Cervical cerclage for prevention of preterm delivery in women with short cervix: randomised controlled trial

[Primary and secondary cerclage in high-risk pregnant women: Influence on prolongation of pregnancy and preterm birth]

INTRODUCTION

The aim of the study was to evaluate the effectiveness of cerclage in women with previous late miscarriages or premature births. The primary aim was to prolong pregnancy and achieve a term delivery. Secondarily, it was investigated whether an intervention after an early pathological 75-g-oGTT result influences these endpoints.

METHODS

A total of 133 cases were analyzed retrospectively. 80 women underwent primary cerclage between the 14th and 16th week of pregnancy; 53 women underwent secondary cerclage after cervical shortening of less than 25 mm. This group was further subdivided into therapeutic and emergency cerclage groups. Women with early pathologic 75-g-oGTT were treated diabetologically.

RESULTS

Primary cerclage prolonged pregnancy by 20.6 weeks and led to a term delivery in 51 women (63.8%). In the group with secondary cerclage, 25 women (47.2%) had a term delivery with a prolongation of 20.1 weeks. For amniotic sac prolapse, the prolongation was 7.9 weeks. Pathological 75-g-oGTT results were found in 63 women. Early intervention had no significant effect on prolongation and term delivery.

CONCLUSION

Primary cerclage was more effective in achieving term delivery. Women with therapeutic cerclage without amniotic sac prolapse also benefited. With cervical shortening without prolapse, the prolongation was the same in both groups. The worst outcome was observed in emergency cerclage with amniotic sac prolapse. An early 75-g-oGTT is important in order to recognize and treat gestational diabetes in time.

Management of cervical cerclage after preterm premature rupture of membranes: an argument for removal

Cervical cerclage is a widely used intervention to prevent preterm birth in high-risk pregnancies. However, cerclage is associate with risks, including preterm premature rupture of membranes and subsequent complications, such as chorioamnionitis. Our review evaluates the evidence for immediate removal (ie, removal at the time of diagnosis) vs retention of cervical cerclage (ie, removal when clinically indicated) after preterm premature rupture of membranes, focusing on optimizing neonatal outcomes and minimizing maternal and fetal complications. A meta-analysis on the topic that included 169 patients in the "removal" group and 208 in the "retention" group showed that the rates of pregnancy prolongation >48 hours and >7 days were significantly lower in the group who underwent immediate removal of cerclage than in the group who had delayed removal of cerclage (pregnancy prolongation >48 hours: 47% vs 85%, respectively; odds ratio, 0.15; pregnancy prolongation >7 days: 33% vs 57%, respectively; odds ratio, 0.30). In addition, pregnancy latency was significantly lower, despite the absolute mean difference being only 2.84 days. However, the rates of chorioamnionitis and Apgar score <7 at 5 minutes were significantly lower in the immediate removal group than in the retention group (chorioamnionitis: 29% vs 41%, respectively; odds ratio, 0.57; Apgar score <7 at 5 minutes: 16% vs 43%, respectively; odds ratio, 0.22). A proposed balanced approach involves retaining the cerclage for approximately 24 hours after premature rupture of membranes (PROM) to permit steroid administration (initial dose followed by a second dose after 24 hours) before removal. This strategy aims to maximize steroid benefits while minimizing the risks of prolonged cerclage retention, potentially achieving a correct timing that optimizes neonatal outcomes without significantly increasing complications This management approach could be beneficial in situations where immediate removal may preclude full steroid benefits. Our recommendations support a protocol balancing appropriate timing for steroid administration with the risks of extended cerclage retention, namely, chorioamnionitis, unless further randomized controlled trials will show the proper evidence-based management in this clinical scenario.

Efficacy of ultrasound-indicated cerclage without prior preterm birth

AIM

Our study aimed to evaluate the effectiveness of ultrasound-indicated cerclage in singleton pregnancies with cervical shortening (<25 mm), excluding those with a history of preterm birth (PTB) and infection/inflammation.

MATERIALS AND METHODS

Among the 1556 women admitted for a cervix measuring <25 mm via transvaginal ultrasound at Juntendo University Urayasu Hospital between January 2001 and December 2023, our study focused on 47 singleton patients with no prior history of PTB. After receiving information on both risks and benefits, 25 patients opted for ultrasound-indicated cerclage (cerclage group), while 22 chose expectant management (expectant management group). All participants underwent screening for infection/inflammation of the lower genital tract. The primary outcome, the rate of PTB (<37 weeks', <34 weeks', and <28 weeks' gestation), was assessed in both groups.

RESULTS

The cerclage group demonstrated a significantly lower rate of PTB before 37 and 34 weeks' gestation. Although there was no statistically significant difference, the cerclage group exhibited a delay of 3.6 weeks in the average week of gestation compared to the expectant management group. Notably, the hospitalization period in the cerclage group was significantly reduced by 42 days.

CONCLUSION

Performing an ultrasound-indicated cerclage in cases of a short cervical length <25 mm without a prior history of PTB and infection/inflammation reduces the rates of PTB (<37 and <34 weeks' gestation) and hospitalization period.

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.

Predictors of preterm birth following emergency and ultrasound-indicated cervical cerclage: A retrospective study on 136 singleton pregnancies

OBJECTIVE

We aimed to retrospectively evaluate obstetric and neonatal outcomes in patients who underwent ultrasound-indicated and rescue cervical cerclage and to identify predictors for cerclage failure and consequent preterm birth (PTB).

MATERIALS AND METHODS

We conducted a retrospective analysis on singleton pregnancies between 16 and 27 weeks of gestation who presented with a transvaginal sonographic cervical length (TVS-CL) <25 mm and a previous PTB/second-trimester miscarriage or prolapsed amniotic membranes and/or a TVS-CL <15 mm and underwent cervical cerclage at Mangiagalli Center, Milan, between September 2011 and December 2021. Univariate and multivariate logistic regression analyses were used to identify possible predictive factors of cerclage failure.

RESULTS

During the study period, a total of 136 singletons met the inclusion criteria. Overall, 3 % of pregnancies did not reach fetal viability, mostly due to post-cerclage preterm premature rupture of membranes and/or chorioamnionitis. The mean gestational age at delivery was 35.9 ± 4.5 weeks. Neonates were delivered beyond 37 weeks in 63.2 % of cases, between 28 and 37 weeks in 26.5 %, and less than 28 gestational weeks in 10.3 %. At the multivariate analysis, independent risk factors for miscarriage or PTB were cervical length <10 mm (odds ratio, OR 3.44), advanced cervical dilatation (OR 4.76), and in vitro fertilization (OR 4.66). A history of previous miscarriage, premature delivery, and uterine malformations did not increase the risk of post-cerclage delivery before 37 weeks. In the preterm delivery group, 14 % of patients experienced preterm premature rupture of membranes (pPROM) and 10 % had chorioamnionitis, while no case was registered in the term delivery group. A positive vaginal swab at the time of cervical cerclage was not significantly associated with PTB at the multivariate analysis but it emerged as a significant risk factor for both chorioamnionitis (OR 11.03) and pPROM (OR 5.28).

CONCLUSIONS

Ultrasound-indicated and rescue cervical cerclage were effective in prolonging pregnancy, even when placed beyond 24 weeks of gestation. Preoperative cervical length of less than 10 mm, advanced dilatation, and in vitro fertilization are associated with an increased risk of cerclage failure. A positive vaginal swab before cerclage is associated with increased rates of intrauterine infectious-inflammatory processes.

Rate of preterm delivery and latency period in asymptomatic patients undergoing cerclage for very short cervix ≤10.0 mm

BACKGROUND

In asymptomatic women with cervical length ≤10 mm, vaginal progesterone has a limited effect in reducing the rate of preterm delivery.

OBJECTIVE

This study aimed to estimate the rate of preterm delivery and mean latency period to delivery in asymptomatic women with no history of preterm delivery and a cervical length of ≤10.0 mm undergoing or not undergoing cerclage and who were not treated with vaginal progesterone.

STUDY DESIGN

This was a retrospective analysis of asymptomatic patients with singleton pregnancies and no history of preterm delivery with an incidental finding of a cervical length of ≤10.0 mm measured by transvaginal ultrasound during midtrimester scan. Of note, 56 patients (63.6%) underwent cerclage placement and 32 patients (36.4%) did not, none of them received vaginal progesterone. Patients with evidence of advanced dilation, prolapsing membranes, ruptured membranes, or positive signs of infection were not candidates for cerclage placement and were excluded from the analysis. Differences in the prevalence of preterm delivery, mean gestational age at delivery, and mean latency from very short cervix identification to delivery between the 2 groups were calculated. Associations between cerclage and preterm delivery adjusted for maternal characteristics and fetal weight were estimated.

