Background: Preterm birth is associated with significant mortality and morbidity for mothers and babies. Women are identified as high risk for preterm birth based on either previous medical/pregnancy history or on ultrasound assessment of the cervix. Women identified as high risk can be offered a cervical cerclage (a purse string stitch) around the cervix (neck of the womb) to reduce the risk of preterm birth. In women who have a cervical cerclage, the procedure can be performed using either a monofilament (single-stranded) or braided (woven) suture material. Both suture materials are routinely used for cervical cerclage and there is uncertainty as to which is superior. Methods: A multicentre, open, randomised controlled superiority trial of 2050 women presenting at obstetric units, deemed to be at risk of preterm birth and already scheduled to have a cervical cerclage as part of their standard care. Inclusion criteria include singleton pregnancies and an indication for cervical cerclage for either a history of three or more previous mid-trimester losses or premature births (≤ 28 weeks), insertion of cervical sutures in previous pregnancies, a history of mid trimester loss or premature birth with a (current) shortened (≤ 25 mm) cervix, or women whom clinicians deem to be at risk of preterm birth either by history or the results of an ultrasound scan. Exclusion criteria include women who have taken part in C-STICH previously, are aged less than 18 years old at the time of presentation, require a rescue cerclage, and are unwilling or unable to give informed consent and in whom a cerclage will be placed by any route other than vaginally (e.g. via an abdominal route). Following informed consent, women are randomised on a 1:1 basis to either monofilament or braided suture, by minimisation. The primary outcome is pregnancy loss (miscarriage and perinatal mortality, including any stillbirth or neonatal death in the first week of life), and secondary outcomes include the core outcome set for preterm birth trials. Discussion: Optimising established interventions to prevent preterm birth is important in reducing perinatal mortality rates. Trial registration: ISRCTN 15373349. Registered before recruitment on 03 December 2014 prior to first recruit.
Bibliographical noteFunding Information:
This study is funded by the National Institute for Health Research (NIHR) (project reference 13/04/107)/ HTA. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. The funder has not been involved in the design, analysis, and interpretation of data, but retains oversight regarding progress and completion timelines.
The success of the study depends entirely on the wholehearted collaboration of a large number of clinicians, Nurses / Midwifes, and others. For this reason, chief credit for the main results will be given not to the committees or central organisers but to all those who have collaborated in the study. We wish to thank all principal investigators and researchers at all 75 of our sites and the women who agreed to participate in the study. VHM has led the authorship of the protocol paper and worked as the research fellow for the trial providing support to all sites, academic oversight, and delivery. FIB performed the pilot study and developed the initial protocol and funding. CH and LM are the statisticians for the trial and have oversight of the trial design, reporting of results. AE is the lead advisor regarding the collection for the neonatal outcomes. JG has led the microbiological sub study and provided oversight for this. JN, CL, NS, and AS were co-applicants on the funding grant, have provided academic input into the trial design, and have led recruitment at lead sites. MH is the trial manager for the trial and has provided oversight and management of the trial. PB and KM have provided academic and methodological support for the trial from BCTU. PTH is the Chief Investigator for the trial and has conceived the study and led the team and protocol development. All authors have read and approved the manuscript. This study is funded by the National Institute for Health Research (NIHR) (project reference 13/04/107)/ HTA. The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. The funder has not been involved in the design, analysis, and interpretation of data, but retains oversight regarding progress and completion timelines. Requests for data generated during this study will be considered by BCTU. Data will typically be available within 6 months after the primary publication. Only scientifically sound proposals from appropriately qualified Research Groups will be considered for data sharing. The request will be reviewed by the BCTU Data Sharing Committee in discussion with the Chief Investigator and where appropriate (or in absence of the Chief Investigator) any of the following: the Trial Sponsor, the relevant Trial Management Group (TMG), and independent Trial Steering Committee (TSC). A formal Data Sharing Agreement (DSA) may be required between respective organisations once release of the data is approved and before data can be released. Data will be fully de-identified (anonymised) unless the DSA covers transfer of patient identifiable information. Any data transfer will use a secure and encrypted method.
© 2021, The Author(s).
- Cervical cerclage
- Obstetrics and gynaecology
- Preterm birth
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Pharmacology (medical)