Prophylactic Cerclage for Twin Pregnancy With Shortened Cervix

Protective Value of Cervical Cerclage Against Preterm Birth in Twin Pregnancy With Short Cervix. A Randomized Controlled Trial.

This randomized controlled trial is aimed to evaluate pregnancy and neonatal outcomes in twin pregnancies, in which a cervical cerclage is placed due to the shortening of the cervix with or without visible fetal membranes.

Introduction 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 mortality.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 births.5 However, there is growing evidence of beneficial effect of applying cervical cerclage. Based on a few, small, controlled trials, cervical cerclage may extend the pregnancy, if it is applied to a cervix of less than 15 mm.6,7 Such practice is still in need for further validation by well-structured and powered randomized controlled trials.

Rationale:

Pregnant in twins with history suggesting cervical weakness and evidence of shortened cervix in the current pregnancy might get benefit from mechanical support by cervical cerclage in trial to reduce the risk of preterm birth.

Inclusion Criteria:

• Age between 18-45 years.
• Dichorionic twins.
• Transvaginal sonographic cervical length is <25 mm with or without internal os dilatation ≥10 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.