{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T20:34:11Z","timestamp":1789850051541,"version":"4.0.1"},"reference-count":32,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2014,3,5]],"date-time":"2014-03-05T00:00:00Z","timestamp":1393977600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["BJOG"],"published-print":{"date-parts":[[2014,8]]},"abstract":"<jats:sec><jats:title>Objective<\/jats:title><jats:p>To establish the incidence of levator ani muscle (<jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content>) avulsion in primiparous women and to develop a clinically applicable risk prediction model.<\/jats:p><\/jats:sec><jats:sec><jats:title>Design<\/jats:title><jats:p>Observational longitudinal cohort study.<\/jats:p><\/jats:sec><jats:sec><jats:title>Setting<\/jats:title><jats:p>District General University Hospital, United Kingdom.<\/jats:p><\/jats:sec><jats:sec><jats:title>Sample<\/jats:title><jats:p>Nulliparous women at 36\u00a0weeks of gestation and 3\u00a0months postpartum.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Four\u2010dimensional transperineal ultrasound was performed during both visits. Tomographic ultrasound imaging at maximum contraction was used to diagnose no, minor or major <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion. A risk model was developed using multivariable ordinal logistic regression.<\/jats:p><\/jats:sec><jats:sec><jats:title>Main outcome measures<\/jats:title><jats:p>Incidence of <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion and its risk factors.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Of 269 women with no antenatal <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion 71% (<jats:italic>n<\/jats:italic>\u00a0=\u00a0191) returned postpartum. No <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion was found after caesarean section (<jats:italic>n<\/jats:italic>\u00a0=\u00a048). Following vaginal delivery the overall incidence of <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion was 21.0% (<jats:italic>n<\/jats:italic>\u00a0=\u00a030, 95% confidence interval [95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content>] 15.1\u201328.4). Minor and major <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion were diagnosed in 4.9% (<jats:italic>n<\/jats:italic>\u00a0=\u00a07, 95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content> 2.2\u20139.9) and 16.1% (<jats:italic>n<\/jats:italic>\u00a0=\u00a023, 95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content> 10.9\u201323.0), respectively. Risk factors were obstetric anal sphincter injuries (odds ratio [<jats:styled-content style=\"fixed-case\">OR<\/jats:styled-content>] 4.4, 95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content> 1.6\u201312.1), prolonged active second stage of labour per hour (<jats:styled-content style=\"fixed-case\">OR<\/jats:styled-content> 2.2, 95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content> 1.4\u20133.3) and forceps delivery (<jats:styled-content style=\"fixed-case\">OR<\/jats:styled-content> 6.6, 95% <jats:styled-content style=\"fixed-case\">CI<\/jats:styled-content> 2.5\u201317.2). A risk model and nomogram were developed to estimate a woman's individual risk: three risk factors combined revealed a 75% chance of <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Twenty\u2010one percent of women sustain <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion during their first vaginal delivery. Our risk model and nomogram are novel tools to estimate individual chances of <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion. We can now target postnatal women at risk of sustaining a <jats:styled-content style=\"fixed-case\">LAM<\/jats:styled-content> avulsion.<\/jats:p><\/jats:sec>","DOI":"10.1111\/1471-0528.12676","type":"journal-article","created":{"date-parts":[[2014,3,5]],"date-time":"2014-03-05T07:18:42Z","timestamp":1394003922000},"page":"1155-1163","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":89,"title":["Levator ani muscle avulsion during childbirth: a risk prediction model"],"prefix":"10.1111","volume":"121","author":[{"given":"K","family":"van Delft","sequence":"first","affiliation":[{"name":"Urogynaecology Unit Department of Obstetrics and Gynaecology Croydon University Hospital Croydon UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R","family":"Thakar","sequence":"additional","affiliation":[{"name":"Urogynaecology Unit Department of Obstetrics and Gynaecology Croydon University Hospital Croydon UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"AH","family":"Sultan","sequence":"additional","affiliation":[{"name":"Urogynaecology Unit Department of Obstetrics and Gynaecology Croydon University Hospital Croydon UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N","family":"Schwertner\u2010Tiepelmann","sequence":"additional","affiliation":[{"name":"Urogynaecology Unit Department of Obstetrics and Gynaecology Croydon University Hospital Croydon UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Kluivers","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynaecology (791) Radboud University Medical Centre Nijmegen the Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2014,3,5]]},"reference":[{"key":"e_1_2_7_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0002-9378(43)90528-9"},{"key":"e_1_2_7_3_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199312233292601"},{"key":"e_1_2_7_4_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2008.01751.x"},{"key":"e_1_2_7_5_1","doi-asserted-by":"publisher","DOI":"10.1097\/00006250-200301000-00012"},{"key":"e_1_2_7_6_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000178779.62181.01"},{"key":"e_1_2_7_7_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000194063.63206.1c"},{"key":"e_1_2_7_8_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0b013e3181a5ef23"},{"key":"e_1_2_7_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2009.03.028"},{"key":"e_1_2_7_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2009.11.038"},{"key":"e_1_2_7_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2010.02704.x"},{"key":"e_1_2_7_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.10132"},{"key":"e_1_2_7_13_1","doi-asserted-by":"publisher","DOI":"10.1097\/01.AOG.0000109207.22354.65"},{"key":"e_1_2_7_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.11080"},{"key":"e_1_2_7_15_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00192-009-0837-6"},{"key":"e_1_2_7_16_1","doi-asserted-by":"publisher","DOI":"10.3109\/01443615.2013.767787"},{"key":"e_1_2_7_17_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.1899"},{"key":"e_1_2_7_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.12426"},{"key":"e_1_2_7_19_1","doi-asserted-by":"publisher","DOI":"10.1002\/uog.3951"},{"key":"e_1_2_7_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00192-010-1329-4"},{"key":"e_1_2_7_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ajog.2012.12.006"},{"key":"e_1_2_7_22_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2006.00819.x"},{"key":"e_1_2_7_23_1","unstructured":"Noru\u0161isMJ.PASW Statistics 18.0 Advanced Statistical Procedures Companion.2010. 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