BACKGROUND AND PURPOSE:

• Roman et al. (AJOG, 2020) sought to determine if physical exam-indicated cerclage reduced the incidence of preterm birth in asymptomatic women with twin gestations and cervical dilation prior to 24 weeks

METHODS:

• Multicenter, parallel-group, open-label, randomized controlled trial
• Participants
  • Twin pregnancy | 16w0d to 23w6d
  • Asymptomatic cervical dilation from 1 to 5 cm
• Exclusion criteria
  • Monochorionic-monoamniotic pregnancy | Selective FGR | TTTS | Major fetal and genetic anomalies | Placenta previa | Labor | Chorioamnionitis
• Randomization 1:1 to 2 groups
  • Cerclage placed under anesthesia
    • Additional interventions such as amnioreduction, indomethacin, antibiotics or suture selection left to physician discretion
  • No cerclage
• Study design
  • 8 centers | July 2015 to July 2019
  • Data were analyzed as intention to treat
• Statistical Analysis
  • To detect a reduction in the incidence of PTB < 34 weeks from 80% to 40% with cerclage group
  • Power 80% | Significance level 5%
  • Sample size required: 46 subjects | Total of 52 to account for participant drop out rate
• Primary outcome
  • Incidence of preterm birth <34 weeks
• Secondary outcomes
  • Preterm birth <32, <28 and <24 weeks
  • Interval from diagnosis to delivery
  • Perinatal mortality

RESULTS:

• Following interim analysis, the Data Safety Monitoring Board recommended stopping the trial due to significant decrease in perinatal mortality in the cerclage group
• A total of 30 women were included
  • Cerclage: 17 women (4 women in this group did not received the surgical procedure)
  • No cerclage: 13 women
• All women in cerclage group received
  • Indomethacin: 50 to 100mg loading dose followed by 25 to 50 mg every 6 hours for 48 hours
  • Antibiotics: 12 cephalosporin | 1 clindamycin/ gentamycin | 1 azithromycin
• The incidence of preterm birth was significantly decreased in the cerclage group
  • Preterm birth <34 weeks
    • Cerclage: 70% (12 out of 17 women)
    • No cerclage: 100% (13 out of 13 women)
    • RR 0.71 (95% CI, 0.52 to 0.96)
  • Preterm birth <32 weeks
    • Cerclage: 64.7% (11 out of 17 women)
    • No cerclage: 100% (13 out of 13 women)
    • RR 0.65 (95% CI, 0.46 to 0.92)
  • Preterm birth <28 weeks
    • Cerclage: 41% (7 out of 17 women)
    • No cerclage: 84% (11 out of 13 women)
    • RR 0.49 (95% CI, 0.26 to 0.89)
  • Preterm birth <24 weeks
    • Cerclage: 30% (5 out of 17 women)
    • No cerclage: 84% (11 out of 13 women)
    • RR 0.35 (95% CI, 0.16 to 0.75)
• The mean gestational age at delivery was later in the cerclage group (p<0.01)
  • Cerclage: 29.05±1.7 weeks
  • No cerclage: 22.5±3.9 weeks
• The mean interval from diagnosis of cervical dilation to delivery was longer in the cerclage group (p=0.02)
  • Cerclage: 8.3±5.8 weeks
  • No cerclage: 2.9±3.0 weeks
• Perinatal mortality was significantly reduced in the cerclage group
  • Cerclage: 17.6% (6 out of 34)
  • No cerclage: 77% (20 out of 26)
  • RR 0.22 (95% CI, 0.1 to 0.5)

CONCLUSION:

• Authors recognize limitations in this study, including sample size that was smaller than initial calculations due to early termination of the trial  
• Preterm birth was significantly decreased in twin pregnancies that received physical exam-indicated cerclage, indomethacin, and antibiotics <24 weeks
  • 50% decrease in very early preterm birth <28 weeks
  • 78% decrease in perinatal mortality

Learn More – Primary Sources:

Physical Exam Indicated Cerclage in Twin pregnancy: a Randomized Controlled Trial

Related ObG Topics:

Cervical Cerclage – Professional Recommendations

Preventing Preterm Birth in Twins – What works?

Can Obstetric History Predict Preterm Birth Risk in Twins?

Progesterone, Cerclage or Pessary for Prevention of Preterm Birth: A Comparison