Development and validation of models for predicting preterm birth and gestational latency following emergency cervical cerclage: A multicenter cohort study

INTRODUCTION

Emergency cervical cerclage is a recognized method for preventing mid-trimester pregnancy loss and premature birth; however, its benefits remain controversial. This study aimed to establish preoperative models predicting preterm birth and gestational latency following emergency cervical cerclage in singleton pregnant patients with a high risk of preterm birth.

MATERIAL AND METHODS

We retrospectively reviewed data from patients who received emergency cerclage between 2015 and 2023 in three institutions. Patients were grouped into a derivation cohort (n = 141) and an independent validation cohort (n = 61). Univariate and multivariate logistic and Cox regression analyses were used to identify independent predictive variables and establish the models. Harrell's C-index, time-dependent receiver operating characteristic curves and areas under the curves, calibration curve, and decision curve analyses were performed to assess the models.

RESULTS

The models incorporated gestational weeks at cerclage placement, history of prior second-trimester loss and/or preterm birth, cervical dilation, and preoperative C-reactive protein level. The C-index of the model for predicting preterm birth before 28 weeks was 0.87 (95% CI: 0.82-0.93) in the derivation cohort and 0.82 (95% CI: 0.71-0.92) in the independent validation cohort; The C-index of the model for predicting gestational latency was 0.70 (95% CI: 0.66-0.75) and 0.78 (95% CI: 0.71-0.84), respectively. In the derivation set, the areas under the curves were 0.84, 0.81, and 0.84 for predicting 1-, 3- and 5-week pregnancy prolongation, respectively. The corresponding values for the external validation were 0.78, 0.78, and 0.79, respectively. Calibration curves showed a good homogeneity between the observed and predicted ongoing pregnant probabilities. Decision curve analyses revealed satisfactory clinical usefulness.

CONCLUSIONS

These novel models provide reliable and valuable prognostic predictions for patients undergoing emergency cerclage. The models can assist clinicians and patients in making personalized clinical decisions before opting for the cervical cerclage.

Comparison of two emergency cervical cerclage techniques in twin pregnancies: A retrospective cohort study matched with cervical dilation

OBJECTIVES

This retrospective cohort study aimed to assess the efficacy of emergency cervical cerclage (ECC) performed with the combined McDonald-Shirodkar technique in twin pregnancies between 18 and 26 weeks of pregnancy with painless cervical dilation 1 to 6 cm.

METHODS

A retrospective cohort study matched with the degree of cervical dilation was conducted. The study group (case group) included women with twin pregnancies undergoing combined McDonald-Shirodkar approach with cervical dilation ≥1 cm between 18 to 26 weeks of gestation at four institutions, from December 2015 to December 2022. To minimize confounding factors, we elucidated the causality structure using a directed acyclic graph and performed 1:1 case-control matching. A control group underwent the McDonald approach. The primary outcome was gestational age (GA) at delivery. The secondary outcomes were pregnancy latency; the rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks; and neonatal outcomes. Additional subanalysis was performed by dividing the patients into two subgroups of women with cervical dilation ≥3 cm and <3 cm.

RESULTS

A total of 84 twin pregnancies were managed with either the combined McDonald-Shirodkar approach (case group: n = 42) or the McDonald approach (control group: n = 42). Demographic characteristics were not significantly different in the two groups (P > 0.05). After adjusting for confounders that were represented by a directed acyclic graph, median GA at delivery was significantly higher (30.5 vs 27 weeks; Bate: 3.40 [95% confidence interval (CI), 2.13-4.67], P < 0.001) and median pregnancy latency was significantly longer (56 vs 28 days; Bate: 24.04 [95% CI, 13.31-34.78], P < 0.001) in the case group compared with the control group. Rates of spontaneous preterm birth at <28, <30, <32, and <34 weeks were significantly lower in the case group than in the control group. For neonatal outcomes, there was higher birth weight (1543.75 vs 980 g; Bate: 420.08 [95% CI, 192.18-647.98], P < 0.001) and significantly lower overall perinatal mortality (7.1% vs 31%; adjusted odds ratio, 0.16 [95% CI, 0.04-0.70], P = 0.014) in the case group compared with the control group. When cervical dilation was ≥3 cm, the combined McDonald-Shirodkar procedure can significantly reduce perinatal mortality (8.3% vs 46.7%; adjusted odds ratio, 0.09 [95% CI, 0.01-0.77], P = 0.028), significantly decrease the risk of delivery at <28 and <30 weeks, and prolong GA at delivery and pregnancy latency compared with the McDonald procedure.

