CLINICAL ACTIONS:

ACOG defines cervical insufficiency as “the inability of the uterine cervix to retain a pregnancy in the absence of the signs and symptoms of clinical contractions, or labor, or both in the second trimester.” In addition, ACOG separates out indication for cerclage in to 3 categories

• History: ≥1 of the following
  • Second trimester pregnancy losses related to painless cervical dilation and no history of labor or abruption
  • Previous second trimester cerclage for painless cervical dilation
• Physical Examination: Also known as ‘physical examination–indicated cerclage’, ‘rescue cerclage’ and ’emergency cerclage’
  • Patient presents with painless second trimester cervical dilation
• Ultrasound: Cervical length shortening and history of preterm birth
  • Singleton pregnancy
  • Prior spontaneous preterm birth (<34 weeks)
  • Cervical length:  <25 mm (at <24 weeks)

Timing of Cerclage Placement

• History-indicated cerclage
  • Place between 12 and 14 weeks after confirmation of pregnancy viability
• Ultrasound or exam-indicated cerclage
  • May be placed prior to 23 weeks

Risk Factors

• Prior PTB
• Repeated cervical dilation
• Cervical procedures (including cone and LEEP)
• Cervical laceration
• Urogenital abnormalities

SYNOPSIS:

Clinically, cervical insufficiency is painless dilation and recurrent mid-trimester losses without signs of preterm labor (PTL), PPROM, or infection. Patient history may include superimposed symptoms (i.e. bleeding, pressure), therefore a judicious review of records is advised.  Those with a history of prior preterm birth can benefit from cervical length screening to appropriate guide selected patients for cerclage.

KEY POINTS:

Ultrasound Indicated Cerclage with Prior History of Preterm Birth <34 weeks and cervical length <25 mm before 24 weeks  

• Cerclage associated with
  • Decreased preterm birth 
  • Improved neonatal outcomes  
• No history of preterm birth
  • Cerclage for short cervix at <24 weeks has not been associated with improved preterm birth rates    
• Evidence from research studies
  • There is no demonstrated difference in efficacy of McDonald versus Shirodkar techniques

‘Emergency’ Cerclage (Exam indicated)

• There is literature, including a meta-analysis (Obstet Gynecol, 2015), to support ’emergency’ or ‘rescue’ cerclage
  • Neonatal survival
    • Cerclage: 71% survival
    • No cerclage: 43% survival
    • Relative risk 1.65 (95% CI 1.19 to 2.28)
  • Prolongation of pregnancy
    • Mean difference: 33.98 days (95% CI, 17.88 to 50.08)
  • Authors note significant limitations including quality of data and only 1 RCT included

After clinical examination to rule out uterine activity, or intraamniotic infection, or both, physical examination-indicated cerclage placement (if technically feasible) in patients with singleton gestations who have cervical change of the internal os may be beneficial

Additional Interventions

• Evidence does not support use of the following after cerclage placement
  • Serial cervical length measurements
  • Antibiotics
  • Prophylactic tocolysis

Cerclage Removal

• Remove transvaginal McDonald cerclage at 36 to 37 weeks
• Cesarean delivery planned for ≥39 weeks
  • May be removed at time of delivery
  • Consider possibility of spontaneous labor between 37 and 39 weeks
• McDonald cerclage may be removed in the office
• PPROM
  • Removal or retention “is reasonable”
  • Prolonged antibiotic prophylaxis >7 days not recommended if suture is retained
• Preterm labor
  • Diagnosis may be more difficult with cerclage in place

Routine management of preterm labor should be followed for patients with symptomatic preterm labor

If cervical change, painful contractions, or vaginal bleeding progress, cerclage removal is recommended

Learn More – Primary Sources:

ACOG Practice Bulletin 142: Cerclage for the Management of Cervical Insufficiency

Physical Examination–Indicated Cerclage: A Systematic Review and Meta-analysis

Related ObG Topics:

Meta-analysis: Cerclage for Short Cervix but Without History of Preterm Birth 

Progesterone or Cerclage in Preterm Prevention in Women with Previous Preterm Birth and Short Cervix?

The Role of Routine Cervical Length Screening For Preterm Birth Prevention

SMFM and Choosing Wisely: Practices That Doctors and Patients Should Question