The acceptability of emergency cervical cerclage within a randomised controlled trial for cervical dilatation with exposed membranes at 16-27+6 weeks gestation: Findings from a qualitative process evaluation of the C-STICH2 pilot trial

Objective: C-STICH2 is a randomised controlled trial of emergency cervical cerclage (ECC) vs routine care in women who present in pregnancy with premature cervical dilatation and exposed unruptured fetal membranes. Within the proposed trial an internal pilot was performed with an embedded qualitative process evaluation (QPE) to explore the feasibility of recruitment. The QPE aimed to collect and analyse data exploring the expe-riences of health care professionals (HCPs) involved in recruitment, and women approached about the trial.Methods: Semi-structured interviews (telephone or face-to-face) were held with eligible participants who had consented to participate in the QPE. Interviews were audio-recorded, transcribed, and analysed to identify main themes. Interview transcripts were analysed using qualitative thematic analysis (QTA).Results: 11 women and 23 HCPs were interviewed. Three super-ordinate themes of Fluidity of Equipoise, A Complex Obstetric History, and the Influence of Gestation were identified. Within these, the five main themes which influenced trial participation were: 1) Complex decision-making processes; 2) Predicting outcomes; 3) The importance of terminology and initial RCT approach; 4) Women's understanding of the need for research in this area; 5) Changes in practice which are trial influenced.Conclusions: For both HCPs and women and their families, there was a conflation of the potential risks and outcomes of ECC with those of elective cerclage and the complexity around ECC placement was not always well understood by those with less experience and understanding of the intervention. Decision making was shown to be complex and multi-factorial for both HCPs and women. For complex trials in rare conditions with treatment uncertainty, clinical equipoise is likely to be fluid and influenced by multiple factors.