Ultrasound-Indicated Cervical Cerclage Efficacy Between 16 and 28 Weeks of Gestation in Twin Pregnancy: Retrospective Cohort Study

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.

The effectiveness of cervical cerclage in twin pregnancies with a mid-trimester short cervix: A retrospective cohort study

OBJECTIVE

To analyze the effectiveness of cerclage in twin pregnancies with a short cervix.

STUDY DESIGN

Retrospective cohort study performed in two University Institutions in Valencia (Spain) with two different protocols for the management of asymptomatic dichorionic diamniotic twin pregnancies with mid-trimester cervical length ≤ 25 mm: treatment with indomethacin, antibiotics and cerclage (cerclage group) (N = 43) versus expectant management (control group) (N = 37).

RESULTS

The initial cervical length was similar in both groups but detection of a short cervix was performed earlier in the cerclage group (21.6 vs 24.1 weeks, p < 0.001). Women with cerclage had a greater pregnancy latency (12.5 vs. 7.7 weeks, p < 0.001); higher gestational age at delivery (34.1 vs. 31.8 weeks, p < 0.04); less spontaneous preterm birth (SPB) < 28 weeks (11.6 % vs 37.8 %, p < 0.009); higher birthweight (2145 vs 1733 g, p < 0.001); lower birthweight < 1500 g (12.5 % vs 40.0 %, p < 0.001); less admissions to the neonatal intensive care unit (NICU) (24.1 % vs 43.3 %, p < 0.03); shorter stay at NICU (25.6 vs 49.4 days, p < 0.02); lower respiratory distress requiring mechanical ventilation (14.9 % vs 36.5 %, p < 0.02); fewer patent ductus arteriosus (8.9 % vs 26.9 %, p < 0.008); and lower composite adverse neonatal outcome (26.6 % vs. 44.8 %, p < 0.03). Cerclage and gestational age at diagnosis were the only independent predictors of SPB < 32 and < 28 weeks by multivariate analysis. The cumulative data in the literature show promising beneficial effects of cerclage.

CONCLUSION

Our data suggest that cerclage in asymptomatic twin pregnancies with a short cervix may reduce the earliest SPB and may improve neonatal outcome.

Screening and Prevention of Preterm Birth in Twin Pregnancies

Twins represent 3.2% of all live births. However, they account for 20% of all preterm deliveries, 60% delivering <37 weeks, 10.7% <32 weeks, and 5 times higher risk of infant death. Risk factors for preterm birth (PTB) include the history of preterm delivery, monochorionic twins, short cervical length, and cervical surgery. Transvaginal cervical length <24 weeks is the best tool to predict PTB. Only vaginal progesterone in women with transvaginal cervical length <25 mm and physical exam indicated cerclage in women with cervical dilation >1 cm have shown a significant decrease in PTB and improvement in neonatal outcomes.

Cervical cerclage for prevention of preterm birth and adverse perinatal outcome in twin pregnancies with short cervical length or cervical dilatation: A systematic review and meta-analysis

BACKGROUND

The optimal approach to prevent preterm birth (PTB) in twins has not been fully established yet. Recent evidence suggests that placement of cervical cerclage in twin pregnancies with short cervical length at ultrasound or cervical dilatation at physical examination might be associated with a reduced risk of PTB. However, such evidence is based mainly on small studies thus questioning the robustness of these findings. The aim of this systematic review was to determine the role of cervical cerclage in preventing PTB and adverse maternal or perinatal outcomes in twin pregnancies.

