Effect of cerclage on labor course and obstetric outcome: a case-control study

Risk of cervical laceration in forceps vs vacuum delivery: A systematic review and meta-analysis

INTRODUCTION

Cervical laceration is an obstetric injury associated with severe postpartum hemorrhage and subsequent spontaneous preterm birth. While operative vaginal delivery is a known risk factor for cervical laceration, it is unclear whether forceps and vacuum deliveries incur the same risk. The aim of this systematic review was to compare the risk of cervical laceration between operative instruments (forceps vs vacuum).

MATERIAL AND METHODS

Medline, Embase, Global Health, CENTRAL, Emcare, and Web of Science were searched from inception until August 2024 with terms related to operative vaginal delivery and cervical laceration. Studies comparing the risk of cervical laceration in individuals undergoing forceps or vacuum delivery were included. Two authors conducted screening, data extraction, and quality assessment of all studies. Random-effects models were used to pool risk ratios across studies and certainty of evidence was assessed using Cochrane methods and the GRADE approach. PROSPERO Registration Number CRD42023421890.

RESULTS

Thirteen studies were eligible for inclusion, 3 randomized controlled trials (RCTs) and 10 observational studies. The overall rate of cervical laceration was 0.35% (990/284218 births) where 1.04% of forceps deliveries (456/43817) were complicated by cervical laceration compared to 0.22% of vacuum deliveries (534/240401). The risk of cervical laceration was 2-5 fold greater in forceps deliveries than in vacuum deliveries: pooled unadjusted risk ratio [RR] 4.83, 95% confidence interval [CI] 1.56-14.98 among RCTs and pooled unadjusted RR 1.89, 95% CI 1.59-2.24 among observational studies. The overall quality of evidence was low to moderate mainly due to the lack of attention to confounding in the included literature. The GRADE assessment indicated that the certainty of evidence was very low for observational studies and moderate for RCTs.

CONCLUSIONS

Low certainty of evidence indicates that forceps deliveries may be associated with an increased risk of cervical laceration compared to vacuum deliveries.

The effect of cervical cerclage on the labor curve

BACKGROUND

Cervical cerclage is an effective intervention to prevent preterm birth among individuals with a history of cervical insufficiency, individuals with a short cervix and history of preterm birth, or individuals with second-trimester painless dilation. Although cerclage reduces the mechanical stress on the cervix by reinforcing it with sutures, cerclage could also cause scarring of the cervix, which may affect the progress of labor.

OBJECTIVE

This study aimed to compare the labor curves between individuals who underwent cerclage and those who did not undergo cerclage.

STUDY DESIGN

This was a retrospective cohort study of individuals with singleton term pregnancy, vertex presentation, and vaginal delivery, using the data from the Consortium on Safe Labor. We excluded individuals with fetal anomalies, stillbirth, or abnormal perinatal outcomes, including 5-minute Apgar score of <7, birth injury, and neonatal intensive care unit admission. We modeled the course of cervical dilation using repeated-measures analysis with a polynomial function and generated smoothed labor curves. An interval-censored regression analysis was performed to estimate traverse times (the elapsed time between 2 cervical dilation measures). The traverse times were compared between individuals who underwent cerclage and those who did not undergo cerclage, controlling for induction of labor and parity.

RESULTS

There were 245 individuals who underwent cerclage and 110,080 individuals who did not undergo cerclage. Individuals who underwent cerclage compared with those who did not undergo cerclage had a similar traverse time from 1 to 6 cm (median, 9.1 vs 10.3 hours; adjusted P=.37) and from 6 to 10 cm (median, 1.5 vs 1.5 hours; adjusted P=.23). Individuals who underwent cerclage compared with those who did not undergo cerclage had a longer traverse time from rupture of membranes to delivery (median, 4.0 vs 3.0 hours; adjusted P<.01).

CONCLUSION

Cervical cerclage did not affect the overall progress of labor.

Vaginal Cerclage: Preoperative, Intraoperative, and Postoperative Management

The role of the cerclage procedure has expanded from its initial application as treatment or prevention of cervical insufficiency to prevention of recurrent spontaneous preterm birth. Although recent prospective studies have clarified the indications for cerclage, additional prospective studies are needed to help define optimal perioperative management. Herein, we review the current data to provide the clinician with the most evidence-based approach to managing patients who require cerclage.

Cervical lacerations in planned versus labor cerclage removal: a systematic review

OBJECTIVE

The aim of this study was to evaluate the incidence of cervical lacerations with cerclage removal planned before labor compared to after the onset of labor by a systematic review of published studies.

STUDY DESIGN

Searches were performed in electronic databases from inception of each database to November 2014. We identified all studies reporting the rate of cervical lacerations and the timing of cerclage removal (either before or after the onset of labor). The primary outcome was the incidence of spontaneous and clinically significant intrapartum cervical lacerations (i.e. lacerations requiring suturing).

RESULTS

Six studies, which met the inclusion criteria, were included in the analysis. The overall incidence of cervical lacerations was 8.9% (32/359). There were 23/280 (6.4%) cervical lacerations in the planned removal group, and 9/79 (11.4%) in the removal after labor group (odds ratio 0.70, 95% confidence interval 0.31-1.57).

CONCLUSIONS

In summary, planned removal of cerclage before labor was not shown to be associated with statistically significant reduction in the incidence of cervical lacerations. However, since that our data probably did not reach statistical significance because of a type II error, further studies are needed.