RESULTS

The median gestational ages at the time of cervical length measurement were 20 6/7 weeks (interquartile range, 17 5/7 to 23 3/7) in the cerclage group and 21 5/7 weeks (interquartile range, 17 6/7 to 23 6/7) in the no-cerclage group (P=.02). No difference in cervical length was observed between patients who had a cerclage (5.9±3.1 mm) and those who did not have a cerclage (6.5±3.2 mm) (P=.4). The prevalence of preterm delivery in women with cerclage vs women without cerclage was as follows: PTD at <37 weeks of gestation (31/56 [55.3%] in the cerclage group vs 28/32 [87.5%] in the no-cerclage group; adjusted odds ratio, 0.17; 95% confidence interval, 0.05-0.62; P=.008), PTD at ≤34 weeks of gestation (27/56 [48.2%] in the cerclage group vs 24/32 [75.0%] in the no-cerclage group; adjusted odds ratio, 0.16; 95% confidence interval, 0.05-0.55; P=.02), and PTD at ≤28 weeks of gestation (19/56 [33.9%] in the cerclage group vs 22/32 [68.7%] in the no-cerclage group; adjusted odds ratio, 0.15; 95% confidence interval, 0.05-0.51; P=.002). The median gestational ages at delivery were 32 6/7 weeks (interquartile range, 19 1/7 to 40 1/7) in the cerclage group and 28 1/7 weeks (interquartile range, 20 1/7 to 40 2/7) in the no-cerclage group (P=.001). The median latencies from the time of cervical length measurement to delivery were 84 days (interquartile range, 8-144) in the cerclage group and 43 days (interquartile range, 1-146) in the no-cerclage group (P=.003).

CONCLUSION

Among low-risk asymptomatic women with a very short cervix (≤10.0 mm) in the midtrimester of pregnancy, women treated with cerclage have an increased latency to delivery and a lower prevalence of preterm delivery than those treated with expectant management.

Cerclage Plus Adjuvant Vaginal Progesterone for Preterm Birth Prevention in Patients with a Short or Dilated Cervix without Prior Preterm Birth

OBJECTIVE

 The primary objective was to determine if vaginal progesterone following cerclage for cervical length <10 mm or cervical dilation in patients without a history of spontaneous preterm birth (sPTB) decreased the risk of preterm birth at <34 weeks' gestation compared with cerclage alone. Secondary objectives were to determine if vaginal progesterone following cerclage (1) decreased the risk of preterm birth at <24, <28, and <37 weeks' gestation and (2) increased the latency period from cerclage placement to delivery compared with treatment with cerclage alone.

STUDY DESIGN

 Multicenter retrospective cohort study from 2015 to 2020 of singleton pregnancies, without prior sPTB, who had cerclage placement <24 weeks' gestation for cervical length <10 mm or cervical dilation. Exposure defined as cerclage plus vaginal progesterone postoperatively (dual therapy) and unexposed as cerclage alone (monotherapy), based on surgeon preference.

RESULTS

 We included 122 patients, 78 (64%) treated with dual therapy and 44 (36%) treated with monotherapy. In the crude analysis, dual therapy was associated with a lower risk of delivery at <28 weeks' gestation (13%) compared with monotherapy (34%; crude risk ratio: 0.38 [95% confidence interval (CI): 0.19-0.75]). When adjusted for preoperative vaginal progesterone, results were attenuated (adjusted risk ratio: 0.45 [95% CI: 0.20-1.01]). In both the crude and adjusted analyses, the risk of sPTB was not statistically different at <24, <34 or <37 weeks' gestation. Dual therapy was associated with a greater pregnancy latency from cerclage to delivery (16.3 vs. 14.4 weeks; p = 0.04), and greater gestational age at delivery (37.3 vs. 35.8 weeks' gestation; p = 0.02) compared with monotherapy.

CONCLUSION

 While not statistically significant, the risk of sPTB was lower at all gestational ages studied in patients treated with dual therapy compared with monotherapy. Dual therapy was associated with longer pregnancy latency and greater gestational age at delivery compared with monotherapy.

KEY POINTS

· Dual therapy did not decrease preterm birth risk compared with monotherapy.. · Dual therapy prolonged pregnancy compared with monotherapy.. · Dual therapy can be considered but further studies are needed..

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).

Comparing cervical cerclage, pessary and vaginal progesterone for prevention of preterm birth in women with a short cervix (SuPPoRT): A multicentre randomised controlled trial

BACKGROUND

Cervical cerclage, cervical pessary, and vaginal progesterone have each been shown to reduce preterm birth (PTB) in high-risk women, but to our knowledge, there has been no randomised comparison of the 3 interventions. The SuPPoRT "Stitch, Pessary, or Progesterone Randomised Trial" was designed to compare the rate of PTB <37 weeks between each intervention in women who develop a short cervix in pregnancy.

METHODS AND FINDINGS

SuPPoRT was a multicentre, open label 3-arm randomised controlled trial designed to demonstrate equivalence (equivalence margin 20%) conducted from 1 July 2015 to 1 July 2021 in 19 obstetric units in the United Kingdom. Asymptomatic women with singleton pregnancies with transvaginal ultrasound cervical lengths measuring <25 mm between 14+0 and 23+6 weeks' gestation were eligible for randomisation (1:1:1) to receive either vaginal cervical cerclage (n = 128), cervical pessary (n = 126), or vaginal progesterone (n = 132). Minimisation variables were gestation at recruitment, body mass index (BMI), and risk factor for PTB. The primary outcome was PTB <37 weeks' gestation. Secondary outcomes included PTB <34 weeks', <30 weeks', and adverse perinatal outcome. Analysis was by intention to treat. A total of 386 pregnant women between 14+0 and 23+6 weeks' gestation with a cervical length <25 mm were randomised to one of the 3 interventions. Of these women, 67% were of white ethnicity, 18% black ethnicity, and 7.5% Asian ethnicity. Mean BMI was 25.6. Over 85% of women had prior risk factors for PTB; 39.1% had experienced a spontaneous PTB or midtrimester loss (>14 weeks gestation); and 45.8% had prior cervical surgery. Data from 381 women were available for outcome analysis. Using binary regression, randomised therapies (cerclage versus pessary versus vaginal progesterone) were found to have similar effects on the primary outcome PTB <37 weeks (39/127 versus 38/122 versus 32/132, p = 0.4, cerclage versus pessary risk difference (RD) -0.7% [-12.1 to 10.7], cerclage versus progesterone RD 6.2% [-5.0 to 17.0], and progesterone versus pessary RD -6.9% [-17.9 to 4.1]). Similarly, no difference was seen for PTB <34 and 30 weeks, nor adverse perinatal outcome. There were some differences in the mild side effect profile between interventions (vaginal discharge and bleeding) and women randomised to progesterone reported more severe abdominal pain. A small proportion of women did not receive the intervention as per protocol; however, per-protocol and as-treated analyses showed similar results. The main study limitation was that the trial was underpowered for neonatal outcomes and was stopped early due to the COVID-19 pandemic.

CONCLUSIONS

In this study, we found that for women who develop a short cervix, cerclage, pessary, and vaginal progesterone were equally efficacious at preventing PTB, as judged with a 20% equivalence margin. Commencing with any of the therapies would be reasonable clinical management. These results can be used as a counselling tool for clinicians when managing women with a short cervix.

TRIAL REGISTRATION

EU Clinical Trials register. EudraCT Number: 2015-000456-15, clinicaltrialsregister.eu., ISRCTN Registry: ISRCTN13364447, isrctn.com.

Prediction of Preterm Delivery among Low-risk Indian Pregnant Women: Discriminatory Power of Cervical Length, Serum Ferritin, and Serum Alpha-fetoprotein

Background

Around 80% of preterm births (PTBs) occur spontaneously. Various biomarkers are being evaluated to assess the possible role of chorioamniotic inflammation in PTBs.

Aim

The aim of this study was to establish the accuracy of serum bio-markers( cut off values of ferritin and alpha-fetoprotein [AFP] at midtrimester) along with cervical length [CL] assessment to predict preterm delivery among low-risk women.

Methods

Three hundred low-risk pregnant women attending the antenatal clinic of a tertiary health care facility were included and underwent CL measurement during mid-trimester by transvaginal ultrasonography and their serum levels of ferritin and AFP were recorded. All were followed up till delivery.

