mean reduction of starting area did not differ by suture type. Seven procedures showed ≥1 suture bite that had entered the cervical canal once or more.

CONCLUSION

This study assessed cerclage technique of experienced obstetricians using simulators and computed tomography imaging, and demonstrated wide variation in technique; this may affect the efficacy of the procedure. Further work should establish optimal technique and consensus for training and clinical practice.

Longitudinal change in cervical length following vaginal or abdominal cervical cerclage: a randomized comparison

BACKGROUND

Cervical cerclage has been shown to reduce the risk of recurrent spontaneous preterm birth in a high-risk patient population; however, the mechanism is not well understood. Transabdominal cerclage is superior to low and high vaginal cerclage in reducing early spontaneous preterm birth and fetal loss in women with previous failed vaginal cerclage. Cervical length measurements are commonly used to monitor high-risk women and may explain the mechanism of success.

OBJECTIVE

This study aimed to evaluate the rate of change in longitudinal cervical length after randomized placement of low transvaginal, high transvaginal, or transabdominal cerclage in women with a previous failed vaginal cerclage.

STUDY DESIGN

This was a planned analysis of longitudinal transvaginal ultrasound cervical length measurements from patients enrolled in the Vaginal Randomised Intervention of Cerclage trial, a randomized controlled trial comparing transabdominal cerclage or high transvaginal cerclage with low transvaginal cerclage. Cervical length measurements at specific gestational ages were compared over time and between groups, using generalized estimating equations fitted using the maximum-likelihood random-effects estimator. In addition, cervical length measurements were compared in women with transabdominal cerclage placed before and during pregnancy. The diagnostic accuracy of cervical length as a predictor of spontaneous preterm birth at <32 weeks of gestation was explored.

RESULTS

This study included 78 women who underwent longitudinal cervical length assessment (70% of the analyzed cohort) with a history of failed cerclage, of whom 25 (32%) were randomized to low transvaginal cerclage, 26 (33%) to high transvaginal cerclage, and 27 (35%) to transabdominal cerclage. Abdominal cerclage was superior to low (P=.008) and high (P=.001) vaginal cerclage at maintaining cervical length over the surveillance period (14 to 26 weeks of gestation) (+0.08 mm/week, 95% confidence interval, -0.40 to 0.22; P=.580). On average, the cervical length was 1.8 mm longer by the end of the 12-week surveillance period in women with transabdominal cerclage (+1.8 mm; 95% confidence interval, -7.89 to 4.30; P=.564). High vaginal cerclage was no better than low cervical cerclage in the prevention of cervical shortening; the cervix shortened by 13.2 mm over 12 weeks in those with low vaginal cerclage (95% confidence interval, -21.7 to -4.7; P=.002) and by 20 mm over 12 weeks in those with high vaginal cerclage (95% confidence interval, -33.1 to -7.4; P=.002). Preconception transabdominal cerclage resulted in a longer cervix than those performed during pregnancy; this difference was significant after 22 weeks of gestation (48.5 mm vs 39.6 mm; P=.039). Overall, cervical length was an excellent predictor of spontaneous preterm birth at <32 weeks of gestation (receiver operating characteristic curve, 0.92; 95% confidence interval, 0.82-1.00).

CONCLUSION

In women with a previous failed cervical cerclage, in the next pregnancy, the cervical length in women treated with vaginal cerclage funneled and shortened over time, whereas there was preservation of cervical length in women who receive transabdominal cerclage. Cervical length remained longer in transabdominal procedures performed before pregnancy than in transabdominal procedures performed during pregnancy. Overall, cervical length was an excellent predictor of spontaneous preterm birth in our cohort. Our findings may explain the mechanism of benefit for transabdominal cerclage, with its high placement better maintaining the structural integrity of the cervix at the level of the internal os.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of an incompetent mid-second (mid-2nd) trimester absent ecto-cervix: a case series. Cervical amplification pre-cerclage insertion

BACKGROUND

Cervical cerclage is a treatment for an incompetent cervix, the latter being a contributor to spontaneous preterm birth. There is significant difficulty with a transvaginal cerclage insertion for the absent vaginal or ecto-cervix in the mid-2nd trimester period resulting in a higher risk of late miscarriages, extremely preterm labour with increased neonatal morbidity and mortality.

