Cervical cerclage for short cervix at 24 to 26 weeks of gestation: systematic review and meta-analysis of randomized controlled trials using individual patient-level data.

OBJECTIVE: This study aimed to determine whether cervical cerclage for a transvaginal ultrasound-detected short cervical length after 24 weeks of gestation in singleton pregnancies reduces the risk for preterm birth. DATA SOURCES: Ovid MEDLINE, Scopus, and the Cochrane Central Register of Controlled Trials were searched using the following terms: "cerclage, cervical," "uterine cervical incompetence," "obstetrical surgical procedures," "cervix uteri," "randomized controlled trial," and "controlled clinical trial." STUDY ELIGIBILITY CRITERIA: All randomized controlled trials comparing cerclage placement with no cerclage in singleton gestations with a transvaginal ultrasound-detected short cervical length ≤25 mm between 24+0/7 and 29+6/7 weeks of gestation were eligible for inclusion. METHODS: Individual patient-level data from each trial were collected. If an eligible trial included patients with both multiple and singleton gestations with a short cervical length detected either before or after 24+0/7 weeks of gestation, only singletons who presented at or after 24+0/7 weeks were included. The primary outcome was preterm birth <37 weeks' gestation. Secondary outcomes included preterm birth <34, <32, and <28 weeks' gestation, gestational age at delivery, latency, preterm prelabor rupture of membranes, chorioamnionitis, and adverse neonatal outcomes. Individual patient-level data from each trial were analyzed using a 2-stage approach. Pooled relative risks or mean differences with 95% confidence intervals were calculated as appropriate. RESULTS: Data from the 4 eligible randomized controlled trials were included. A total of 131 singletons presented at 24+0/7 to 26+6/7 weeks of gestation and were further analyzed; there were no data on patients with a cerclage at 27+0/7 weeks' gestation or later. Of those included, 66 (50.4%) were in the cerclage group and 65 (49.6%) were in the no cerclage group. The rate of preterm birth <37 weeks' gestation was similar between patients who were randomized to the cerclage group and those who were randomized to the no cerclage group (27.3% vs 38.5%; relative risk, 0.78; 95% confidence interval, 0.37-1.28). Secondary outcomes including preterm birth <34, <32, and <28 weeks' gestation, gestational age at delivery, time interval from randomization to delivery, preterm prelabor rupture of membranes, and adverse neonatal outcomes such as low birthweight, very low birthweight, and perinatal death were similar between the 2 groups. Planned subgroup analyses revealed no statistically significant differences in the rate of preterm birth <37 weeks' gestation between the 2 groups when compared based on cervical length measurement (≤15 mm or ≤10 mm), gestational age at randomization (24+0/7 to 24+6/7 weeks or 25+0/7 to 26+6/7 weeks), or history of preterm birth. CONCLUSION: Cervical cerclage did not reduce or increase the rate of preterm birth among singleton pregnancies with a short cervical length detected after 24 weeks of gestation. Because there was a 22% nonsignificant decrease in preterm birth associated with cerclage, which is a similar amount of risk reduction often associated with ultrasound-indicated cerclage before 24 weeks' gestation, further randomized controlled trials in this patient population are warranted.

The Short Cervix: A Critical Analysis of Diagnosis and Treatment.

A short cervix in the second trimester is a significant risk factor for spontaneous preterm birth, preterm prelabor rupture of membranes, and subsequent adverse perinatal outcome. The pathophysiology is complex and multifactorial with inflammatory and/or infectious processes often involved. Biomarkers have been developed in an effort to predict preterm birth with varying degrees of success. The treatment options of cerclage, progesterone, pessary, and combination therapy are reviewed. Evidence-based protocols are summarized for singleton and multiple gestation.

History- or ultrasound-based cerclage placement and adverse perinatal outcomes.