Results

Receptor-operated characteristic curves for ferritin, AFP, and CL were constructed. Area under curves and Youden Index calculated for each marker were very low (<0.5) which is statistically considered very poor for a screening test.

Conclusion

Serum ferritin and AFP together with CL measurement in the second trimester of pregnancy had poor discriminatory value in predicting preterm delivery among low-risk asymptomatic pregnant women.

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.

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.

Different effects for different questions: An illustration using short cervix and the risk of preterm birth

OBJECTIVE

To illustrate the difference between exposure effects and population attributable effects.

METHODS

We examined the effect of mid-pregnancy short cervical length (<25 mm) on preterm birth using data from a prospective cohort of pregnant women in Lusaka, Zambia. Preterm birth was live birth or stillbirth before 37 weeks of pregnancy. For estimation, we used multivariable regression and parametric g-computation.

RESULTS

Among 1409 women included in the analysis, short cervix was rare (2.4%); 13.6% of births were preterm. Exposure effect estimates were large (marginal risk ratio 2.86, 95% confidence interval [CI] 1.80-4.54), indicating that the preterm birth risk was substantially higher among women with a short cervix compared with women without a short cervix. However, the population attributable effect estimates were close to the null (risk ratio 1.06, 95% CI 1.02-1.10), indicating that an intervention to counteract the impact of short cervix on preterm birth would have minimal effect on the population risk of preterm birth.

CONCLUSION

Although authors often refer to "the" effect, there are actually different types of effects, as we have illustrated here. In planning research, it is important to consider which effect to estimate to ensure that the estimate aligns with the research objective.

Progesterone, cerclage, pessary, or acetylsalicylic acid for prevention of preterm birth in singleton and multifetal pregnancies - A systematic review and meta-analyses

Background

Preterm birth is the leading cause of childhood mortality and morbidity. We aimed to provide a comprehensive systematic review on randomized controlled trials (RCTs) on progesterone, cerclage, pessary, and acetylsalicylic acid (ASA) to prevent preterm birth in asymptomatic women with singleton pregnancies defined as risk of preterm birth and multifetal pregnancies.

Methods

Six databases (including PubMed, Embase, Medline, the Cochrane Library) were searched up to February 2022. RCTs published in English or Scandinavian languages were included through a consensus process. Abstracts and duplicates were excluded. The trials were critically appraised by pairs of reviewers. The Cochrane risk-of-bias tool was used for risk of bias assessment. Predefined outcomes including preterm birth, perinatal/neonatal/maternal mortality and morbidity, were pooled in meta-analyses using RevMan 5.4, stratified for high and low risk of bias trials. The certainty of evidence was assessed using the GRADE approach. The systematic review followed the PRISMA guideline.

Results

The search identified 2,309 articles, of which 87 were included in the assessment: 71 original RCTs and 16 secondary publications with 23,886 women and 32,893 offspring. Conclusions were based solely on trials with low risk of bias (n = 50).Singleton pregnancies: Progesterone compared with placebo, reduced the risk of preterm birth <37 gestational weeks: 26.8% vs. 30.2% (Risk Ratio [RR] 0.82 [95% Confidence Interval [CI] 0.71 to 0.95]) (high certainty of evidence, 14 trials) thereby reducing neonatal mortality and respiratory distress syndrome. Cerclage probably reduced the risk of preterm birth <37 gestational weeks: 29.0% vs. 37.6% (RR 0.78 [95% CI 0.69 to 0.88]) (moderate certainty of evidence, four open trials). In addition, perinatal mortality may be reduced by cerclage. Pessary did not demonstrate any overall effect. ASA did not affect any outcome, but evidence was based on one underpowered study.Multifetal pregnancies: The effect of progesterone, cerclage, or pessary was minimal, if any. No study supported improved long-term outcome of the children.

Conclusion

Progesterone and probably also cerclage have a protective effect against preterm birth in asymptomatic women with a singleton pregnancy at risk of preterm birth. Further trials of ASA are needed. Prevention of preterm birth requires screening programs to identify women at risk of preterm birth.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021234946].

McDonald versus Shirodkar cerclage technique in the prevention of preterm birth: A systematic review and meta-analysis

BACKGROUND

Cervical cerclage has been used for decades to reduce preterm birth. The Shirodkar and McDonald cerclage are the most commonly used techniques with no current consensus on the preferred technique.

OBJECTIVE

To compare the efficacy of the Shirodkar and McDonald cerclage techniques in preventing preterm birth.

SEARCH STRATEGY

Studies were sourced from six electronic databases and reference lists.

SELECTION CRITERIA

Studies including women with a singleton pregnancy, requiring a cervical cerclage, using either the Shirodkar or McDonald technique that ran comparative analyses between the two techniques.

DATA COLLECTION AND ANALYSIS

The primary outcome was preterm birth before 37 weeks, with analyses at 28, 32, 34 and 35 weeks. Secondary data were also collected on neonatal, maternal and obstetric outcomes.

MAIN RESULTS

Seventeen papers were included: 16 were retrospective cohort studies and one was a randomised controlled trial. The Shirodkar technique was significantly less likely to result in preterm birth before 37 weeks than the McDonald technique (relative risk [RR] 0.91, 95% CI 0.85-0.98). This finding was supported by a statistically significant reduction in rates of preterm birth before 35, 34 and 32 weeks, PPROM, difference in cervical length, cerclage to delivery interval, and an increase in birthweight in the Shirodkar group. No difference was seen in preterm birth rates <28 weeks, neonatal mortality, chorioamnionitis, cervical laceration or caesarean section rates. The RR for preterm birth prior to 37 weeks was no longer significant when sensitivity analyses were performed removing studies with a serious risk of bias. However, similar analyses removing studies that utilised adjunctive progesterone strengthened the primary outcome (RR 0.83, 95% CI 0.74-0.93).

CONCLUSION

Shirodkar cerclage reduces the rate of preterm birth prior to 35, 34 and 32 weeks' gestation when compared with McDonald cerclage; however, the overall quality of the studies in this review is low. Further, large, well-designed randomised controlled trials are required to address this important question to optimise care for women who may benefit from cervical cerclage.

Midtrimester Cervical Length in Low-Risk Nulliparous Women for the Prediction of Spontaneous Preterm Birth: Should We Consider a New Definition of Short Cervix?

OBJECTIVE

The study aimed to estimate the predictive value of midtrimester cervical length (CL) and the optimal cut-off of CL that should be applied with asymptomatic nulliparous women for the prediction of spontaneous preterm birth (sPTB).

STUDY DESIGN

This is a prospective cohort study of asymptomatic nulliparous women with a singleton gestation. Participants underwent CL measurement by transvaginal ultrasound between 20 and 24 weeks of gestation. The participants and their health care providers remained blinded to the results of CL measurement. The primary outcomes were sPTB before 35 weeks and sPTB before 37 weeks. Receiver operating characteristics (ROC) curve analyses were performed. Analyses were repeated by using multiples of median (MoM) of CL adjusted for gestational age.

RESULTS

Of 796 participants, the mean midtrimester CL was 40 ± 6 mm with a 1st, 5th, and 10th percentile of 25, 29, and 32 mm, respectively. ROC curve analyses suggest that a cut-off of 30 mm was the optimal CL to predict sPTB before 35 weeks (area under the ROC curve [AUC]: 0.70, 95% confidence interval [CI]: 0.56-0.85) and before 37 weeks (AUC: 0.70, 95% CI: 0.59-0.80). Midtrimester CL <30 mm could detect 35% of all sPTB before 35 weeks at a false-positive rate of 5% (relative risk: 9.1, 95% CI: 3.5-23.5, p < 0.001). We observed similar results using a cut-off of CL <0.75 MoM adjusted for gestational age.

CONCLUSION

A midtrimester CL cut-off of 30 mm (instead of 25 mm), or CL less than 0.75 MoM, should be used to identify nulliparous women at high risk of sPTB.

KEY POINTS

· The optimal CL cut-off for the prediction of sPTB is 30 mm in nulliparous women.. · In nulliparous women, a midtrimester CL < 30 mm is highly associated with sPTB before 35 and 37 weeks.. · A midtrimester of CL <30 mm (5th percentile) should define a short cervix in asymptomatic nulliparous women..

Pre-Cerclage cervical length predicts long-term pregnancy sustenance: A case-control study

Background

This study aimed to assess a predictor of long-term pregnancy sustenance post cervical cerclage in women with or without a medical history of cervical insufficiency.