METHODS

A retrospective review of 5 consecutive cases managed by a surgical technique-modified high vaginal cerclage insertion at 18-20 weeks-and adjunct protocols which included vaginal progesterone use, serial infection screening and lifestyle advice, over a 12-month period ending in August 2021, is presented. Inclusion criteria included minimal or absent ecto-cervix, singleton pregnancies with an incompetent cervix attending for a vaginal cerclage whilst exclusion criteria were the usual contraindications to a cerclage insertion. Primary outcome was delivery after 34 weeks whilst seconday outcomes included maternal hemorrhage, bowel/bladder injury, chorioamnionitis and neonatal admission.

RESULTS

A increased gestational latency of 13 gestational weeks (range 12-18). Mean gestational age at delivery was 36 weeks +1 (253 days) with a range of 241-264 days. Delivery after 34 weeks gestational age was 100% with no maternal surgical complications and corresponding neonatal outcomes.

CONCLUSION

There is a potential therapeutic benefit of this technique and adjunct management, in managing an incompetent mid-2nd trimester absent ecto-cervix.

FIGO good practice recommendations on cervical cerclage for prevention of preterm birth

Cervical cerclage is an intervention which when given to the right women can prevent preterm birth and second‐trimester fetal losses. A history‐indicated cerclage should be offered to women who have had three or more preterm deliveries and/or mid‐trimester losses. An ultrasound‐indicated cerclage should be offered to women with a cervical length <25 mm if they have had one or more spontaneous preterm birth and/or mid‐trimester loss. In high‐risk women who have not had a previous mid‐trimester loss or preterm birth, an ultrasound‐indicated cerclage does not have a clear benefit in women with a short cervix. However, for twins, the advantage seems more likely at shorter cervical lengths (<15 mm). In women who present with exposed membranes prolapsing through the cervical os, a rescue cerclage can be considered on an individual case basis, taking into account the high risk of infective morbidity to mother and baby. An abdominal cerclage can be offered in women who have had a failed cerclage (delivery before 28 weeks after a history or ultrasound‐indicated [but not rescue] cerclage). If preterm birth has not occurred, removal is considered at 36–37 weeks in women anticipating a vaginal delivery.

Cervical cerclage given to the right women can prevent preterm birth and second‐trimester fetal losses.

Association of adherence to guidelines for cervical cerclage with perinatal outcomes and placental inflammation in women with cervical length ≥2.0 cm

OBJECTIVES

Cerclage operation is one of the most common obstetric controversies. The aim of this study was to compare the perinatal outcomes and placental inflammation of cerclage performed adherent and non-adherent to international guidelines.

MATERIAL AND METHODS

This study included all consecutive women with singleton deliveries who underwent cerclage. According to the current American College of Obstetricians and Gynecologists (ACOG) guideline, we designated our study population into two groups: the adherent-to-guideline and non-adherent groups. Each group was categorized into two groups according to cervical length (CL) at the time of cerclage (<2.0 cm vs. ≥2.0 cm). We evaluated the reasons for cerclage, maternal characteristics, perioperative variables, pregnancy and neonatal outcomes, and placental inflammatory pathology according to the criteria proposed by the Society of Pediatric Pathology.

RESULTS

Among 310 women with cerclage, we excluded patients (n = 21) with indicated preterm delivery (PTD), major fetal anomaly, fetal death in-utero, and missing information for reason of cerclage. We also excluded patients who underwent physical examination-indicated cerclage (n = 53) and with missing information of CL at the time of cerclage (n = 52). A total of 184 women were eventually analyzed. In women with CL < 2.0 cm, the non-adherent group showed similar PTD (<28 weeks, <34 weeks) and neonatal composite morbidity rates compared to the adherent-to-guideline group. However, in women with CL ≥ 2.0 cm, the non-adherent group manifested significantly higher PTD (<28 weeks; 16.7% vs. 4.4%, p = 0.04, <34 weeks; 23.8% vs. 5.8%, p = 0.006) and neonatal composite morbidity (20.5% vs. 5.9%, p = 0.028) rates than the adherent-to-guideline group despite similar perioperative variables and lower PTD history rates. The non-adherent group with CL ≥ 2 cm at the time of cerclage was also associated with severe histologic chorioamnionitis (p = 0.033).