METHODS AND FINDINGS

Key databases searched and date of last search: MEDLINE, Embase, and CINAHL were searched electronically on 20 April 2023. Eligibility criteria: Inclusion criteria were observational studies assessing the risk of PTB among twin pregnancies undergoing cerclage versus no cerclage and randomized trials in which twin pregnancies were allocated to cerclage for the prevention of PTB or to a control group (e.g., placebo or treatment as usual). The primary outcome was PTB <34 weeks of gestation. The secondary outcomes were PTB <37, 32, 28, 24 weeks of gestation, gestational age at birth, the interval between diagnosis and birth, preterm prelabor rupture of the membranes (pPROM), chorioamnionitis, perinatal loss, and perinatal morbidity. Subgroup analyses according to the indication for cerclage (short cervical length or cervical dilatation) were also performed. Risk of bias assessment: The risk of bias of the included randomized controlled trials (RCTs) was assessed using the Revised Cochrane risk-of-bias tool for randomized trials, while that of the observational studies using the Newcastle-Ottawa scale (NOS). Statistical analysis: Summary risk ratios (RRs) of the likelihood of detecting each categorical outcome in exposed versus unexposed women, and (b) summary mean differences (MDs) between exposed and unexposed women (for each continuous outcome), with their 95% confidence intervals (CIs) were computed using head-to-head meta-analyses. Synthesis of the results: Eighteen studies (1,465 twin pregnancies) were included. Placement of cervical cerclage in women with a twin pregnancy with a short cervix at ultrasound or cervical dilatation at physical examination was associated with a reduced risk of PTB <34 weeks of gestation (RR: 0.73, 95% CI [0.59, 0.91], p = 0.005 corresponding to a 16% difference in the absolute risk, AR), <32 (RR: 0.69, 95% CI [0.57, 0.84], p < 0.001; AR: 16.92%), <28 (RR: 0.54, 95% [CI 0.43, 0.67], 0.001; AR: 18.29%), and <24 (RR: 0.48, 95% CI [0.23, 0.97], p = 0.04; AR: 15.57%) weeks of gestation and a prolonged gestational age at birth (MD: 2.32 weeks, 95% [CI 0.99, 3.66], p < 0.001). Cerclage in twin pregnancy with short cervical length or cervical dilatation was also associated with a reduced risk of perinatal loss (RR: 0.38, 95% CI [0.25, 0.60], p < 0.001; AR: 19.62%) and composite adverse outcome (RR: 0.69, 95% CI [0.53, 0.90], p = 0.007; AR: 11.75%). Cervical cerclage was associated with a reduced risk of PTB <34 weeks both in women with cervical length <15 mm (RR: 0.74, 95% CI [0.58, 0.95], p = 0.02; AR: 29.17%) and in those with cervical dilatation (RR: 0.68, 95% CI [0.57, 0.80], p < 0.001; AR: 35.02%). The association between cerclage and prevention of PTB and adverse perinatal outcomes was exclusively due to the inclusion of observational studies. The quality of retrieved evidence at GRADE assessment was low.

CONCLUSIONS

Emergency cerclage for cervical dilation or short cervical length <15 mm may be potentially associated with a reduction in PTB and improved perinatal outcomes. However, these findings are mainly based upon observational studies and require confirmation in large and adequately powered RCTs.

Efficacy of ultrasound-indicated cerclage in twin pregnancies: a retrospective case-control study matched by cervical length

BACKGROUND

Twin pregnancies with a progressively shortening cervix in the midterm pregnancy have an increasing risk for spontaneous preterm birth. Currently, there is no known effective method to prevent preterm birth among those women, and the use of an ultrasound-indicated cerclage in twin pregnancies is still controversial.

OBJECTIVE

This study aimed to estimate whether a combination of ultrasound-indicated cerclage, indomethacin, and antibiotics in twin pregnancies between 18 and 26 weeks' gestation could extend the pregnancy, reduce the risk for spontaneous preterm birth, and improve perinatal and neonatal outcomes.

STUDY DESIGN

A retrospective cohort study was conducted. The ultrasound-indicated cerclage group included twin pregnancies with a transvaginal cervical length <25 mm that underwent cerclage at 18 to 26 weeks of gestation in the Women's Hospital, Zhejiang University School of Medicine, from December 2015 through August 2021. Twin pregnancies in our study that underwent cerclage also received antibiotics and indomethacin. A control group of twin pregnancies that were managed expectantly were matched with the treatment group in terms of transvaginal cervical length at diagnosis (±3 mm), gestational age at presentation of diagnosis (±3 weeks), and maternal age (±5 years). An additional subanalysis was performed in which the patients were divided into 2 subgroups based on transvaginal cervical length of either <15 mm or between 15 and 24 mm. The primary outcome was gestational age at delivery. The secondary outcomes were pregnancy latency, the rate of spontaneous preterm birth at <28, <32, <34, <36 weeks' gestation, and neonatal outcomes.