Materials and methods

We included pregnant women who underwent cerclage at 12–25 weeks gestation in four perinatal medical centers between January 2009 and December 2010. We classified the cerclage modality as ultrasound-indicated cervical cerclage if the pre-cerclage CL was <25 mm because the prophylactic and therapeutic cerclage definitions varied among institutions. The procedure was deemed successful if the pregnancy continued for more than 13 weeks post cerclage. We compared the outcomes of women who underwent successful and unsuccessful cerclage and investigated whether the pre-cerclage CL could predict pregnancy outcomes in women who underwent successful cerclage using receiver-operating characteristic curves.

Results

We screened 114 pregnant women; 91 met the inclusion criteria. Pre-cerclage CL was a moderately accurate predictor of long-term pregnancy sustenance in the successful group (optimal cut-off value: 17 mm; area under the curve: 0.76; P = 0.0016). Approximately 87% of patients with a pre-cerclage CL ≥ 17 mm sustained their pregnancies for more than 13 weeks post cerclage; however, 64% of patients with a pre-cerclage CL < 17 mm did not.

Conclusion

We speculate that the use of other treatment options in addition to cerclage in women with a pre-cerclage CL < 17 mm may result in a successful pregnancy.

•

Cervical cerclage encompasses many indications and specific techniques.

•

Pre-cerclage cervical length (CL) predicts long-term pregnancy sustenance.

•

87% women (pre-cerclage, CL ≥ 17 mm) sustained their pregnancy for >13 weeks.

•

64% women (pre-cerclage, CL < 17 mm) did not sustain their pregnancy for >13 weeks.

•

Cerclage can be considered in women with a pre-cerclage CL < 17 mm.

Cerclage versus vaginal progesterone in low-risk pregnant women with a short cervix

OBJECTIVE

To compare vaginal progesterone to cerclage in preventing preterm birth and adverse perinatal outcomes in women with a singleton gestation, incidentally found sonographic cervical length of <15 mm, and no history of preterm birth.

STUDY DESIGN

A retrospective cohort study was conducted on 68 women who delivered at the University of Kansas Health System with a singleton gestation found to have a cervical length <15 mm on transvaginal ultrasound and no history of preterm birth. Women treated with vaginal progesterone (n = 29) were compared to women who underwent cerclage placement (n = 39). The primary outcome was preterm birth at <34 weeks of gestation. Secondary outcomes include preterm birth at <37 and <28 weeks of gestation and neonatal morbidities.

RESULTS

Of the 268 patients who had a cervical length of <15 mm on transvaginal ultrasound, 68 participants met inclusion criteria and were included in the final analysis. Twenty-nine participants received vaginal progesterone and 39 participants received cervical cerclage. The average cervical length at initiation of therapy was greater in the progesterone cohort versus cerclage cohort, respectively (10.5 vs. 8.0 mm, p < .01). All other baseline characteristics were similar between groups, including no difference in average gestational age at initiation of therapy (21.6 vs. 21.5 weeks, p = .87). Average latency after therapy did not differ between groups (100 vs. 92.7 days p = .43). The incidence of preterm birth at <37 weeks (OR = 1.49, 95% CI = 0.57-3.93), <34 weeks (OR = 1.47, 95% CI = 0.52-4.18), and <28 weeks (OR = 1.90, 95% CI = 0.45-8.07), did not differ significantly between groups. Additionally, no difference in neonatal morbidity was detected.

CONCLUSION

At our institution, we found no difference between vaginal progesterone and cerclage in the average latency period or risk of preterm birth among women with an incidental short cervix of <15 mm and no history of preterm birth, despite the significantly shorter initial cervical length in the cerclage group. These findings suggest either vaginal progesterone or cerclage could be used to reduce the risk of preterm birth among this high-risk population.

Prognosis and Prognostic Factors of Patients with Emergent Cerclage: A Japanese Single-Center Study

Objectives

The aims of this study were to clarify the following: (1) how often does prolonged pregnancy ≥34 weeks occur in patients with emergent cerclage without progesterone and (2) the risk factors preventing such pregnancy continuation.

Materials and Methods

This retrospective observational study was performed using medical records of patients for whom emergent cerclage had been performed between April 2006 and December 2018 in our institute.

Results

Emergent cerclage was performed in 123 patients (median age: 34, interquartile range: 31–36). Primiparous patients numbered 44 (36%). A history of spontaneous preterm birth (SPTB) was present in 30 (24%). The median presurgical cervical length (CL) was 16 (8–21) mm at surgery. Of the 123, 20 (16%) were delivered at 33 + 6 weeks or less (<34 weeks). We conducted logistic regression analysis of the risk factors of SPTBs <34 weeks after cerclage. Three risk factors were identified that increased the risk of SPTB <34 weeks: presurgical CL 0 mm (odds ratio (OR): 5.30; 95% confidence interval (CI): 1.58–17.7), a history of SPTB (OR: 4.65; 95% CI: 1.38–15.7), and the presence of sludge (OR: 4.14; 95% CI: 1.20–14.3).

Conclusion

Three risk factors predicted SPTB <34 weeks after emergency cerclage without progesterone administration: unmeasurable CL (CL 0 mm), a history of SPTB, and the presence of sludge on ultrasound. SPTB <34 weeks occurred after emergency cerclage in 16% of patients, being comparable with the recent data with progesterone.

Evaluation of midtrimester cervical length thresholds for the prediction of spontaneous preterm birth

INTRODUCTION

To estimate the optimal midtrimester cervical length (CL) threshold for the prediction of spontaneous preterm birth (sPTB) in asymptomatic pregnant women.

MATERIAL AND METHODS

This is a prospective observational cohort study including asymptomatic women with singleton pregnancies who underwent CL measurement by transabdominal and/or transvaginal ultrasound between 19°^/7 and 21^6/7 weeks of gestation. All CL ≤30 mm from transabdominal ultrasound were confirmed by transvaginal ultrasound. Primary outcomes were sPTB <35 and <37 weeks.

RESULTS

Out of 3,449 participants, 28 (0.8%) had a sPTB before 35 weeks and 99 (2.9%) had a sPTB before 37 weeks. Receiver operating characteristics (ROC) curves suggest that a cut-off of 30 mm was the optimal CL to predict sPTB before 35 weeks (sensitivity: 43%; specificity: 97%) and sPTB before 37 weeks (sensitivity: 21%; specificity: 97%). While a CL <25 mm was an important risk factor for sPTB before 35 weeks (relative risk: 31; 95% confidence interval: 13-73), women with a CL between 25 and 30 mm were also at greater risk (relative risk: 12; 95% confidence interval: 4 - 35) compared to women with CL ≥30 mm.

DISCUSSION

A midtrimester CL <30 mm should be considered to identify women at high-risk of sPTB.

Incidences of complications associated with cervical cerclage by indication of the procedure

AIM

To investigate the incidence of complications associated with cervical cerclage by indication.

METHODS

This was a retrospective cohort study of women with singleton pregnancies who underwent cervical cerclage in a single perinatal center between 2008 and 2019. The participants were divided into three groups according to indication: history-indicated cerclage (HIC) group, ultrasound-indicated cerclage (UIC) group, and physical examination-indicated cerclage (PEIC) group. The incidences of perioperative complications within 2 weeks after the procedure, including intraoperative rupture of membranes, intraoperative bleeding, anesthesia complications, clinical chorioamnionitis, premature rupture of membranes (PROM), preterm delivery, and displacement of the suture, and those of peripartum complications, including difficult suture removal and cervical laceration, for each group were compared using Fisher's exact test or Pearson's chi-square test. Factors associated with severe adverse event, defined as PROM or delivery within 2 weeks after the procedure, were analyzed using multivariate logistic regression analysis.

RESULTS

A total of 279 women (HIC, 38; UIC, 96; PEIC, 145) were enrolled. The incidence of perioperative complications was different among the three groups (7.9%, 10.4%, and 27.6%, respectively; p < 0.01), whereas that of peripartum complications was similar (18.4%, 11.5%, and 12.4%, respectively; p = 0.54). Severe adverse events occurred only in PEIC group, with an incidence of 18.6%. The associated factor for severe adverse events in PEIC group was prolapsed membranes into the vagina.

CONCLUSIONS

Incidences of perioperative complications of cerclage differed among the indications. Women who underwent PEIC had higher risk of severe adverse events, especially when accompanied with prolapsed membranes into the vagina.

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.

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.

