Cerclage for Twins With Short Cervical Length ≤ 15mm

Cervical Cerclage for Preventing Spontaneous Preterm Birth in Twin Pregnancies With Transvaginal Ultrasound Cervical Length ≤ 15mm: a Study Protocol for a Randomized Clinical Trial

This is a multicenter randomized study designed to determine if ultrasound indicated cerclage reduces the incidence of spontaneous preterm birth <34 weeks in asymptomatic women with twin gestations and cervical length ≤15mm, diagnosed by transvaginal ultrasound between 16 to 23 6/7 weeks of gestation.

Twin pregnancies have 59% incidence of preterm delivery (before 37 weeks of gestation), with increased perinatal mortality and neonatal morbidity. No therapy has proven effective in preventing preterm birth in twins. The transvaginal cervical length (TVCL) performed before 24 weeks have been determined to be the best tool to identified women with twin pregnancy at risk of preterm birth (PTB). When short TVCL is identified before 24 weeks, the risk of preterm birth is 60%-70% for TVCL ≤25mm and 80%-90% for TVCL ≤15mm. There are a small number of case reports of cervical cerclage in twin pregnancies with cervical length ≤15mm that suggest decreased preterm birth by 80%. The investigators' objective is to determine if ultrasound indicated cerclage in reduces the incidence of spontaneous preterm birth <34 weeks and improve perinatal outcome in asymptomatic women with twin gestations and cervical length ≤15mm between 16 to 23 6/7 weeks of gestation.

Inclusion Criteria:

1. Pregnant women more than 18 years of age (limits the participants to female gender)
2. Diamniotic twin pregnancy
3. Asymptomatic
4. Transvaginal cervical length ≤ 15 mm between 16-23 6/7 weeks gestation

Exclusion Criteria:

1. Singleton or higher order than twins multiple gestation
2. Transvaginal cervical length >15mm
3. Cervical dilation with visible amniotic membranes
4. Amniotic membranes prolapsed into the vagina
5. Fetal reduction after 14 weeks form higher order
6. Monoamniotic twins
7. Twin-twin transfusion syndrome
8. Ruptured membranes
9. Major fetal structural anomaly
10. Fetal chromosomal abnormality
11. Cerclage already in place for other indication
12. Active vaginal bleeding
13. Clinical chorioamnionitis
14. Placenta previa
15. Painful regular uterine contractions
16. Labor