On Internal Hold

Through cervical length measurement in uncomplicated twin gestations, women with cervical length ≤ 25 mm will be approached for randomization to cerclage placement or expectant management with activity restriction and treatment of preterm labor

Pregnant women with twin gestations are screened for short cervix with transvaginal cervical length measurements as part of routine care at St. Mary's Health Center (SMHC) and Saint Louis University's (SLUCare) Physician Group. (Transvaginal cervical length measurement every 2 weeks from 16weeks/0days-23weeks/6days weeks, per hospital practice) Women pregnant with twin gestations at SMHC who meet study criteria will undergo transvaginal length screening between 16 and 24 weeks gestation. Those women with transvaginal cervical length measurements at or below 25 mm will be approached for study participation.

If a patient agrees to participate in the trial, they will be randomized in 1:1 fashion to cerclage vs. expectant management.

Participants found to have a vaginal infection by cultures performed at randomization will be treated with appropriate antibiotics per usual institutional practices

Cerclage arm:

- Macdonald cerclage placed in standard fashion: mersilene suture preferred for standardization

Expectant management arm:

- Patient is placed on activity restrictions: no heavy lifting, frequent reclining, and pelvic rest.

If a participant does not consent to participate in the trial, permission to collect their outcome information in an observational manner will be requested.

The neonatal medical record will be reviewed for outcome data on twins, weights, complications, neonatal intensive care unit (NICU) stay, to 28 day after discharge.

Inclusion Criteria:

• at least 14 years of age, but less than 55 yrs of age
• must be able to read and write English
• must be able to give informed consent.
• Twin pregnancy

Exclusion Criteria:

• Women with a serious physical or mental illness or condition that would substantially interfere with participation in the study
• membrane prolapse beyond the external cervical os,
• major fetal anomaly in either twins will be excluded from randomization.