Prophylactic Cervical Cerclage in Twin Pregnancies With Non-shortened Cervix

The Value of Prophylactic Cervical Cerclage Against Preterm Birth in Twin Pregnancies With History of Preterm Birth and Non-shortened Cervix: A Randomized Controlled Trial

This randomized controlled trial is aimed to assess the protective value of prophylactic cervical cerclage against preterm birth in twin pregnancies with history of one or more preterm births without having cervical shortening in the current pregnancy.

Multiple pregnancies are high-risk pregnancies and usually associated with an increased risk of neonatal morbidity and mortality, mainly due to preterm births. Preterm births occur in 50% of twin pregnancies and the mean gestational age for delivery is 35.3 weeks. Ten percent of all twin births take place before 32 weeks of gestation.1 Preterm births are responsible for more than 70% of all neonatal and infant deaths.2 Prematurity can have serious consequences for the child, such as hearing difficulties, vision impairment, learning disabilities, reduced IQ, and cerebral palsy. A cervical length of ≤25 mm in twin pregnancies is a good predictor of a spontaneous preterm birth when measured around 24 weeks of gestation.3,4 Numerous interventions have been attempted in order to prevent preterm births in twin gestations, but until now, no intervention has been effective. Use of cerclage in twin pregnancies is controversial. Some experts claim that placing a cervical cerclage could increase the risk of preterm births5, Fuchs and Senat6 concluded that cervical cerclage in asymptomatic twins did not reduce the risk of PTB. This conclusion came depending on small sample sized randomized trail done on less than 50 patients.7 Available meta-analytic data remained of limited value in view of the few and small clinical studies that were included.

Although the current meta-analyses indicate the lack of efficacy of cerclage in twin pregnancies, data from the US Standard Certificate of Live Birth indicated that roughly 10% of triplets and 1.3% of twins are still receiving cerclage.8 Some authors compared the efficacy of cerclage in twin pregnancies and singleton pregnancies and showed that women with twin pregnancies who received cerclage might show beneficial obstetric outcomes similar to those of women with singleton gestations.9,10 Such practice is still in need for further validation by well-structured and powered randomized controlled trials.

Inclusion Criteria:

• Age between 18-50 years.
• Dichorionic twins.
• History of ≥1 preterm birth.
• Transvaginal sonographic cervical length is ≥25 mm at 14-20 weeks gestational age.
• Asymptomatic.

Exclusion Criteria:

• Triplets and quadruplets.
• Monochorionic twins.
• Threatened/ inevitable miscarriage
• Bulging membranes through the external os.
• Extremes of age.
• Major fetal anomalies.
• Known cases with uterine anomalies e.g. bicornuate uterus, uterus didelphis… etc.
• Fetal demise.
• Fetal reduction in the current pregnancy.