CONCLUSION

Cerclage performed beyond the current guidelines in pregnant women with CL ≥ 2.0 cm may confer an additional risk of perinatal complications in association with severe placental inflammation.

Shirodkar cerclage: Obstetrical and neonatal outcomes in a single-center cohort of 55 cases

BACKGROUND

Cervical insufficiency is thought to be responsible for 10% of preterm deliveries. Shirodkar cerclage is among the available techniques ranging from McDonald's to definitive procedures, however the indications for the prevention of preterm births and mid-trimester miscarriages are still poorly delineated.

OBJECTIVE

To describe the characteristics, obstetrical and neonatal outcomes of pregnancies with Shirodkar cerclage procedures.

METHOD

We performed a descriptive retrospective single-center study, including all patients who had a Shirodkar cerclage between January 1, 2008 and December 31, 2020. The main outcomes measured were delivery at or beyond 24 and 32 weeks of gestations (WG).

RESULTS

55 Shirodkar cerclages were performed over the period studied. 7.3% of patients had a uterine malformation, 9% had a history of cervical conization. 74.5% had history of one or more mid-trimester miscarriages. 63.6% had a history of a failed emergency or prophylactic cerclage. The median gestational age (GA) at cerclage placement was 14 WG. There were 4 deliveries before 24 WG, 8 before 32 WG and 16 before 37 WG. Overall neonatal survival was 48/53 (90.6%). The median GA at delivery was 38 weeks (IQR 35-39), with 70.3% of vaginal deliveries.

CONCLUSION

Shirodkar cerclage was successful in more than 90% of patients, despite their obstetric history. Shirodkar cerclage may be indicated in the event of prior cerclage failure using the McDonald technique or in order to allow for correct stitch placement in very short cervixes. Its advantage over definitive cerclage is to allow for vaginal delivery.

The association between sonographic cervical length components and preterm birth in women with ultrasound- or exam-indicated cerclage

OBJECTIVE

To evaluate which parameters of a sonographic cervical length measurement are associated with preterm birth in women with ultrasound- or exam-indicated cerclage.

METHODS

This was a retrospective cohort study of women with singleton pregnancies who underwent ultrasound- or exam-indicated Shirodkar cerclage by a single maternal-fetal medicine practice between 2011 and 2019. All patients underwent sonographic cervical length measurement 2-3 weeks after cerclage placement, and then every 2-4 weeks up to 32 weeks. The images from the first and second post-cerclage cervical lengths were reviewed. Total cervical length, upper cervical length (from the internal cervical os to the cerclage), and lower cervical length (from the cerclage to the external os) were measured. The primary outcome for this study was gestational age at delivery.

RESULTS

A total of 114 women with cerclage were included (85 (74.6%) ultrasound-indicated and 29 (25.4%) exam-indicated). The first and second total cervical lengths correlated with gestational age at delivery (r = 0.26, p=.005; r = 0.33, p<.001, respectively), and the change from first to second was inversely correlated with gestational age at delivery (r = -0.20, p=.032). The first and second upper cervical lengths also correlated with gestational age at delivery (r = 0.22, p = .019; r = 0.33, p<.001, respectively), and the change from first to second upper cervical length was inversely correlated with gestational age at delivery (r= -0.20, r = 0.029). Neither the first nor the second lower cervical lengths were significantly associated with gestational age at delivery. On regression analysis, total cervical length and upper cervical length were not independently associated with gestational age at delivery (p = .108 and p=.806, respectively, for the first scan; p = .153 and p=.166, respectively, for the second scan).

