Financial/business decision by Sponsor to not proceed with this study

A prospective randomized control trial that will compare cervical cerclage plus vaginal progesterone to vaginal progesterone along in twin pregnancies complicate by a short cervix (\

A prospective Randomized Trial that will test whether treatment with cervical cerclage plus vaginal progesterone improves pregnancy outcomes among women with twin pregnancy at 16 0/7 to 25 6/7 weeks of gestation who have a cervical length (CL) of 0.1 to 15.0 mm on transvaginal ultrasound exam, the rate of preterm birth at less than 32 weeks of gestation (PTB<32 wks.) and the rate of adverse perinatal outcome will be lower in those treated with cervical cerclage plus vaginal progesterone than in those treated with vaginal progesterone alone.

Inclusion Criteria:

• Twin pregnancy (see Exclusion Criterion (a) below re: monochorionic twins)
• Gestational age 16 0/7 to 25 6/7 weeks at time of enrollment by best-estimated age.
• Cervical length 0.1 to 15.0 mm on transvaginal ultrasound examination. (Cervical length is taken to mean the length of the closed portion of the cervical canal.

Exclusion Criteria:

• Maternal age less than 18 years
• Monochorionic twins (such as monochorionic-diamniotic, monochorionic-monoamniotic, or conjoined twins)
• Rupture of membranes, either twin
• One or both twins has no cardiac activity
• One or both twins has known or suspected major malformation, aneuploidy, or polyhydramnios
• Maternal congenital uterine anomaly (such as bicornuate uterus, unicornuate uterus)
• Pregnancy started as triplets or higher-order multifetal gestation and then reduced to twins, either spontaneously or via procedure
• Symptomatic uterine contractions, 6 or more per hour
• Ongoing bleeding from uterus
• Patient declines to consider cerclage
• Patient declines treatment with vaginal progesterone
• Allergy to progesterone or peanuts (because the vaginal progesterone formulation used will be a capsule of micronized progesterone in peanut oil.)
• Cerclage is already in place
• Cerclage placement is judged to be technically impossible
• Patient has a history of poor follow-up or poor adherence to physician recommendations
• Patient is planning to relocate outside the local area before the end of pregnancy such that delivery records will be unavailable
• Patient does not give consent to participate in this trial.