{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T21:08:11Z","timestamp":1792098491556,"version":"4.4.0"},"reference-count":50,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2023,12,5]],"date-time":"2023-12-05T00:00:00Z","timestamp":1701734400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["obgyn.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Acta Obstet Gynecol Scand"],"published-print":{"date-parts":[[2024,3]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Introduction<\/jats:title><jats:p>There are many risk factors for obstetric anal sphincter injury (OASIS) and the interaction between these risk factors is complex and understudied. The many observational studies that have shown a reduction of OASIS rates after implementation of perineal support have short follow\u2010up time. We aimed to study the effect of integration of active perineal support and lateral episiotomy on OASIS rates over a 15\u2010year period and to study interactions between risk factors known before delivery.<\/jats:p><\/jats:sec><jats:sec><jats:title>Material and methods<\/jats:title><jats:p>We performed a historical cohort study over the periods 1999\u20132006 and 2007\u20132021 at Stavanger University Hospital, Norway. The main outcome was OASIS rates. Women without a previous cesarean section and a live singleton fetus in cephalic presentation at term were eligible. The department implemented in 2007 the Finnish concept of active perineal protection, which includes support of perineum, control of fetal expulsion, good communication with the mother and observation of perineal stretching. The practice of mediolateral episiotomy was replaced with lateral episiotomy when indicated. We analyzed the OASIS rates in groups with and without episiotomy stratified for delivery mode, fetal position at delivery and for parity, and adjusted for possible confounders (maternal age, gestational age, oxytocin augmentation and epidural analgesia).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We observed a long\u2010lasting reduction in OASIS rates from 4.9% to 1.9% and an increase in episiotomy rates from 14.4% to 21.8%. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with instrumental vaginal deliveries and occiput anterior (OA) position; 3.4% vs 10.1% (OR 0.31; 95% CI: 0.24\u20130.40) and 6.1 vs 13.9% (OR 0.40; 95% CI: 0.19\u20130.82) in women with occiput posterior (OP) position. Lateral episiotomy was also associated with lower OASIS rates in nulliparous women with spontaneous deliveries and OA position; 2.1% vs 3.2% (OR 0.62; 95% CI: 0.49\u20130.80). The possible confounders had little confounding effects on the risk of OASIS in groups with and without episiotomy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>We observed a long\u2010lasting reduction in OASIS rates after implementation of preventive procedures. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with an instrumental delivery. Special attention should be paid to deliveries with persistent OP position.<\/jats:p><\/jats:sec>","DOI":"10.1111\/aogs.14742","type":"journal-article","created":{"date-parts":[[2023,12,6]],"date-time":"2023-12-06T06:58:35Z","timestamp":1701845915000},"page":"488-497","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Prevention of obstetric anal sphincter injuries with perineal support and lateral episiotomy: A historical cohort study"],"prefix":"10.1111","volume":"103","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3162-9595","authenticated-orcid":false,"given":"Torbj\u00f8rn M.","family":"Eggeb\u00f8","sequence":"first","affiliation":[{"name":"Department of Clinical and Molecular Medicine Norwegian University of Science and Technology  Trondheim Norway"},{"name":"Department of Obstetrics and Gynecology Stavanger University Hospital  Stavanger Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Astrid Betten","family":"Rygh","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Stavanger University Hospital  Stavanger Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Phillip","family":"von Brandis","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology Stavanger University Hospital  Stavanger Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9875-4991","authenticated-orcid":false,"given":"Finn Egil","family":"Skjeldestad","sequence":"additional","affiliation":[{"name":"Research Group Epidemiology of Chronic Diseases, Institute of Community Medicine UiT the Arctic University of Norway  Troms\u00f8 Norway"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2023,12,5]]},"reference":[{"key":"e_1_2_13_2_1","doi-asserted-by":"publisher","DOI":"10.3109\/00016349.2010.512073"},{"key":"e_1_2_13_3_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2016-014183"},{"key":"e_1_2_13_4_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0b013e3181e2f50b"},{"key":"e_1_2_13_5_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2013-004592"},{"key":"e_1_2_13_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.srhc.2019.100460"},{"key":"e_1_2_13_7_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.midw.2018.04.012"},{"key":"e_1_2_13_8_1","doi-asserted-by":"publisher","DOI":"10.1080\/01443610802665090"},{"key":"e_1_2_13_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejogrb.2009.04.033"},{"key":"e_1_2_13_10_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0b013e3181eda77a"},{"key":"e_1_2_13_11_1","doi-asserted-by":"publisher","DOI":"10.1097\/AOG.0b013e31816c4402"},{"key":"e_1_2_13_12_1","doi-asserted-by":"publisher","DOI":"10.1111\/1471-0528.12274"},{"key":"e_1_2_13_13_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2012-001649"},{"key":"e_1_2_13_14_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2008.01960.x"},{"key":"e_1_2_13_15_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00192-012-1960-3"},{"key":"e_1_2_13_16_1","doi-asserted-by":"publisher","DOI":"10.1136\/bmjopen-2013-003216"},{"key":"e_1_2_13_17_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1471-0528.2005.00835.x"},{"key":"e_1_2_13_18_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0107053"},{"key":"e_1_2_13_19_1","article-title":"Selective versus routine use of episiotomy for vaginal birth","volume":"2","author":"Jiang H","year":"2017","journal-title":"Cochrane Database Syst Rev"},{"key":"e_1_2_13_20_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.0730-7659.2006.00088.x"},{"key":"e_1_2_13_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejogrb.2019.07.005"},{"key":"e_1_2_13_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0889-8545(05)70077-2"},{"key":"e_1_2_13_23_1","unstructured":"World Health Organization.Intrapartum Care for a Positive Childbirth Experience.2020. 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