Cervical length distribution and other sonographic ancillary findings of singleton nulliparous patients at midgestation

BACKGROUND

Short cervix at midgestation, the presence of intraamniotic debris, and cervical funneling are risk factors for preterm birth; however, cervical length measurements and cutoffs are not well documented among pregnant patients of different gestational ages and self-reported races and ethnicities.

OBJECTIVE

This study aimed to describe the distribution of cervical length and frequency of funneling and debris at midgestation in nulliparous women by gestational age and race/ethnicity.

STUDY DESIGN

This secondary analysis of screening data from a multicenter treatment trial of singleton nulliparous patients with short cervix was conducted at 14 geographically distributed, university-affiliated medical centers in the United States. Singleton nulliparous patients with no known risk factors for preterm birth were screened for trial participation and asked to undergo a transvaginal ultrasound to measure cervical length by a certified sonographer. The distribution of cervical length and the frequency of funneling and debris were assessed for each gestational age week (16-22 weeks) and stratified by self-reported race and ethnicity, which for this study were categorized as White, Black, Hispanic, and other. Patients enrolled in the randomized trial were excluded from this analysis.

RESULTS

A total of 12,407 nulliparous patients were included in this analysis. The racial or ethnic distribution of the study participants was as follows: White, 41.6%; Black, 29.6%; Hispanic, 24.2%; and others, 4.6%. The 10th percentile cervical length for the entire cohort was 31.1 mm and, when stratified by race and ethnicity, 31.9 mm for White, 30.2 mm for Black, 31.4 mm for Hispanic, and 31.2 mm for patients of other race and ethnicity (P<.001). At each gestational age, the cervical length corresponding to the tenth percentile was shorter in Black patients. The 25 mm value commonly used to define a short cervix and thought to represent the 10th percentile ranged from 1.3% to 5.4% across gestational age weeks and 1.0% to 3.8% across race and ethnicity groups. Black patients had the highest rate of funneling (2.6%), whereas Hispanic and Black patients had higher rates of intraamniotic debris than White and other patients (P<.001).

CONCLUSION

Black patients had shorter cervical length and higher rates of debris and funneling than White patients. The racial and ethnic disparities in sonographic midtrimester cervical findings may provide insight into the racial disparity in preterm birth rates in the United States.

Cerclage in singleton gestations with an extremely short cervix (≤10 mm) and no history of spontaneous preterm birth

BACKGROUND

Data regarding the efficacy of a cervical cerclage for preterm birth prevention in patients with a short cervix and no history of spontaneous preterm birth are limited and inconclusive.

OBJECTIVE

This study aimed to determine whether cervical cerclage is associated with an increased time interval to delivery in asymptomatic patients with singleton pregnancies with an extremely short cervical length (≤10 mm) and no history of spontaneous preterm birth.

STUDY DESIGN

This was a multicenter retrospective cohort study of asymptomatic patients with singleton pregnancies with a cervical length of ≤10 mm between 16 and 23 weeks' gestation from January 2014 to December 2019. Patients with previous spontaneous preterm birth, symptoms of preterm labor, cervical dilation of >1 cm, pessary, major fetal structural malformations, or missing data were excluded from the study. The primary outcome of time interval from diagnosis to delivery was compared between those who had a cervical cerclage after diagnosis and those who did not. The secondary outcomes included gestational age at delivery and adverse neonatal outcomes. Moreover, a subgroup analysis of all outcomes in patients already being treated with vaginal progesterone in each group was performed. Statistical analysis included chi-square and Wilcoxon rank-sum tests and a multivariate Cox proportional hazard regression for time interval to delivery.

RESULTS

Of the 90 patients included in the study, 52 (57.8%) had cervical cerclage, of which 35 (67.3%) were already being treated with progesterone. Moreover, 38 patients (42.2%) did not have cervical cerclage, of which 21 (55.3%) were already being treated with progesterone. Patients in the cervical cerclage group had an earlier gestational age (21.0 vs 22.0 weeks' gestation; P≤.001) and shorter cervical length (5 vs 7 mm; P=.002) at the diagnosis of a short cervix (cervical length≤10 mm) than those who did not have a cerclage. Cervical cerclage was associated with a longer time interval to delivery (17.0 vs 15.0 weeks; P=.02) and lower hazard of earlier delivery after diagnosis (adjusted hazard ratio, 0.61; 95% confidence interval, 0.38-0.99; P=.04) than no cerclage, after accounting for gestational age and cervical length at diagnosis. In patients already treated with progesterone, cervical cerclage was also associated with a longer time interval to delivery (17.0 vs 13.1 weeks; P=.01) and a lower hazard of earlier delivery after diagnosis (adjusted hazard ratio, 0.49; 95% confidence interval, 0.27-0.87; P=.02) compared to those with no cerclage. Late preterm birth was less common in patients with a cervical cerclage compared with those with no cervical cerclage (11.5% vs 31.6%; P=.03).

CONCLUSION

Cervical cerclage should be considered in asymptomatic patients with an extremely short cervical length (≤10 mm) and no history of spontaneous preterm birth.

Translocation of vaginal microbiota is involved in impairment and protection of uterine health

The vaginal and uterine microbiota play important roles in the health of the female reproductive system. However, the interactions among the microbes in these two niches and their effects on uterine health remain unclear. Here we profile the vaginal and uterine microbial samples of 145 women, and combine with deep mining of public data and animal experiments to characterize the microbial translocation in the female reproductive tract and its role in modulating uterine health. Synchronous variation and increasing convergence of the uterine and vaginal microbiome with advancing age are shown. We also find that transplanting certain strains of vaginal bacteria into the vagina of rats induces or reduces endometritis-like symptoms, and verify the damaging or protective effects of certain vaginal bacteria on endometrium. This study clarifies the interdependent relationship of vaginal bacterial translocation with uterine microecology and endometrial health, which will undoubtedly increase our understanding of female reproductive health.

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.

Guideline No. 401: Sonographic Cervical Length in Singleton Pregnancies: Techniques and Clinical Applications

OBJECTIVES

• To assess the association between sonography-derived cervical length measurement and preterm birth. • To describe the various techniques to measure cervical length using sonography. • To review the natural history of the short cervix. • To review the clinical uses, predictive ability, and utility of sonography-measured short cervix.

OUTCOMES

Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions.

INTENDED USERS

Clinicians involved in the obstetrical management or cervical imaging of patients at increased risk of a short cervix.

TARGET POPULATION

Women at increased risk of a short cervix or at risk of preterm birth.

EVIDENCE

Literature published up to June 2019 was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, cervical insufficiency, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence and this guideline were reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made and graded according to the rankings of the Canadian Task Force on Preventive Health Care (Online Appendix Table A1).

BENEFITS, HARMS, COSTS

Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the sonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth. SUMMARY STATEMENTS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES): RECOMMENDATIONS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES).

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.

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.

Emergency Cervical Cerclage

Despite the progress of medicine in the last decades, recurrent pregnancy loss, premature birth, and related complications are still a vast problem. The reasons for recurrent pregnancy loss and preterm delivery are diverse and multifactorial. One of the main reasons for these complications is cervical insufficiency, which means that the cervix is weak and unable to remain closed until the date of delivery. It manifests as painless softening and shortening of the cervix without contractions. The aim of the study was to review the available literature on rescue sutures, which are an emergency treatment in pregnancies with premature cervical dilatation and protrusion of the fetal membranes in the second trimester of pregnancy. This review confirms that emergency cerclage reduces the rate of preterm birth in patients with advanced cervical insufficiency. This procedure prolongs gestational age and improves the chances of survival of the newborn without increasing the risk of chorioamnionitis and preterm premature rupture of membranes.

Current Approaches to Risk Assessment and Prevention of Preterm Birth-A Continuing Public Health Crisis

Background: Preterm birth remains a major cause of neonatal morbidity and mortality. Several potential pathways and pathophysiologic processes can lead to preterm birth, complicating efforts to screen for the risk of preterm birth and making implementation of prevention strategies difficult.

Methods: Based on a review of the literature, this article addresses screening strategies for preterm birth risk stratification and interventions for preterm birth prevention.

Results: In women with a history of a prior spontaneous preterm birth, cervical cerclage placement in the setting of short cervix reduces the rate of recurrent spontaneous preterm birth. Weekly injections of 17-hydroxyprogesterone caproate (17-P) have been used as standard treatment for the prevention of recurrent preterm birth since 2011. However, results of a replication study of 17-P published in 2020 have raised questions regarding the effectiveness of this drug, and it is under review by the US Food and Drug Administration. Among women with no history of preterm birth, cervical length appears to be the best predictor of risk for preterm birth in asymptomatic women. In women with a cervical length <25 mm, vaginal progesterone has been demonstrated to reduce the risk of preterm birth.