CONCLUSIONS

Postcerclage total cervical length and upper cervical length are both associated with gestational age at delivery and risk of preterm birth, but not independently. After ultrasound- or exam-indicated cerclage, sonographic monitoring of either the total cervical length or the upper cervical length might be predictive of gestational age at delivery and the risk of preterm birth.

Factors associated with preterm birth in women undergoing cervical cerclage

OBJECTIVES

Cervical cerclage is used to manage women at high risk of late miscarriage (LM) and spontaneous preterm birth (PTB) due to factors such as history of cervical insufficiency (CI), uterine anomaly, cervical surgery and ultrasound (US) diagnosed cervical shortening. Urinary tract infection (UTI) and subsequent pyelonephritis, and bacterial infection are associated with PTB, but their role in PTB after cervical cerclage is unknown. We examined the relationship between UTI and bacterial vaginosis (BV), fetal fibronectin (fFN) test and PTB in women undergoing elective- or US-indicated cervical cerclage. We also investigated whether fetal fibronectin (fFN) test were useful to predict PTB.

STUDY DESIGN

This is a single center, retrospective study of singleton pregnant women at PTB clinic, University College London Hospital (UCLH, 2005-2015) who underwent elective or US-indicated cervical cerclage. Women were tested for UTI and BV before cerclage placement and received mid-gestation fFN testing. Patient data were extracted from the PTB clinic database and electronic records. Statistical analyses used Pearson's chi-square and Mann-Whitney U tests. P values were corrected by Bonferroni method as required.

RESULTS

267 singleton pregnant women attended our clinic with completed birth outcome. Of those, 32.2% (86/267) delivered prematurely. All women with UTI or BV received antibiotic treatment. Women with a UTI before cerclage placement were more likely to deliver preterm when compared to those with negative MSU culture (OR 3.39, 95%CI 1.24-9.27, p = 0.04). Their gestational age at delivery were also lower than those with negative MSU result (36⁺⁶, IQR 31⁺⁴-38⁺²week vs 38⁺¹, IQR 36⁺¹-39⁺⁵-week, p = 0.05). However, UTI after cerclage placement or BV either before or after cerclage placement were not associated with PTB. Women who had a positive fFN result were more likely to deliver preterm (OR 3.85, 95% CI 1.81-8.41, p = 0.0007).

CONCLUSIONS

The presence of a UTI before cervical cerclage is associated with a higher rate of PTB in women who receive a cervical cerclage, even when treated. We did not find an association between pre or post-cerclage BV or post-cerclage UTI and PTB. Further research is needed to elucidate the link between UTI and PTB in women undergoing cervical cerclage.

MAVRIC: a multicenter randomized controlled trial of transabdominal vs transvaginal cervical cerclage

BACKGROUND

Vaginal cerclage (a suture around the cervix) commonly is placed in women with recurrent pregnancy loss. These women may experience late miscarriage or extreme preterm delivery, despite being treated with cerclage. Transabdominal cerclage has been advocated after failed cerclage, although its efficacy is unproved by randomized controlled trial.

OBJECTIVE

The objective of this study was to compare transabdominal cerclage or high vaginal cerclage with low vaginal cerclage in women with a history of failed cerclage. Our primary outcome was delivery at <32 completed weeks of pregnancy.

STUDY DESIGN

This was a multicenter randomized controlled trial. Women were assigned randomly (1:1:1) to receive transabdominal cerclage, high vaginal cerclage, or low vaginal cerclage either before conception or at <14 weeks of gestation.

RESULTS

The data for 111 of 139 women who were recruited and who conceived were analyzed: 39 had transabdominal cerclage; 39 had high vaginal cerclage, and 33 had low vaginal cerclage. Rates of preterm birth at <32 weeks of gestation were significantly lower in women who received transabdominal cerclage compared with low vaginal cerclage (8% [3/39] vs 33% [11/33]; relative risk, 0.23; 95% confidence interval, 0.07-0.76; P=.0157). The number needed to treat to prevent 1 preterm birth was 3.9 (95% confidence interval, 2.32-12.1). There was no difference in preterm birth rates between high and low vaginal cerclage (38% [15/39] vs 33% [11/33]; relative risk, 1.15; 95% confidence interval, 0.62-2.16; P=.81). No neonatal deaths occurred. In an exploratory analysis, women with transabdominal cerclage had fewer fetal losses compared with low vaginal cerclage (3% [1/39] vs 21% [7/33]; relative risk, 0.12; 95% confidence interval, 0.016-0.93; P=.02). The number needed to treat to prevent 1 fetal loss was 5.3 (95% confidence interval, 2.9-26).

