Why must an emergency cerclage be performed before 24 weeks of gestation?

Emergency Cerclage Must Be Performed Before 24 Weeks of Gestation

Emergency cerclage is indicated when there is cervical dilation with visible fetal membranes in the second trimester before 24 weeks without signs of infection, labor, or preterm premature rupture of membranes (PPROM). 1

Rationale for the 24-Week Cutoff

• Emergency cerclage is specifically contraindicated beyond 24 weeks of gestation as established by the American College of Obstetricians and Gynecologists 1
• The 24-week threshold represents the transition from periviable to viable gestation, where management priorities shift from pregnancy prolongation to immediate neonatal considerations 2
• Performing cerclage after 24 weeks carries increased risks without demonstrating sufficient benefits in pregnancy outcomes 1, 3

Evidence Supporting Emergency Cerclage Before 24 Weeks

• Emergency cerclage before 24 weeks is associated with:
  • Significant pregnancy prolongation compared to expectant management 1
  • Increased live birth rates 1
  • Improved neonatal survival 1
• In patients with cervical insufficiency before 24 weeks, emergency cerclage represents the principal treatment option for preventing second-trimester loss 4

Risks of Emergency Cerclage After 24 Weeks

• Increased risk of procedure-related complications including:
  • Membrane rupture during the procedure 2
  • Triggering preterm labor 1
  • Potential for introducing infection 2
• Limited evidence for efficacy beyond 24 weeks, with most studies demonstrating benefit focusing on pre-24 week interventions 5

Alternative Management After 24 Weeks

• After 24 weeks, management typically shifts to:
  • Corticosteroids for fetal lung maturity 2
  • Expectant management with close monitoring 2
  • Preparation for potential preterm delivery 2

Special Considerations

• In extremely select cases between 24-28 weeks with significant cervical dilation but without membrane rupture or infection, some centers have reported successful outcomes with emergency cerclage, but this remains controversial and is not standard practice 6
• A recent study examining emergency cerclage at 24-28 weeks showed reduced adverse neonatal outcomes (8.33% vs 26.42%) compared to conservative treatment, but this represents emerging evidence that has not yet been incorporated into guidelines 6

Contraindications to Emergency Cerclage at Any Gestational Age

• Preterm premature rupture of membranes (PPROM) 1, 2
• Signs of intrauterine infection or chorioamnionitis 1
• Active uterine contractions/labor 1
• Significant vaginal bleeding 1
• Lethal fetal anomalies 1

Conclusion

The 24-week cutoff for emergency cerclage represents a critical threshold in obstetrical management based on:

• The transition from periviability to viability
• Evidence showing benefit primarily before this gestational age
• Increased risks with limited proven benefits after 24 weeks
• Shift in management priorities toward immediate neonatal outcomes rather than pregnancy prolongation