Norman, Jane E.Norrie, JohnMaclennan, GraemeCooper, DavidWhyte, SoniaBurley, Sarah CunninghamSmith, Joel B.E.Shennan, AndrewRobson, Stephen C.Thornton, StevenKilby, Mark D.Marlow, NeilStock, Sarah J.Bennett, Philip R.Denton, Jane2019-05-282019-05-282019-02Norman, J E, Norrie, J, Maclennan, G, Cooper, D, Whyte, S, Burley, S C, Smith, J B E, Shennan, A, Robson, S C, Thornton, S, Kilby, M D, Marlow, N, Stock, S J, Bennett, P R & Denton, J 2019, 'Open randomised trial of the (Arabin) pessary to prevent preterm birth in twin pregnancy with health economics and acceptability : STOPPIT-2-a study protocol', BMJ Open, vol. 8, no. 12, e026430. https://doi.org/10.1136/bmjopen-2018-0264302044-6055Mendeley: da9b2207-9ccc-3bdd-91de-e04236c66527ORCID: /0000-0002-1039-5646/work/98038521http://hdl.handle.net/2164/12319Contributors All authors contributed to the intellectual content of this protocol. JEN and SW wrote the first draft, with the exception of the statistical analysis plan (which was written by DC, with input from GM and JN), health economics (written by JS) and the qualitative research (written by SCB). All authors contributed to further drafting and approved the final version. Funding This study was funded by the NIHR Health Technology Assessment Programme (project number 13/04/22). Disclaimer Department of Health and Social Care disclaimer. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care Competing interests JEN is a member of the HTA Maternal, Neonatal and Child health prioritisation panel. She has performed consultancy for the pharma companies LifeArc and Dilafor outside the scope of this work. ST provides commercial consultancy advice and is a Trustee or advisor for funding organisations. AS is on the HTA commissioning board and has received funding from Hologic (paid to institution) for preterm prediction studies (outside the scope of this work.) Patient consent Not required. Ethics approval STOPPIT-2 was approved by the South East of Scotland Research Ethics Committee 2 on 29th August 2014, reference number 14/SS/1031. Provenance and peer review Not commissioned; peer reviewed for ethical and funding approval prior to submission.378976engtwin pregnancyCERVICAL LENGTHWOMENMULTICENTERPREDICTIONRG Gynecology and obstetricsGeneral MedicineRGJournal article10.1136/bmjopen-2018-026430http://www.scopus.com/inward/record.url?scp=85058367420&partnerID=8YFLogxKhttp://www.mendeley.com/research/open-randomised-trial-arabin-pessary-prevent-preterm-birth-twin-pregnancy-health-economics-acceptabi812