Indications for Cervical Cerclage
Cervical cerclage is primarily indicated for women with a history of cervical insufficiency, those with a short cervical length and prior preterm birth, and in select emergency situations to prevent preterm birth and reduce neonatal morbidity and mortality.
History-Indicated Cerclage
- Women with a history of three or more second-trimester pregnancy losses or extreme premature deliveries without other identified causes should be offered elective cerclage at 12-14 weeks of gestation 1
- Women with a history of one or more second-trimester losses related to painless cervical dilation 2
- Women who have undergone trachelectomy should have abdominal cerclage placement 1
Ultrasound-Indicated Cerclage
- Singleton pregnancies with prior spontaneous preterm birth and cervical length ≤25 mm before 24 weeks gestation 1, 3
- Women with a history of 1-2 prior mid-trimester losses or extreme premature deliveries should undergo serial cervical length assessment by ultrasound 1
- Cervical cerclage should be considered if cervical length shortens to ≤25 mm before 24 weeks 3, 4
Emergency/Rescue Cerclage
- May be considered in women with cervical dilation <4 cm without contractions before 24 weeks gestation 1
- For women presenting with exposed membranes prolapsing through the cervical os (individualized basis due to high risk of infection) 4
Transabdominal Cerclage Indications
- Previous failed transvaginal cerclage (history or ultrasound-indicated) with subsequent spontaneous singleton delivery before 28 weeks gestation 5
- Women who have undergone trachelectomy 1
- Women with anatomic limitations preventing successful vaginal cerclage placement 5
When Cerclage is NOT Indicated
- Incidental finding of short cervix by ultrasound without prior risk factors for preterm birth 1
- Multiple gestations, even with history of preterm birth 1
- Multiple gestations with short cervical length 1
Timing of Cerclage Placement
- History-indicated cerclage: 12-14 weeks gestation 1
- Ultrasound-indicated cerclage: When cervical length ≤25 mm before 24 weeks 3, 1
- Transabdominal cerclage: Can be performed before pregnancy or in first trimester with similar outcomes; can be considered up to 22 weeks gestation 5
Pre-Cerclage Evaluation
- Urinalysis for culture and sensitivity and vaginal cultures for bacterial vaginosis should be obtained at first obstetric visit 1
- Any infections should be treated before cerclage placement 1
Post-Cerclage Management
- Routine transvaginal cervical length screening is not recommended for patients with transabdominal cerclage 5
- For patients at risk of recurrent spontaneous preterm birth with transabdominal cerclage, vaginal progesterone may be considered 5
- Cesarean delivery between 37 0/7 and 39 0/7 weeks is suggested for patients with transabdominal cerclage 5
Important Considerations
- The decision between laparoscopic or open transabdominal cerclage depends on gestational age, technical feasibility, available resources, and expertise 5
- In women with a short cervix (<10 mm), cerclage has been shown to decrease preterm birth rates at <35 weeks compared to no cerclage (39.5% vs 58.0%) 3
- Meta-analysis shows cerclage placement resulted in a 30% decrease in preterm birth <35 weeks with significantly decreased rates of preterm birth before 37,32,28, and 24 weeks 3
Remember that maternal-fetal medicine consultation is recommended for counseling patients who may be candidates for transabdominal cerclage and those who have undergone the procedure 5.