{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,11]],"date-time":"2026-07-11T02:03:38Z","timestamp":1783735418321,"version":"3.55.0"},"reference-count":50,"publisher":"BMJ","issue":"3","funder":[{"DOI":"10.13039\/501100004359","name":"Vetenskapsr\u00e5det","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100004359","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2018,12,7]]},"published-print":{"date-parts":[[2019,3]]},"abstract":"<jats:sec>\n                  <jats:title>Introduction<\/jats:title>\n                  <jats:p>Obstetric anal sphincter injury (OASIS) occurs in 5%\u20137% of normal deliveries and increases with vacuum extraction (VE) to 12%\u201314% in nulliparous women in Sweden. Lateral\/mediolateral episiotomy may reduce the prevalence of OASIS at VE in nulliparous women. The current use of episiotomy is restrictive. The protective effect and consequences are uncertain. This trial will investigate if lateral episiotomy can reduce the prevalence of OASIS and assess short-term and long-term effects.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods and analysis<\/jats:title>\n                  <jats:p>This is a multicentre randomised controlled trial of lateral episiotomy versus no episiotomy in nulliparous women with a singleton, live fetus, after gestational week 34+0 with indication for VE. A lateral episiotomy of 4\u2009cm is cut at crowning, 1\u20133\u2009cm from the midline, at a 60\u00b0 angle. The primary outcome is OASIS by clinical diagnosis analysed according to intention to treat. To demonstrate a 50% reduction in OASIS prevalence (from 12.4% to 6.2%), 710 women will be randomised at a 1:1 ratio. Secondary outcomes are pain, blood loss, other perineal injuries, perineal complications, Apgar score, cord pH and neonatal complications. Web-based questionnaires at baseline, 2\u2009months, 1 and 5\u2009years will be used to assess pain, incontinence, prolapse, sexual function, quality of life and childbirth experience. A subset of women will receive follow-up by pelvic floor sonography and pelvic examination. Mode of delivery and recurrence of OASIS\/episiotomy in subsequent pregnancies will be assessed at 5 and 10 years using register data.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Ethics and dissemination<\/jats:title>\n                  <jats:p>The trial is open for enrolment. The trial has received ethical approval from the Regional Ethical Review Board of Stockholm and full funding from the Swedish Research Council. Women are interested in participation. The predominant restrictive view on episiotomy may limit recruitment. Results are of global interest and will be disseminated in peer-reviewed journals and at international congresses.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Trial registration number<\/jats:title>\n                  <jats:p>\n                     <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" xlink:href=\"NCT02643108\" ext-link-type=\"clintrialgov\" specific-use=\"clinicaltrial pre-results\">NCT02643108<\/jats:ext-link>; Pre-results.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/bmjopen-2018-025050","type":"journal-article","created":{"date-parts":[[2019,3,14]],"date-time":"2019-03-14T06:05:31Z","timestamp":1552543531000},"page":"e025050","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":24,"title":["Lateral episiotomy versus no episiotomy to reduce obstetric anal sphincter injury in vacuum-assisted delivery in nulliparous women: study protocol on a randomised controlled trial"],"prefix":"10.1136","volume":"9","clinical-trial-number":[{"clinical-trial-number":"nct02643108","registry":"10.18810\/clinical-trials-gov","type":"preResults"}],"author":[{"given":"Sandra","family":"Bergendahl","sequence":"first","affiliation":[{"name":"Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Victoria","family":"Ankarcrona","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c5sa","family":"Leijonhufvud","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences Lund\/Clinical Science Helsingborg, Lunds Universitet, Lund, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susanne","family":"Hesselman","sequence":"additional","affiliation":[{"name":"Department of Women\u2019s and Children\u2019s Health, Centre for Clinical Research Dalarna, Falu Hospital, Uppsala Universitet, Uppsala, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sofie","family":"Karlstr\u00f6m","sequence":"additional","affiliation":[{"name":"Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helena","family":"Kopp Kallner","sequence":"additional","affiliation":[{"name":"Department of Women\u2019s and Children\u2019s Health, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9401-8062","authenticated-orcid":false,"given":"Sophia","family":"Brismar Wendel","sequence":"additional","affiliation":[{"name":"Department of Clinical Sciences, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2019,3,13]]},"reference":[{"key":"2025101815071384000_9.3.e025050.1","doi-asserted-by":"publisher","DOI":"10.3109\/00016340903576004"},{"key":"2025101815071384000_9.3.e025050.2","unstructured":"Annual report 2016, Swedish Pregnancy Register (in Swedish) [Internet]. 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