Conclusion: Strategies including cervical length screening, vaginal progesterone administration, cervical cerclage placement, and, potentially, 17-P administration may help reduce rates of preterm birth when used in the appropriate patient populations. Development of protocols for patient evaluation and risk stratification will help identify patients at highest risk for preterm birth and allow use of the best available therapeutic interventions.

Cervical cerclage application algorithm in continued cervical shortening cases despite vaginal progesterone

OBJECTIVE

The aim of this study is evaluation of pregnancy outcomes of the asymptomatic cases with vaginal progesterone treatment for the 20-30 mm cervical length detected in the transvaginal ultrasonography for fetal abnormality screening and cervical cerclage after cervical length detected <20 mm in weekly cervical length measures; and present the treatment algorithm of progesterone treatment combined with cervical cerclage application.

METHODS

Patients who have the inclusion criteria and cervical length more than 30 mm were categorized as group 1(n = 1948). Group 2 were included patients with cervical length shorter than 30 mm (n = 95). All patients of group 2 started to use vaginal natural progesterone 400 mg/day(n = 87). Pregnancies which progressed with cervical length above 20 mm were continued vaginal progesterone until 34. Gestational week and they were named as group 2A (n = 78). Cervical cerclage were applied to patients with cervical length below than 20 mm measured via transvaginal ultrasonography and they were categorized as group 2B (n = 9).

RESULTS

Excluding 8 cases (8.42 %) which cervical cerclage were applied, 87 patients were administered vaginal progesterone and in 9 cases (10.34 %) cervical shortening were continued despite progesterone treatment. Four out of these nine cases (44.44 %) had cervical cerclage and their deliveries were delayed after 34 th gestational week. Vaginal progesterone treatment prevented cervical shortening in 89.66 % of patients who had cervical length between 20-30 mm and out of these patients.

CONCLUSION

Cervical cerclage application algorithm in continued cervical shortening cases despite vaginal progesterone is beneficial to delay the delivery after 34 th gestational week and related to low complication rate.

Cervical insufficiency: a noteworthy disease with controversies

Cervical insufficiency (CI) is a mainly disease leading to recurrent abortions and preterm birth which may present in about 1% of obstetric populations. Recurrent pregnancy losses caused by CI incur serious economic burdens on society as well as huge psychological burdens to family members. However, many patients even clinicians in some areas of the world still remain confused about this disease. At the same time, the etiology of CI is still uncertain and it is still a controversial disease in diagnosis and treatment. This article summarizes the potential risk factors associated with CI, which could be worthy of attention and helpful for future research. It also reviews the methods for diagnosis and treatment of CI to better understand this noteworthy disease, as well as presents the related consensus and controversies according to the newly updated guidelines, which has practical significance for conducting more in-depth investigations in the future.

Spontaneous preterm birth and cervical length in a pregnant Asian population

Objective

Preterm birth (birth before 37 weeks of completed gestation) is the leading cause of neonatal death, and has an incidence of 5–13% which is believed to be on the rise. The objective of this study was to determine the rate of spontaneous preterm birth and investigate the relationship between preterm birth and cervical length in a pregnant Asian population.

Materials and methods

A prospective observational study between September 2010 and November 2013 was performed at KK Women’s and Children’s Hospital, Singapore. 1013 women with single viable pregnancies were recruited at less than 14 weeks of gestation between September 2010 and November 2013, excluding those with multiple gestation, pre-existing autoimmune or renal disease or those with current pregnancies complicated by aneuploidy or fetal anomalies. Participant characteristics were obtained from an interviewer-administered questionnaire at the first recruitment visit. Cervical length was measured using ultrasound at each of the 4 antenatal visits (Visit 1: < 14 weeks, Visit 2: 18–22 weeks, Visit 3: 28–32 weeks and Visit 4: > 34 weeks) using the Fetal Medicine Foundation protocol. Data on pregnancy outcomes were obtained from obstetric case notes and records. The main outcome measure examined in this study was that of spontaneous preterm birth and its relationship to cervical length.

Results

There was a significantly shorter cervical length both in the 2nd trimester (18 to 22 weeks) and the 3rd trimester (28 to 32 weeks) in the preterm birth group compared to the term birth group (p = 0.028 and p < 0.001 respectively). In the first trimester (11 to 14 weeks), there was no statistically significant difference in cervical length between the two groups (p = 0.425). ROC curve analysis for cervical length in the preterm birth group for 18 to 22 weeks and 28 to 32 weeks showed an AUC of 0.605 and 0.725 respectively. At 28 to 32 weeks of gestation, a cut-off level at 2.49 cm has a sensitivity of 54.8%, specificity of 82.5%, negative predictive value of 97.9% and positive predictive value of 11.1%.

Conclusion

There is a significantly shorter cervical length in the 2nd and 3rd trimester in the preterm birth group. Cervical length is a moderate predictor of preterm birth with good negative predictive value and a relatively good specificity. Ultrasound cervical length screening for pregnant Asian women between 18 and 22 weeks of gestation with a cutoff of ≥ 2.48cm can help to identify a group of women who are at risk for preterm birth.

The role of noninvasive diagnostic imaging in monitoring pregnancy and detecting patients at risk for preterm birth: a review of quantitative approaches

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality worldwide. The ability to predict patients at risk for preterm birth remains a major health challenge. The currently available clinical diagnostics such as cervical length and fetal fibronectin may detect only up to 30% of patients who eventually experience a spontaneous preterm birth. This paper reviews ongoing efforts to improve the ability to conduct a risk assessment for preterm birth. In particular, this work focuses on quantitative methods of imaging using ultrasound-based techniques, magnetic resonance imaging, and optical imaging modalities. While ultrasound imaging is the major modality for preterm birth risk assessment, a summary of efforts to adopt other imaging modalities is also discussed to identify the technical and diagnostic limits associated with adopting them in clinical settings. We conclude the review by proposing a new approach using combined photoacoustic, ultrasound, and elastography as a potential means to better assess cervical tissue remodeling, and thus improve the detection of patients at-risk of PTB.

The risk of spontaneous preterm birth in asymptomatic women with a short cervix (≤25 mm) at 23-28 weeks' gestation

BACKGROUND

Asymptomatic short cervical length is an independent risk factor for spontaneous preterm birth. However, most studies have focused on the associated risk of a short cervical length when encountered between 16 and 23 weeks' gestation. The relationship between cervical length and risk of spontaneous preterm birth after 23 weeks is not well known.

OBJECTIVE

To evaluate the risk of spontaneous preterm birth in asymptomatic women with a short cervix (≤25 mm) at 23-28 weeks' gestation.

MATERIALS AND METHODS

A retrospective cohort study of women with asymptomatic short cervix (cervical length ≤25 mm) at extreme prematurity, defined as 23-28 weeks' gestation, was performed at a single center from January 2015 to March 2018. Women with symptoms of preterm labor, multiple gestations, fetal or uterine anomalies, cervical cerclage, or those with incomplete data were excluded from the study. Demographic information as well as data on risk factors for spontaneous preterm birth were collected. Patients were divided into 4 groups based on the cervical length measurement (≤10 mm, 11-15 mm, 16-20 mm, and 21-25 mm). The primary outcome was time interval from enrollment to delivery. Secondary outcomes included delivery within 1 and 2 weeks of enrollment, gestational age at delivery, and delivery prior to 32, 34, and 37 weeks, respectively. Continuous variables were compared using Kruskal-Wallis test, whereas categorical variables were compared using the χ² or Fisher exact test as appropriate. The Wilcoxon test for difference in survival time was used to compare gestational age at delivery among the 4 cervical length groups, with data stratified based on gestational age at enrollment.

RESULTS

Of the 126 pregnancies that met inclusion criteria, 22 (17.4%) had a cervical length of ≤10 mm, 23 (18.3%) had a cervical length of 11-15 mm, 37 (29.4%) had a cervical length of 16-20 mm, and 44 (34.9%) had a cervical length of 21-25 mm. Baseline characteristics were similar among all 4 groups. The shorter cervical length group was associated with a shorter time interval from enrollment to delivery (cervical length ≤10 mm, 10 weeks; cervical length 11-15 mm, 12.7 weeks; cervical length of 16-20 mm, 13 weeks; cervical length of 21-25 mm, 13.2 weeks; P = .006). Regardless of the cervical length measurement, delivery within 2 weeks was extremely uncommon (1 patient; 0.8%). The prevalence of spontaneous preterm birth at <32 weeks or <34 weeks was higher in women with a cervical length of ≤10 mm compared to those with a longer cervical length (P < .001).