CONCLUSIONS

ECC performed with the combined McDonald-Shirodkar procedure in women with twin pregnancies who have cervical dilation 1 to 6 cm in midtrimester pregnancy may reduce the rate of spontaneous preterm birth and improve perinatal and neonatal outcomes compared with the McDonald procedure, especially for twin pregnancies in women with cervical dilation of 3 to 6 cm and prolapsed membranes.

Comparison of two stitches versus one stitch for emergency cervical cerclage to prevent preterm birth in singleton pregnancies

OBJECTIVE

To compare the efficacy of two stitches versus one stitch in women with emergency cervical cerclage.

METHODS

A retrospective case-control study of 26 women with singleton pregnancies who underwent emergency cervical cerclage before 26 weeks. A comparison was made between patients with two stitches versus one stitch at the time of cervical cerclage placement. The primary outcome was gestational age (GA) at delivery and preterm birth (PTB) before 37, 34, 32, 28, and 24 weeks.

RESULTS

Average GA at delivery in the two-stitches group was significantly greater than in the one-stitch group (32.71 ± 5.54 weeks vs 27.99 ± 4.70 weeks, P = 0.028). There were significant decreases in the incidence of spontaneous PTB at <34 weeks and less than 32 weeks in the two-stitches group (P = 0.034; P = 0.013, respectively). The neonatal intensive care unit (NICU) admissions rate and length of stay in the NICU in the two-stitches group were significantly reduced (P = 0.035 and P = 0.018, respectively). However, there was no significant difference in neonatal mortality between the two groups.

CONCLUSION

Compared with emergency cervical cerclage placement with one stitch, the procedure with two stitches can prolong the pregnancy and improve the neonatal prognosis more effectively.

Emergency cervical cerclage in twin and singleton pregnancies with 0-mm cervical length or prolapsed membranes

INTRODUCTION

Cervical cerclage is controversial in twin pregnancies, although recent data from the USA supports its use where "physical examination-indicated". Limited data exist, however, in the extreme situation of 0-mm ultrasound-measured cervical length or even prolapsed membranes. This research compares the success of emergency cervical cerclage in multiple and singleton pregnancies.

MATERIAL AND METHODS

This is a retrospective cohort study of all such cerclages performed at a tertiary hospital over a 15-year period. "Emergency" was where transvaginal ultrasound-assessed cervical length was 0 mm, with amniotic membranes at or beyond the external cervical os. Exclusion criteria were clinical or biochemical evidence of infection, regular contractions, bleeding, ruptured membranes, or gestation beyond 24⁺⁰  weeks. The primary outcome, or "success", was defined as birth >27⁺⁶  weeks of gestation, with the neonate alive 28 days later with no markers of adverse outcome (seizures, periventricular leukomalacia, intracranial hemorrhage more than Grade 2, or necrotizing enterocolitis). Demographic and cerclage variables were assessed against the primary outcome. Variables correlated with success were analyzed between multiple and singleton pregnancies. Comparison of all adverse outcomes was then adjusted using logistic regression.

RESULTS

A total of 135 pregnancies were included (107 singletons and 28 multiples [all twins]). Success was achieved in 79 (58.5%; 57.9% in singletons, 60.7% in twins). Nulliparity, in utero transfer, symptoms, prolapsed membranes, and dilation more than 3 cm were predictors of failure, but twin pregnancy was not. After controlling for potential confounding variables, there was no significant difference in measures of success between singleton and twin pregnancies, apart from higher rates of neonatal unit admission.

CONCLUSIONS

Emergency cervical cerclage, even in extreme situations, is as effective in twin pregnancies as it is in singletons.

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.

Rescue Cervical Cerclage : Prevention of a Previable Birth

Rescue cervical cerclage can effectively prolong a nonviable gestation to viability, if done correctly in chosen patients after appropriate counseling. Here, we present a case study of an antenatal woman with advanced cervical changes at 24 weeks who benefited from the rescue cervical cerclage procedure to have a successful pregnancy outcome.