OBJECTIVE: To determine whether cerclage based on serial transvaginal ultrasound (STVUS) vs. cerclage based on obstetric history (prior multiple midgestation losses) is superior for treatment of cervical insufficiency. STUDY DESIGN: This retrospective study evaluated all history-based or ultrasound-based cerclages in singleton pregnancies over a 5-year period at the University of Mississippi Medical Center. Demographic statistics, interval from cerclage placement to delivery, and gestational age at delivery were recorded, as were neonatal factors such as birthweight, morbidity, and mortality. RESULTS: No significant difference was found in regard to gestational age at delivery between the history-based cerclage and the ultrasound-based groups. The number of patients delivered before 24 weeks or after 34 weeks was similar. Birth weights, Apgar scores, and the number with growth restriction were similar between the two groups, as were perinatal loss and significant morbidity. In the ultrasound-based cerclage group, 52.1% did not require cerclage placement despite a history consistent with cervical insufficiency. CONCLUSION: There were no statistical differences between history-based and ultrasound-based cerclage in regard to obstetric or neonatal outcome. Using STVUS instead of cerclage procedures based on obstetric history, unnecessary procedures can be avoided in more than half the patients.

Cerclage for short cervix on ultrasonography in women with singleton gestations and previous preterm birth: a meta-analysis.

OBJECTIVE: To estimate if cerclage prevents preterm birth and perinatal mortality and morbidity in women with previous preterm birth, singleton gestation, and short cervical length in a meta-analysis of randomized trials. DATA SOURCES: MEDLINE, PUBMED, EMBASE, and the Cochrane Library were searched using the terms "cerclage," "short cervix," "ultrasound," and "randomized trial." METHODS OF STUDY SELECTION: We included randomized trials of cerclage in women with short cervical length on transvaginal ultrasonography, limiting the analysis to women with previous spontaneous preterm birth and singleton gestation. TABULATION, INTEGRATION, AND RESULTS: Patient-level data abstraction and analysis were accomplished by two independent investigators. Five trials met inclusion criteria. In women with a singleton gestation, previous spontaneous preterm birth, and cervical length less than 25 mm before 24 weeks of gestation, preterm birth before 35 weeks of gestation was 28.4% (71/250) in the cerclage compared with 41.3% (105/254) in the no cerclage groups (relative risk 0.70, 95% confidence interval 0.55­ 0.89). Cerclage also significantly reduced preterm birth before 37, 32, 28, and 24 weeks of gestation. Composite perinatal mortality and morbidity were significantly reduced (15.6% in cerclage compared with 24.8% in no cerclage groups; relative risk 0.64, 95% confidence interval 0.45­ 0.91). CONCLUSION: In women with previous spontaneous preterm birth, singleton gestation, and cervical length less than 25 mm, cerclage significantly prevents preterm birth and composite perinatal mortality and morbidity.

Controlled fine needle biopsy of the uterine cervix during pregnancy.

OBJECTIVE: Cervical sampling could furnish tissue-based information regarding premature cervical ripening and effacement. This report assesses the effect of cervical fine needle biopsy (FNB) in the evaluation of cervical shortening. METHODS: Retrospective cohort study evaluating adverse events during the first week following FNB in women with short cervix. Patients with a cervical length(CL) ≤25 mm had a cervical FNB between 16 and 24 weeks. The risk of FNB was compared to a control group that was similarly evaluated but did not undergo FNB. RESULTS: One hundred and thirty-two FNBs were performed in 94 participants. The mean gestational age and CL at enrollment were 20.4 ± 2.3 weeks and 15.7 ± 0.6 mm. Within 7 days of FNB, there were 3 adverse events (2.3%) in the study group compared to 5 in the control group (2.1%). CONCLUSIONS: FNB of the cervix in high risk gravidae is feasible in clinical situations. It did not increase the risk of adverse events compared to women studied under a similar protocol without FNB.

Randomized controlled trial of wound complication rates of subcuticular suture vs staples for skin closure at cesarean delivery.