CONCLUSIONS

The risk of spontaneous preterm birth in asymptomatic women with a sonographic short cervix increases as cervical length decreases. The risk is substantially higher in women with a cervical length of ≤10 mm. Women with a cervical length of ≤10 mm also had the shortest time interval to delivery. Nevertheless, delivery within 1 or 2 weeks is highly unlikely, regardless of the cervical length at the time of enrollment. Therefore, based on our data, we suggest that management decisions such as timing of administration of antenatal corticosteroids in asymptomatic patients with a cervical length of ≤25 mm at 23-28 weeks' gestation may be delayed until additional indications are present.

The effect of postoperative vaginal progesterone in ultrasound-indicated cerclage to prevent preterm birth

OBJECTIVES

To compare pregnancy outcomes according to the use of postoperative vaginal progesterone in patients who underwent ultrasound-indicated cerclage.

METHODS

This was a retrospective cohort study of 86 consecutive asymptomatic singleton pregnancies who had undergone cerclage because of incidentally found short cervical length under 20 mm through transvaginal ultrasound between 16°^/7 and 24^6/7 weeks' gestational age. Outcomes were compared according to the use of vaginal progesterone after cerclage. Primary outcome measure was preterm delivery < 34 weeks of gestation.

RESULTS

(1) The frequency of preterm delivery < 34 weeks of gestation was significantly lower in patients with postoperative vaginal progesterone than those without (2.2 versus 18.4%, p = .021); (2) the median gestational age at delivery in the postoperative vaginal progesterone group was significantly longer than the control group (38.3 weeks (interquartile range, 37.5-39.1 weeks) versus 37.3 weeks (interquartile range 33.9-38.6 weeks), p = .020); (3) Multivariable logistic regression analysis demonstrated the use of vaginal progesterone after cerclage was found to be independently associated with decrease in preterm delivery before 34 weeks (Odds ratio 0.10; 95% confidence interval, 0.01-0.93) and 37 weeks (Odds ratio 0.24; 95% confidence interval, 0.07-0.85).

CONCLUSIONS

The use of vaginal progesterone was associated with lower rates of preterm birth before 34 and 37 weeks of gestation in women who underwent ultrasound-indicated cerclage placement.

Patients with acute cervical insufficiency without intra-amniotic infection/inflammation treated with cerclage have a good prognosis

Background The frequency of intra-amniotic infection/inflammation (IAI/I) in patients with midtrimester cervical insufficiency is up to 50%. Our purpose was to determine the perinatal outcomes of cervical cerclage in patients with acute cervical insufficiency with bulging membranes, and to compare the admission-to-delivery interval and pregnancy outcomes according to the results of amniotic fluid (AF) analysis and cerclage placement. Methods This was a retrospective cohort study including singleton pregnancies with cervical insufficiency between 15 and 26.9 weeks in two tertiary health centers. IAI/I was defined when at least one of the following criteria was present in AF: (a) a white blood cell (WBC) count >50 cells/mm3; (b) glucose concentration <14 mg/dL; and/or (c) a Gram stain positive for bacteria. Three different groups were compared: (1) absence of IAI/I with placement of a cerclage; (2) amniocentesis not performed with placement of a cerclage; and (3) IAI/I with or without a cerclage. Results Seventy patients underwent an amniocentesis to rule out IAI/I. The prevalence of IAI/I was 19%. Forty-seven patients underwent a cerclage. Patients with a cerclage had a longer median admission-to-delivery interval (33 vs. 2 days; P < 0.001) and delivered at a higher median gestational age (27.4 vs. 22.6 weeks; P = 0.001) than those without a cerclage. The neonatal survival rate in the cerclage group was 62% vs. 23% in those without a cerclage (P = 0.01). Patients without IAI/I who underwent a cerclage had a longer median admission-to-delivery interval (43 vs. 1 day; P < 0.001), delivered at a higher median gestational age (28 vs. 22.1 weeks; P = 0.001) and had a higher neonatal survival rate (67% vs. 8%; P < 0.001) than those with IAI/I. Conclusion The pregnancy outcomes of patients with midtrimester cervical insufficiency and bulging membranes are poor as they have a high prevalence of IAI/I. Therefore, a pre-operative amniocentesis is key to identify the best candidates for the subsequent placement of a cerclage.

Cervical modifications after pessary placement in singleton pregnancies with maternal short cervical length: 2D and 3D ultrasound evaluation

INTRODUCTION

The use of a pessary proved to prevent preterm birth in asymptomatic women with mid-trimester short cervical length (CL); however, the precise mechanisms by which the pessary confers its benefit remain unclear. The aim of this study was to evaluate multiple cervical characteristics assessed by 2-dimensional and 3-dimensional ultrasound before and after placement of a cervical pessary to ascertain its mechanism of action.

MATERIAL AND METHODS

In this prospective cohort study, we assessed the cervical characteristics in singleton pregnancies with maternal short CL and compared them with matched reference women with normal CL. The variables evaluated were: CL, uterocervical angles, cervical consistency indices (cervical consistency index and CL consistency index), cervical volume and vascular indices. All variables were re-assessed immediately after pessary placement and 4-6 weeks later in all participants. Mann-Whitney U test was used to assess differences between groups and paired samples t test for comparisons in two different examinations in the same women. The aim of this study was to evaluate multiple cervical ultrasound variables before and after the placement of a cervical pessary and compare the evolution of these variables with a reference group with normal CL to better understand the device's mechanism of action.

RESULTS

Thirty-three women with short CL and 24 reference women with normal CL were enrolled. At the time of enrollment, gestational age and maternal baseline characteristics did not differ between groups. Immediately after pessary placement, CL increased, uterocervical angles were narrower and cervical consistency increased significantly. When the magnitude of change in cervical variables was compared over time between the reference group and the study group, median CL had increased in the study group (1.47 mm) but it had shortened in the reference group (-2.56 mm). These inverse trends were statistically significant (P = 0.006).

CONCLUSIONS

Cervical pessary reduces both uterocervical angles and corrects cervical angulation by pushing the cervix up toward the uterus. Maintaining the cervix aligned to the uterine axis leads to reduced cervical tissue stretch, so avoiding further cervical shortening. All these changes were present after pessary placement; however, the clinical implications of these findings remain unknown.

Primary, secondary, and tertiary preventions of preterm birth with cervical cerclage

OBJECTIVE

To evaluate the efficacy of cerclage in preventing preterm birth according to indication.

STUDY DESIGN

Retrospective analysis of all women who underwent cerclage to prevent preterm birth in a university-affiliated medical-center (2007-2017). Multiple gestations were excluded. Cohort was divided to three subgroups according to cerclage indication: group A-primary prevention cerclage, performed during the first trimester, based on a history of cervical insufficiency; group B-secondary prevention cerclage, performed after sonographic visualization of asymptomatic cervical length shortening and previous preterm birth; and group C-tertiary prevention cerclage, performed at mid-trimester in women presenting with asymptomatic cervical dilatation. Primary outcome was gestational age at delivery. Secondary outcomes were maternal and neonatal complications.

RESULTS

During the study period 273 women underwent cervical cerclage: group A-215 (79%), group B-25 (9%), and group C-33 (12%). Patients in group C had significantly lower gravidity and parity. Gestational age at cerclage was highest in group C and lowest in group A (22 vs. 13 weeks p < 0.001). Median gestational age at delivery was 37 + 3 weeks in groups A and B and 34 + 3 in group C. This difference persisted after controlling for potential confounders (p  < 0.0001). Preterm birth prior to 34 weeks of gestation were 10.7% in group A, 16% in group B, and 33.33% in group C (p = 0.0021). Neonatal complications including: respiratory distress syndrome, intraventricular hemorrhage, and necrotizing enterocolitis, were clmore prevalent in group C.

CONCLUSION

Cerclage was shown to be an acceptable measure in cases of an anticipated increased risk of preterm birth with a low rate of procedure associated complications. However, the number-needed-to-treat cannot be determined from our data, because a control group was lacking.

Vaginal progesterone, oral progesterone, 17-OHPC, cerclage, and pessary for preventing preterm birth in at-risk singleton pregnancies: an updated systematic review and network meta-analysis

BACKGROUND

Recent progesterone trials call for an update of previous syntheses of interventions to prevent preterm birth.