CONCLUSION

Transabdominal cerclage is the treatment of choice for women with failed vaginal cerclage. It is superior to low vaginal cerclage in the reduction of risk of early preterm birth and fetal loss in women with previous failed vaginal cerclage. High vaginal cerclage does not confer this benefit. The numbers needed to treat are sufficiently low to justify transabdominal surgery and cesarean delivery required in this select cohort.

Beyond Cervical Length: Association between Postcerclage Transvaginal Ultrasound Parameters and Preterm Birth

OBJECTIVE

To assess the value of transvaginal ultrasound parameters after cerclage placement in estimating the risk of spontaneous preterm birth.

STUDY DESIGN

This is a retrospective cohort at a single tertiary care center from 2013 to 2016. Women carrying a singleton, nonanomalous fetus with cerclage in situ and at least one postcerclage transvaginal ultrasound from 16^0/7 to 25^6/7 weeks' gestation were included. In addition to abstracting maternal demographic and obstetric characteristics, two study investigators separately reviewed each of the images from the first transvaginal ultrasound after cerclage placement, masked to pregnancy outcomes. We measured the angle between the anterior uterine wall and cervical canal at the internal os and external os, closed canal length above and below the stitch, width of the anterior and posterior cervix at the level of the cerclage, and stitch distance from the cervical canal. The presence of additional ultrasound findings such as sludge and cervical funneling was also noted. The main outcomes were preterm birth < 34 weeks and preterm birth < 37 weeks. Transvaginal ultrasound parameters were compared between women with preterm birth and those without preterm birth using chi-square, Fisher's exact, and Wilcoxon's rank-sum tests, as appropriate. Log binomial regression was used to estimate the relative risk of preterm birth for all significant obstetric and ultrasound characteristics.

RESULTS

A total of 102 women met inclusion criteria: 58% had history-indicated, 20% ultrasound-indicated, and 23% exam-indicated cerclages. Of these, 28 (27.5%) women delivered at < 34 weeks' gestation, and 48 (47.0%) women delivered at < 37 weeks' gestation. Preterm birth did not vary by race, maternal age, insurance, smoking, or gestational age of the earliest prior preterm birth (for multiparous women), but women who had preterm birth were more likely to have exam-indicated cerclage. There were several transvaginal ultrasound parameters associated with preterm birth < 34 weeks and preterm birth < 37 weeks. Of these, cervical length below the stitch, stitch distance from the cervical canal, straight cervical canal, funneling to or past the stitch, and presence of sludge had the greatest effect sizes.

CONCLUSION

Rates of preterm birth are high postcerclage. In addition to measuring cervical length, utilization of postcerclage transvaginal ultrasound to evaluate the location of the cerclage within the cervix, the curvature of the cervical canal, and the presence of funneling and sludge may help identify women who are at the highest risk for preterm birth.

Preconception laparoscopic transabdominal cervical cerclage for the prevention of midtrimester pregnancy loss and preterm birth: a single centre experience

BACKGROUND

A recent Cochrane review concluded that cervical cerclage reduces preterm birth before 37, 34 and 28 weeks of gestation and also probably reduces the risk of perinatal death. Transabdominal cerclage was developed for a subgroup in whom transvaginal cerclage had failed or was not possible. This approach appeared more effective in improving foetal survival rates or obstetric outcomes. Most commonly transabdominal cervical cerclage is placed at laparotomy (open transabdominal cerclage), but with the advance of minimal access techniques, laparoscopic transabdominal cervical cerclage is replacing the traditional open operation. The objective of this prospective case series is to explore the outcomes of pre-conception laparoscopic transabdominal cerclage procedures.