OBJECTIVE: The purpose of this study was to determine the wound complication rates and patient satisfaction for subcuticular suture vs staples for skin closure at cesarean delivery. STUDY DESIGN: This was a randomized prospective trial. Subjects who underwent cesarean delivery were assigned randomly to stainless steel staples or subcuticular 4.0 Monocryl sutures. The primary outcomes were composite wound complication rate and patient satisfaction. RESULTS: A total of 435 patients were assigned randomly. Staple closure was associated with a 4-fold increased risk of wound separation (adjusted odds ratio [aOR], 4.66; 95% confidence interval [CI], 2.07-10.52; P < .001). Having a wound complication was associated with a 5-fold decrease in patient satisfaction (aOR, 0.18; 95% CI, 0.09-0.37; P < .001). After confounders were controlled for, there was no difference in satisfaction between the treatment groups (aOR, 0.71; 95% CI, 0.34-1.50; P = .63). CONCLUSION: Use of staples for cesarean delivery closure is associated with an increased risk of wound complications. Occurrence of a wound complication is the most important factor that influenced patient satisfaction.

Comprehensive amniotic fluid cytokine profile evaluation in women with a short cervix: which cytokine(s) correlates best with outcome?

OBJECTIVE: The objective of this study was to determine whether an expanded amniotic fluid cytokine profile predicts spontaneous preterm birth in patients with short cervix in the midtrimester. STUDY DESIGN: Amniocentesis was performed on singleton gestations between 16-24 weeks with a cervical length

Is midtrimester short cervix a sign of intraamniotic inflammation?

OBJECTIVE: We sought to determine the relationship between the degree of cervical shortening and intraamniotic inflammation in patients presenting with a midtrimester short cervix. STUDY DESIGN: Amniocentesis was performed on singleton pregnancies between 16-24 weeks' gestation with a sonographic cervical length (CL) 1500 pg/mL, CL of 5 mm had an 86% sensitivity, 85% specificity, 58% positive predictive value, and 96% negative predictive value to predict elevated MCP-1 levels. After excluding patients with intraamniotic infection or labor, findings were similar. CONCLUSION: CL

Fetal fibronectin testing in patients with short cervix in the midtrimester: can it identify optimal candidates for ultrasound-indicated cerclage?

OBJECTIVE: The objective of the study was to determine the relationship between fetal fibronectin (fFN) testing prior to ultrasound-indicated cerclage and obstetric outcome. STUDY DESIGN: Singleton pregnancies between 18 and 24 weeks' gestation with an ultrasound-diagnosed short cervix (< 25 mm) and funneling (> 25%) of the chorioamniotic membranes into the endocervical canal were analyzed. The fFN testing was performed and patients were randomized to cerclage or no-cerclage. Groups were stratified by fFN result. Cerclage patients were compared with no-cerclage patients. The primary outcome was delivery prior to 35 weeks' gestation. RESULTS: Spontaneous preterm birth prior to 35 weeks' gestation occurred in 15 (44.1%) fFN-positive-cerclage patients and 16 (55.2%) fFN-positive no-cerclage patients (P = .45). Similarly, it occurred in 16 (17.8%) fFN-negative cerclage patients and 11 (17%) fFN-no-cerclage patients (P = .99). CONCLUSION: fFN did not identify optimal candidates for cerclage. However, fFN testing before an ultrasound-indicated cerclage aids in counseling patients, anticipating the outcome of pregnancies complicated by cervical shortening.

Shirodkar versus McDonald cerclage for the prevention of preterm birth in women with short cervical length.