OBJECTIVES

To compare the relative effects of different types and routes of administration of progesterone, cerclage, and pessary at preventing preterm birth in at-risk women overall and in specific populations.

SEARCH STRATEGY

We searched Medline, EMBASE, CINAHL, Cochrane CENTRAL, and Web of Science up to 1 January 2018.

SELECTION CRITERIA

We included randomised trials of progesterone, cerclage or pessary for preventing preterm birth in at-risk singleton pregnancies.

DATA COLLECTION AND ANALYSIS

We used a piloted data extraction form and performed Bayesian random-effects network meta-analyses with 95% credibility intervals (CrI), as well as pairwise meta-analyses, rating the quality of the evidence using GRADE.

MAIN RESULTS

We included 40 trials (11 311 women). In at-risk women overall, vaginal progesterone reduced preterm birth <34 (OR 0.43, 95% CrI 0.20-0.81) and <37 weeks (OR 0.51, 95% CrI 0.34-0.74), and neonatal death (OR 0.41, 95% CrI 0.20-0.83). In women with a previous preterm birth, vaginal progesterone reduced preterm birth <34 (OR 0.29, 95% CI 0.12-0.68) and <37 weeks (OR 0.43, 95% CrI 0.23-0.74), and 17α-hydroxyprogesterone caproate reduced preterm birth <37 weeks (OR 0.53, 95% CrI 0.27-0.95) and neonatal death (OR 0.39, 95% CI 0.16-0.95). In women with a short cervix (≤25 mm), vaginal progesterone reduced preterm birth <34 weeks (OR 0.45, 95% CI 0.24-0.84).

CONCLUSIONS

Vaginal progesterone was the only intervention with consistent effectiveness for preventing preterm birth in singleton at-risk pregnancies overall and in those with a previous preterm birth.

TWEETABLE ABSTRACT

In updated NMA, vaginal progesterone consistently reduced PTB in overall at-risk pregnancies and in women with previous PTB.

Preeclampsia outcomes at delivery and race

Objective: The objective of this study was to assess how race is associated with adverse maternal outcomes in the setting of preeclampsia.Study design: This retrospective cohort study utilized the National (Nationwide) Inpatient Sample (NIS) from the Agency for Health care Research and Quality for the years 2012-2014. Women aged 15-54 with a diagnosis of preeclampsia were included. Race and ethnicity were categorized as non-Hispanic white, non-Hispanic black, Hispanic, Asian or Pacific Islander, Native American, other, and unknown. The overall risk for severe morbidity based on Centers for Disease Control and Prevention criteria was analyzed along with the risk for specific outcomes such as stroke, acute heart failure or pulmonary edema, eclampsia, and acute renal failure. The risk for severe morbidity was stratified by comorbid risk and compared by race. Log-linear regression models were created to assess risk for severe morbidity with risk ratios and associated 95% confidence intervals as measures of effect.Results: A total of 101,741 women with preeclampsia from 2012 to 2014 were included in this analysis. The risk for severe morbidity was significantly higher among non-Hispanic black women (9.8%) than non-Hispanic white, Hispanic, and all other women, respectively (6.1, 7.7, and 7.5%, respectively, p < .01). For non-Hispanic black compared to non-Hispanic white, Hispanic, and all other women, risk was higher for stroke (17.1 versus 6.5, 12.7, and 9.3 per 10,000 deliveries, respectively, p < .01) and pulmonary edema or heart failure (56.2 versus 32.7, 30.2, and 38.4 per 10,000 deliveries, respectively, p < .01). Non-Hispanic black women were also more likely than non-Hispanic white women to experience renal failure (136.4 versus 60.4 per 10,000 deliveries, p < .01). Adjusting for comorbidity, black women remained at higher risk for severe morbidity (p < .01). The risk for death was higher for black compared to non-black women (121.8 per 100,000 deliveries, 95% CI 69.7-212.9 versus 24.1 per 100,000 deliveries, 95% CI 14.6-39.8, respectively, p < .01)Conclusion: Black women were at higher risk for severe morbidity and mortality associated with preeclampsia.

The first-trimester of pregnancy - A window of opportunity for prediction and prevention of pregnancy complications and future life

The International Federation of Gynecology and Obstetrics (FIGO) has identified non communicable maternal diseases (NCDs) as a new focus area. NCDs and exposures as related to pregnancy complications and later impairment of maternal and offspring health will form the basis for action in the forthcoming years. This paper summarizes recent advances, centered on the use of first-trimester testing, as a window of opportunity to predict and prevent many pregnancy complications; and for potential future prevention of NCDs in mother and offspring. Recent results from a large-scale randomized control trial have provided definitive proof that effective screening for preterm preeclampsia (preterm-PE), requiring delivery before 37 weeks' gestation, can be achieved with a combined test of maternal factors and biomarkers at 11-13 weeks and that aspirin, given to high-risk women, is effective in reducing the risk of preterm-PE and the length of stay in neonatal intensive care unit. This is the first successful example to illustrate that pregnancy complications is predictable and preventable in early pregnancy. Similar prediction and prevention strategies are being developed for hyperglycemia in pregnancy and preterm birth, with the intention for longer lasting interventions leading to significant downstream impact in improving long-term health in both mothers and babies.

Cervical cerclage for singleton pregnant patients on vaginal progesterone with progressive cervical shortening

BACKGROUND

Premature cervical ripening plays a significant role in spontaneous preterm birth. Vaginal progesterone is the recommended treatment in singleton pregnancy with incidental short cervix. There is lack of evidence on whether it is beneficial to reinforce the cervix with cerclage when the cervical length becomes progressively shortened <10 mm while on vaginal progesterone.

OBJECTIVE

Our aims are to determine whether cerclage with vaginal progesterone will: (1) reduce the overall spontaneous preterm birth rate, (2) prolong pregnancy latency, and (3) improve neonatal outcomes compared to vaginal progesterone alone.

STUDY DESIGN

This was a retrospective cohort study at the University of Illinois at Chicago of all women with singleton pregnancy on vaginal progesterone for incidental short cervix, cervical length <20 mm. Only those with progressive cervical length shortening <10 mm who delivered at the University of Illinois at Chicago from January 2013 through December 2016 were included. The decision to perform cerclage was based on individual physician preference. Demographic data; information on serial cervical length status; medical, obstetric, and social history; cerclage vs no cerclage; and neonatal outcomes were compared.

RESULTS

A total of 310 women with incidental short cervix on vaginal progesterone were identified, and of these, 75 had progressive shortening cervical length <10 mm and met inclusion criteria. Among the women with extremely shortened cervical length <10 mm, 36 women (48%) had cervical cerclage plus vaginal progesterone, and 39 women (52%) continued on vaginal progesterone alone. The baseline characteristics, mean cervical length (5.06 vs 5.52 mm), and mean gestational age at diagnosis of extreme short cervix (21.5 vs 21.3 weeks) were similar between women who received cerclage vs those who did not, respectively. The mean gestational age at delivery was significantly greater for those with cerclage (34 weeks and 3 days vs 27 weeks and 2 days; P < .001). The rate of spontaneous preterm birth at <37, 35, 32, 28, and 24 weeks were significantly lower in the cerclage group: 44.1% vs 84.2%, 38.2% vs 81.6%, 23.5% vs 78.9%, 14.7% vs 63.2%, and 11.8% vs 39.5%, respectively. The rate of spontaneous preterm birth <37 weeks remained significant after controlling for confounders (relative risk, 0.11; 95% confidence interval, 0.03-0.41; P < .001). The average pregnancy latency was 14 weeks in the cerclage combined with vaginal progesterone group compared to vaginal progesterone alone group. Neonatal intensive care unit admission and development of respiratory distress syndrome were significantly lower in the cerclage group compared to vaginal progesterone alone group: 13 (36.1%) vs 23 (65.7%) (relative risk, 0.55; 95% confidence interval, 0.34-0.90; P = .018) and 8 (22.2%) vs 17 (43.6%) (relative risk, 0.59; 95% confidence interval, 0.29-0.90; P = .027), respectively. Neonates of women with cerclage were also significantly less likely to develop necrotizing enterocolitis or experience neonatal death.

CONCLUSION

Our study showed that cerclage plus vaginal progesterone in women with extremely shortened cervix significantly decreased overall spontaneous preterm birth rates, prolonged pregnancy latency by 2-fold, and decreased the overall neonatal morbidity and mortality.