RESULTS

A total of 90 twin pregnancies with a transvaginal cervical length <25 mm were managed with either a cerclage (ultrasound-indicated cerclage group, n=45) or expectantly (control group, n=45). Demographic characteristics were not significantly different between the groups. When compared with the control group, the gestational age at delivery was significantly higher (33.11±3.16 vs 30.22±4.12 weeks; P=.001) and the pregnancy latency was significantly longer (72.40±22.51 vs 45.56±28.82 days; P<.001) in the ultrasound-indicated cerclage group. The rates of spontaneous preterm birth at <28, <32, <34, and <36 weeks' gestation were significantly lower in the ultrasound-indicated cerclage group than in the control group. In terms of neonatal outcomes, there were significant reductions in the overall perinatal mortality (4.4% vs 20.0%; P<.001), neonatal intensive care unit admissions (69.0% vs 92.6%; P<.001), and composite adverse neonatal outcomes (43.7% vs 64.7%; P=.010) for the ultrasound-indicated cerclage group when compared with the control group. In the subgroup of women with a transvaginal cervical length of between 15 and 24 mm (with 21 in the ultrasound-indicated cerclage group vs 21 controls), the data were adjusted for maternal age, pregestational body mass index, in vitro fertilization, operative hysteroscopy, previous cervical surgery, previous spontaneous preterm birth, white blood cell counts, C-reactive protein level, neutrophil to lymphocyte ratio, and the shortest transvaginal cervical length measured at diagnosis. In ultrasound-indicated cerclage group, gestational age at delivery was significantly higher (32.95±3.81 vs 30.24±4.01 weeks; beta, 3.34; 95% confidence interval, 0.14-6.55; P=.042), pregnancy latency was significantly prolonged (77.19±24.81 vs 48.52±29.67 days; beta, 33.81; 95% confidence interval, 12.29-55.34; P=.003), and the rates of spontaneous preterm birth <36 weeks' gestation (57.1% vs 95.2%; adjusted odds ratio, 0.03; 95% confidence interval, 0.01-0.69; P=.029) was significantly decreased, and for neonatal outcomes, there were significant reductions in neonatal intensive care unit admissions (53.7% vs 96.7%; adjusted odds ratio, 0.04; 95% confidence interval, 0.01-0.32; P=.003) and the composite adverse neonatal outcomes (39.0% vs 73.3%; adjusted odds ratio, 0.24; 95% confidence interval, 0.08-0.68; P=.008) in the ultrasound-indicated cerclage group when compared with the control group. In the subgroup of women with a transvaginal cervical length <15 mm, gestational age at delivery was higher (33.25±2.52 vs 30.00±4.33 weeks; beta, 3.96; 95% confidence interval, 1.51-6.42; P=.002), pregnancy latency was significantly prolonged (68.21±19.85 vs 42.96±28.43 days; beta, 30.11; 95% confidence interval, 12.42-47.81; P=.001), rates of spontaneous preterm birth at <32 weeks (16.7% vs 54.2%; adjusted odds ratio, 0.10; 95% confidence interval, 0.01-0.61; P=.020) and <34 weeks (54.2% vs 83.3%, adjusted odds ratio, 0.08; 95% confidence interval, 0.01-0.66; P=.019) of gestation was significantly decreased, and neonatal birthweight was significantly increased (2023.96±510.35 vs 1421.77±611.40 g; beta, 702.40; 95% confidence interval, 297.02-1107.78; P=.001) in the ultrasound-indicated cerclage group when compared with the control group.

CONCLUSION

Cerclage among women with twin pregnancies with a transvaginal cervical length <25 mm may reduce the rate of spontaneous preterm birth and improve perinatal and neonatal outcomes when compared with expectant management. It is worth noting that even with a short transvaginal cervical length of 15 to 24 mm, cerclage will significantly decrease the risk of delivery at <36 weeks' gestation and prolong pregnancy latency. Among women with a short transvaginal cervical length <15 mm, cerclage will significantly decrease the risk of delivery at <32 and <34 weeks' gestation and prolong pregnancy latency.