The efficacy of Shirodkar cerclage was compared with that of the McDonald procedure for the prevention of preterm birth (PTB) in women with a short cervix. Secondary analysis using data from all published randomized trials including women with a short cervical length (CL) was performed comparing the use of Shirodkar versus McDonald sutures. Analysis was limited to singletons with short CL on transvaginal ultrasound. The primary outcome measure was PTB < 33 weeks. Statistical analysis was performed using bivariate and multivariable techniques. From 607 women randomly assigned in the study, 277 met our inclusion criteria; 127 received Shirodkar and 150 women received McDonald sutures. The mean ( +/- standard deviation) gestational age at delivery was 35.0 +/- 5.3 versus 36.3 +/- 4.7 for the Shirodkar versus McDonald groups, respectively ( p< 0.02). PTB < 33 weeks was seen in 61 (22%) of 277 women; 26 (20%) of 127 in the Shirodkar and 35 (23%) of 150 in the McDonald groups, respectively (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.5 to 1.6). On adjusting for confounders using logistic regression modeling, no significant difference in PTB < 33 weeks was found between the two groups (OR, 0.55; 95% CI, 0.2 to 1.3). In women with short cervical length randomly assigned to receiving cerclage, no significant difference in prevention of PTB was observed using Shirodkar or McDonald's procedures.

Short cervix on ultrasound: does indomethacin prevent preterm birth?

OBJECTIVE: Our aim was to estimate if indomethacin therapy prevents preterm birth (PTB) in women with a short cervical length (CL) on transvaginal ultrasound (TVU). STUDY DESIGN: Individual-level data from all randomized trials including asymptomatic women with a short CL on TVU were analyzed for use of indomethacin at the time of the short CL. The trials eligible would be ones that randomized women with a short CL <25 mm, identified between 14 and 27 weeks. The eligible trials randomized such women to receive either cerclage or no cerclage. Only women who did NOT receive cerclage were analyzed. Exclusion criteria were major fetal anomaly and cerclage. We compared demographics, risk factors, and outcomes in women who, at the time of the short CL, received indomethacin or not. Primary outcome was PTB <35 weeks. RESULTS: Three of the 4 randomized trials identified had databases which recorded indomethacin use at the time of the short CL. A total of 139 women with a short CL <25 mm identified at 14 to 27 weeks were identified. Of these women, 99 (71.2%) received indomethacin, and 40 (28.8%) did not. Demographics and risk factors, including previous PTB (45.5% vs 62.5%; P = .11), were similar in the 2 groups. The primary outcome of PTB <35 weeks occurred in 29.3% (29/99) of women who received indomethacin, and 42.5% (17/40) of women who did not receive indomethacin (RR 0.69, 95% CI 0.44-1.13). PTB <24 weeks occurred in 1.0% (1/99) versus 7.5% (3/40), respectively (RR 0.14; 95% CI 0.02-0.92). Incidence of perinatal death was similar in the 2 groups (6% vs 10%; RR 0.61, 95% CI 0.19-1.95). CONCLUSION: Indomethacin therapy for asymptomatic women who have a short CL <25 mm on TVU at 14 to 27 weeks and do not receive a cerclage did not prevent spontaneous PTB <35 weeks, but did prevent PTB <24 weeks. Further research including larger numbers and a randomized trial design is necessary to further clarify the effectiveness as well as the risks of this therapy.

Does cerclage prevent preterm birth?

Cerclage procedures can be classified according to timing, (elective, urgent, emergent), and anatomic approach (transvaginal and transabdominal). The most current clinical data and the evidence-based recommendations for each type of cerclage procedure are listed.

Cerclage for short cervix on ultrasonography: meta-analysis of trials using individual patient-level data.