METHOD

Data was prospectively collected from 54 women at high risk of second trimester miscarriage and preterm delivery due to cervical insufficiency undergoing pre-conception laparoscopic transabdominal cerclage by a single operator. This included demographics, obstetric and gynaecological history (including previous cervical cerclage procedures), surgical complication rates, conception and subsequent pregnancy outcomes.

RESULTS

There were 36 pregnancies progressing beyond the first trimester with a "take home baby" rate of 89% (32/36), a live birth rate of 92% (33/36) and neonatal survival rate of 97% (32/33). The mid-trimester loss (MTL) rate was 8% (3/36) with delivery rates after 37 weeks of 75% (27/36) and between 34 -37 weeks of 8% (3/36) and 23-34 weeks of 8% (3/36).

CONCLUSIONS

Our prospective case series provides further evidence that laparoscopic transabdominal cerclage (TAC) is feasible, safe and effective when transvaginal cerclage fails or is not possible.

Cervical length, cervical dilation, and gestational age at cerclage placement and the risk of preterm birth in women undergoing ultrasound or exam indicated Shirodkar cerclage

Background: Preterm birth is a major cause of neonatal morbidity and mortality in the USA. In many patients at risk for preterm birth, cervical length (CL) screening is used to guide decisions regarding cerclage placement. Quality evidence shows that cerclage prolongs pregnancy in high-risk women with a short CL in women with a history of preterm birth and in women with painless cervical dilation in the second trimester, though the degree of cervical shortening, dilation, or gestational age at cerclage placement are not consistently associated with the subsequent rate of preterm birth. Our objective was to determine if cervical length (CL), cervical dilation or gestational age (GA) at the time of cerclage placement are associated with preterm birth among women undergoing ultrasound-indicated or exam-indicated cerclage.Study design: This was a retrospective cohort study of all patients with a singleton pregnancy who underwent ultrasound-indicated or exam-indicated Shirodkar cerclage placement at a single maternal-fetal medicine practice in New York City between November 2005 and May 2017. All patients included in the study had previously undergone CL screening for an increased risk of preterm birth (for example, prior spontaneous preterm birth or mid-trimester loss, prior cervical excision). The cervical length or dilation and GA at the time of cerclage placement were collected, as were demographic and obstetric outcome data for the current pregnancy. The primary outcome was delivery <36 or ≥36 weeks. Planned subgroup analyses of the primary outcome were performed based on CL at the time of ultrasound-indicated cerclage (0-9 mm, 10-19 mm, ≥20 mm), cervical dilation at the time of physical exam-indicated cerclage (<2 cm vs. ≥2 cm), and gestational age at cerclage placement (<20 weeks vs. ≥20 weeks). Data were analyzed using the Student's t-test and chi-square test for trend.Results: There were 123 and 39 patients in the ultrasound- and exam-indicated cerclage groups, respectively. Twenty six (21.2%) patients in the ultrasound-indicated subgroup and 24 patients (61.5%) in the exam-indicated subgroup delivered <36 weeks. CL (16.4 versus 17.6 mm, p = .28) and GA (19.7 versus 20.0 weeks, p = .58) at the time of ultrasound-indicated cerclage placement were not significantly different in patients who delivered <36 and ≥36 weeks' gestation, respectively. Women with cervical dilation ≥2 cm prior to exam-indicated cerclage placement were significantly more likely to deliver <36 weeks when compared to women with cervical dilation <2 cm (77.8 versus 47.6%, p = .05); however, there were no significant differences in rates of preterm birth <28 and <32 weeks between these two groups (38.9 versus 23.8%, p = .31 and 50.0% versus 28.6%, p = .17, respectively).Conclusions: Cervical length and GA at the time of ultrasound-indicated Shirodkar cerclage placement do not appear to impact the likelihood of preterm birth <36 weeks, while cervical dilation ≥2 cm at the time of exam-indicated Shirodkar cerclage is associated with an increased rate of preterm birth <36 weeks, but not earlier gestational ages at delivery.

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.