RESEARCH Open Access Women’s experiences of receiving information about and consenting or declining to participate in a randomized controlled trial involving episiotomy in vacuum-assisted delivery: a qualitative study Jenny Ericson 1,2,3* , Cecilia Anagrius 4 , Agnes Rygaard 4 , Lisa Guntram 5 , Sophia Brismar Wendel 6 and Susanne Hesselman 2,4,7 Abstract Background: Information about and invitation to participate in a clinical trial involving an intervention during childbirth may cause fear or worry in pregnant women. The aim of this study was to describe nulliparous women’s experiences of receiving an invitation to participate in a randomized controlled trial (RCT) of lateral episiotomy versus no episiotomy in vacuum-assisted delivery (EVA trial). Methods: This qualitative study was nested in the ongoing EVA trial. Data were collected through semistructured telephone interviews with 23 women regarding their experiences of the information and invitation to participate in the EVA trial. Interviews were audio-recorded and transcribed verbatim. A qualitative content analysis was used to analyse the interview contents. Results: Three main experience categories were identified among the participants. “Timing of trial information and understanding” revealed that women preferred to obtain information about the trial early on during pregnancy. “Reasons to consent to or decline participation in the trial” encompassed a variety of reasons for women to consent, such as goodwill for science or personal benefits, or to decline, such as not wanting to be randomized or fear of increased risk of having a vacuum-assisted delivery. “Thoughts evoked regarding childbirth” were diverse, ranging from not being affected at all to having increased anxiety. Conclusions: The women’s experience of receiving an invitation to participate in an RCT of episiotomy in vacuum- assisted delivery varied widely, from immediately giving consent without further worries to increased anxiety or declining participation. Early and personal information with time for reflection was considered most satisfactory. © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. * Correspondence: jenny.ericson@regiondalarna.se 1 School of Education, Health and Social Studies, Dalarna University, Falun, Sweden 2 Center for Clinical Research Dalarna, Uppsala University, Falun, Sweden Full list of author information is available at the end of the article Ericson et al. Trials (2021) 22:658 https://doi.org/10.1186/s13063-021-05624-8