OBJECTIVE: Preterm birth is the main cause of perinatal morbidity and mortality. A short cervical length on transvaginal ultrasonography predicts preterm birth. Our aim was to estimate by meta-analysis of randomized trials whether cerclage prevents preterm birth in women with a short cervical length. DATA SOURCES: MEDLINE, PubMed, EMBASE, and the Cochrane Library were searched with the terms "cerclage," "cervical cerclage," "short cervix," "ultrasound," and "randomized trial." We included randomized trials involving the use of cerclage in women with short cervical length on transvaginal ultrasonography using patient-level data. TABULATION, INTEGRATION, AND RESULTS: Four properly conducted trials were identified. In the total population, preterm birth at less than 35 weeks of gestation occurred in 29.2% (89/305) of the cerclage group, compared with 34.8% (105/302) of the no-cerclage groups (relative risk [RR] 0.84, 95% confidence interval [CI] 0.67-1.06). There was no significant heterogeneity in the overall analysis (P = .29). There was a significant reduction in preterm birth at less than 35 weeks in the cerclage group compared with the no-cerclage groups in singleton gestations (RR 0.74, 95% CI 0.57-0.96), singleton gestations with prior preterm birth (RR 0.61, 95% CI 0.40-0.92), and singleton gestations with prior second-trimester loss (RR 0.57, 95% CI 0.33-0.99). There was a significant increase in preterm birth at less than 35 weeks in twin gestations (RR 2.15, 95% CI 1.15-4.01). CONCLUSION: Cerclage does not prevent preterm birth in all women with short cervical length on transvaginal ultrasonography. In the subgroup analysis of singleton gestations with short cervical length, especially those with a prior preterm birth, cerclage may reduce preterm birth, and a well-powered trial should be carried out in this group of patients. In contrast, in twins, cerclage was associated with a significantly higher incidence of preterm birth.

Does the presence of a funnel increase the risk of adverse perinatal outcome in a patient with a short cervix?

OBJECTIVE: This study was undertaken to determine whether the presence of a dilated internal os (funneling or beaking) alters the outcome of patients with a short cervix documented by transvaginal ultrasound in the second trimester. STUDY DESIGN: Between January 1998 and May 2004, all singleton pregnancies with a short cervix (< or =2.5 cm) and no funnel between 16 and 24 weeks' gestational age were identified by query and review of the Lehigh Valley Perinatal Ultrasound Database. These no funnel patients were compared with patients with a short cervix and funnel matched in accordance with cervical length and risk factors. Multiple variables of perinatal outcome were identified and compared between the Funnel and No Funnel groups. Correlations between cervical measurements and gestational age at birth were analyzed. RESULTS: Of the 279 patients with a short cervix identified, 82 were singleton with a T-shaped cervix and no funnel and 82 patients matched with a typical Y-shaped funnel. There was no difference between groups with respect to maternal demographics, previous preterm birth (28.1% No Funnel group vs 36.5% Funnel group, P = .3), prior cervical surgery (24.3% vs 22.0 %, P = .8), gestational age at entry (20.5 +/- 2.1 vs 21.1 +/- 2.4 weeks, P = .1), and cervical length (1.9 +/- 0.4 vs 1.8 +/- 0.5 cm , P = .1). The No Funnel group had significantly less readmissions for preterm labor (43.2% vs 67.1 %, P = .004), chorioamnionitis (2.4% vs 23.2 %, P = .0002), abruption (1.2% vs 13.4 %, P = .007), preterm rupture of membranes (6.1% vs 23.4%, P = .002), and cerclage placement (23.2% vs 43 %, P = .008). The neonates in the no funnel group delivered later (36.2% +/- 4.6 vs 33.8 +/- 5.4 weeks , P = .003), and had less morbidity and mortality (17.1% vs 37.8 %, P = .02) compared with the Funnel group. The width and depth of the funnel did not correlate with perinatal outcome. Cervical length ( R(2) = 0.07, P = .02) and cervical funneling as a categorical variable ( r = 0.3, P = .0002) did correlate with earlier delivery. CONCLUSION: The disruption of the internal os, as documented by funneling, is a significant risk factor for adverse perinatal outcome (ie, preterm labor, chorioamnionitis, abruption, rupture of the membranes, and serious neonatal morbidity and mortality). Cervical funneling is best measured as a categorical variable (present or absent).

Does cerclage location influence perinatal outcome?

