{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T22:25:04Z","timestamp":1787091904654,"version":"build-2736575974"},"reference-count":37,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T00:00:00Z","timestamp":1784764800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T00:00:00Z","timestamp":1784764800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100020256","name":"Medisinske fakultet, Universitetet i Oslo","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100020256","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006095","name":"Helse S\u00f8r-\u00d8st RHF","doi-asserted-by":"publisher","award":["2799026"],"award-info":[{"award-number":["2799026"]}],"id":[{"id":"10.13039\/501100006095","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Ultrasound in Obstet &amp;amp; Gyne"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>The first aim was to describe longitudinal changes in levator hiatus area from 21\u2009weeks' gestation in the first pregnancy to 1 and 8\u2009years after first delivery, according to subsequent vaginal parity in women with vaginal delivery or Cesarean section (CS) at first delivery. The second aim was to assess the effect of subsequent vaginal delivery on levator hiatus area after first vaginal delivery.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>In this prospective cohort study with an 8\u2010year recall extension, 183 initially nulliparous women underwent three\u2010 and four\u2010dimensional transperineal ultrasound examination at 21\u2009weeks' gestation and 1 and 8\u2009years after first delivery. The levator hiatus area at rest, during maximum pelvic floor muscle contraction and during maximum Valsalva maneuver was assessed at each timepoint. Participants with multiple vaginal deliveries (vaginal multiparae), only one vaginal delivery (vaginal primiparae), CS for all deliveries and vaginal birth after CS were compared. The differences between study groups in levator hiatus area over time were assessed using a linear mixed model.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Overall, vaginal multiparae showed a statistically significant non\u2010linear increase in levator hiatus area from 21\u2009weeks' gestation to 8\u2009years after first delivery (\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&lt;\u20090.001). In contrast, participants who delivered exclusively by CS showed a decrease in levator hiatus area from 21\u2009weeks' gestation to the 8\u2010year follow\u2010up. Subsequent vaginal delivery after an initial vaginal delivery did not affect the levator hiatus area during Valsalva maneuver. At the 1\u2010year and 8\u2010year follow\u2010up after the first vaginal delivery, levator hiatus area at rest remained unchanged in vaginal multiparae but decreased in vaginal primiparae. At the 8\u2010year follow\u2010up, vaginal multiparae had a larger hiatus area during pelvic floor muscle contraction than did vaginal primiparae.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      In this study, the levator hiatus area was influenced by the mode of the first delivery and by subsequent vaginal deliveries. Overall, the levator hiatus area increased from 21\u2009weeks' gestation to 8\u2009years in participants with at least one vaginal delivery and decreased in those who delivered exclusively by CS. Subsequent vaginal delivery after a first did not seem to affect the levator hiatus area measured during Valsalva maneuver. \u00a9 2026 The Author(s).\n                      <jats:italic>Ultrasound in Obstetrics &amp; Gynecology<\/jats:italic>\n                      published by John Wiley &amp; Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/uog.70278","type":"journal-article","created":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T14:55:44Z","timestamp":1784818544000},"page":"276-283","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Levator hiatus area from 21\u2009weeks' gestation to 8\u2009years after first delivery according to vaginal parity: prospective cohort study with an 8\u2010year recall extension"],"prefix":"10.1002","volume":"68","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7413-8307","authenticated-orcid":false,"given":"F.","family":"Siafarikas","sequence":"first","affiliation":[{"name":"Faculty of Medicine, Division Akershus University Hospital University of Oslo  Oslo Norway"},{"name":"Department of Obstetrics and Gynecology Akershus University Hospital  L\u00f8renskog Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"\u0160altyt\u0117 Benth","sequence":"additional","affiliation":[{"name":"Institute of Clinical Medicine, Campus Ahus University of Oslo  Oslo Norway"},{"name":"Health Services Research Unit Akershus University Hospital  L\u00f8renskog Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"St\u00e6r\u2010Jensen","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Akershus University Hospital  L\u00f8renskog 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