Randomized Study of Pessary Versus Standard Management in Women With Increased Chance of Premature Birth
Condition: Preterm Birth
MeSH terms: Premature Birth
Study type: Interventional
Phase: Phase 3

Summary: 
      The aim of the study is to determine the effect of cerclage pessary on the incidence of
      spontaneous delivery between randomization (at 20-24+6 weeks) and 33+6 weeks in asymptomatic
      women with singleton pregnancies found at routine mid-trimester screening to have a cervix of
      <25 mm in length and in twin pregnancies.
    

Detailed description: 
      Prematurity is responsible for more than half of all neonatal deaths and whilst advances in
      neonatal care have dramatically improved survival of extremely premature infants, there
      remains a significant risk of handicap and disability in survivors and an associated social
      and economic burden.

      In singleton pregnancies the rate of spontaneous premature birth before 34 weeks is about 1%
      and the risk of spontaneous early delivery is inversely related to cervical length. The group
      with cervix of 1-15 mm accounted for 28% of all spontaneous deliveries before 34 weeks and
      those with cervix of 16-25 mm accounted for 21%. The rate of spontaneous premature birth
      before 34 weeks is about 13% in twin pregnancies.

      Potential methods for the prevention of preterm delivery include bed rest, cervical cerclage
      and prophylactic administration of progesterone. The prophylactic administration of
      progesterone beginning in mid-gestation to women who previously had a premature birth and in
      those with a short cervix has been shown to reduce the rate of spontaneous preterm birth
      before 34 weeks. On the other hand, randomized studies reported that, in twin pregnancies,
      bed rest was associated with a significant increase, rather than decrease, in the rate of
      early preterm delivery.

      There is some evidence that the rate of premature birth can be dramatically reduced by the
      insertion of a vaginal pessary (cerclage pessary, CE0482, MED/CERT ISO 9003 / EN 46003).

      This will be a multicenter trial in the UK and other countries. During routine ultrasound
      scan at 20-24 weeks of gestation for examination of fetal anatomy and growth, all women with
      twin pregnancy or with singleton pregnancy found to have a cervix of <25 mm in length and
      where the fetuses are found to be alive with no major abnormalities, severe twin to twin
      transfusion syndrome or severe fetal growth restriction in one of the fetuses (in the case of
      twin pregnancy), will be invited to participate in a randomized trial of standard management
      vs vaginal insertion of a cerclage pessary. For singleton pregnancy, in both arms the
      patients with cervical length <15 mm will be given prophylactic progesterone (200 mg vaginal
      capsule per night up to 34 weeks). Randomization and insertion of the pessary (in those
      allocated to this group) will be carried out within 5 days after the 20-24 weeks scan.

      The pessary will be removed by a simple vaginal examination at 37 weeks or earlier before
      medically indicated preterm induction of labor or elective cesarean section. The pessary will
      also be removed in women in preterm labor not responding to tocolytic therapy. In
      monochorionic twins some obstetricians advise that delivery is carried out at around 36
      weeks.
    

Intervention name(s): Vaginal pessary (CE0482, MED/CERT ISO 9003 / EN 46003)
Intervention type(s): Device
Intervention description(s): Inserted from randomization till 36-37 weeks of gestation
Other intervention name(s): Vaginal pessary, CE0482, MED/CERT ISO 9003 / EN 46003
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Prevention
Keywords: Twins; Short cervix; Preterm birth; Vaginal pessary