OBJECTIVE: The study was undertaken to measure cerclage location within the cervix and to determine whether placement closer to the internal os is related to perinatal outcome. STUDY DESIGN: We analyzed data collected during a randomized trial of cervical cerclage versus no cerclage that was conducted at Lehigh Valley Hospital between May 1998 and June 2001 in women with ultrasound findings of short cervix less than 25 mm or funneling between 16 and 24 weeks' gestation. Women who were randomly assigned to the cerclage arm had cervical measurements performed before cerclage, including dilation of the internal os, depth of membrane prolapse into the endocervical canal, cervical length below any funnel (distal length), and total cervical length (including any funnel). Measurements obtained after cerclage placement included the distance from external os to cerclage (A), and a repeat of the same four measurements. The distance from the external os to the cerclage (A) was divided by the total cervical length (B) and a cerclage to cervical length ratio (A/B) was calculated. The relationship between these measurements and gestational age at birth was assessed by linear regression analysis. RESULTS: Of 150 patients enrolled, 74 received a McDonald cerclage suture. Mean distal cervical length was 1.9+/-0.9 cm before and 2.9+/-1.0 cm after cerclage (P=.001). The mean distance between the cerclage and external os (A) was 1.8+/-0.6 cm; the total cervical length after cerclage (B) was 3.6+/-0.9 cm. The mean cerclage to cervical length ratio (A/B) was 0.5+/-0.1. Linear regression analysis did not demonstrate a correlation between either the cerclage to external os measurement (A) or the cervical length ratio (A/B) and gestational age at birth (R(2)=0.0006 and 0.008, P=.8 and.6, respectively). CONCLUSION: The length of the cervix below the level of cerclage is not related to duration of pregnancy in women treated with cerclage because of ultrasound evidence of cervical effacement.

Preterm delivery: risks versus benefits of intervention.

The objective of this report is to examine the evidence that supports obstetric intervention to prevent preterm birth and to assess the associated neonatal outcomes. The different causes of preterm birth are identified and reviewed. The evidence to support obstetric intervention is examined, and the current protocols for therapy are listed. An example of institutional data review is outlined and includes common neonatal morbidities with comparison to an international data set. This type of review allows clinicians to establish recommendations for obstetric intervention based on neonatal outcome.

Risk factors for preterm delivery in patients demonstrating sonographic evidence of premature dilation of the internal os, prolapse of the membranes in the endocervical canal and shortening of the distal cervical segment by second trimester ultrasound.

OBJECTIVE: To investigate the outcomes and risk factors associated with the second trimester sonographic findings of premature dilation of the internal cervical os, prolapse of the membranes into the endocervical canal and shortening of the distal segment. STUDY DESIGN: Retrospective chart review to identify patients who met the following criteria: (i) gestational age between 16 and 24 weeks; (ii) a vaginal probe ultrasound documenting dilatation of the internal os, prolapsed membranes into the endocervical canal but not extending beyond the external os, and a shortened distal cervix; and (iii) no evidence of increased uterine activity METHODS: Sonographic measurements obtained included: (i) the width of the internal os dilation; (ii) the depth of membranes prolapsed into endocervix (funneling); (iii) the distal cervical length; and (iv) the total cervical length. Patients were stratified into two groups according to gestational age at delivery: the preterm group (< 34 weeks) and the near-term group (> or = 34 weeks). RESULTS: Thirty-seven patients had complete records for analysis and their pregnancies resulted in 47 live births. Eighteen patients were stratified to the near term group and 19 were stratified to the preterm group. There were no stillborn infants and 10 neonatal deaths. Ten patients received cerclage and seven patients delivered at < 34 weeks gestational age. Risk factors found to be significant for preterm delivery included a gestational age at diagnosis of < or = 20 weeks gestation (p = 0.03), dilatation of the internal os > 1.3 cm (p = 0.04), and a composite Benham score > or = 1.0 (p = 0.02). CONCLUSIONS: The sonographic findings of premature dilatation of the internal os, prolapse of the membranes into the endocervical canal and shortening of the distal cervix are associated with a high rate of delivery < 34 weeks (51%) and neonatal death (27%).