Evidence map›Paper›PMID 42032840›Full record

ArticleThe Australian & New Zealand journal of obstetrics & gynaecology2026

Episiotomy and Obstetric Anal Sphincter Injury Among Unassisted Vaginal Births: A Retrospective Cohort Study.

Meghan G Hill, Aimee Humphries, Jessica Wilson, Amanda D Harvey, Robin Cronin, John M D Thompson, Lynn C Sadler

Abstract read
In one paragraph

Article in The Australian & New Zealand journal of obstetrics & gynaecology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Meghan G HillDepartment of Obstetrics, Gynaecology and Reproductive Sciences, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0002-4096-5339
Aimee HumphriesTe Whatu Ora | Te Toka Tumai Auckland, Auckland, New Zealand.
Jessica WilsonDepartment of Obstetrics, Gynaecology and Reproductive Sciences, University of Auckland, Auckland, New Zealand.
Amanda D HarveyDepartment of Obstetrics, Gynaecology and Reproductive Sciences, University of Auckland, Auckland, New Zealand.
Robin CroninDepartment of Obstetrics, Gynaecology and Reproductive Sciences, University of Auckland, Auckland, New Zealand.
John M D ThompsonDepartment of Obstetrics, Gynaecology and Reproductive Sciences, University of Auckland, Auckland, New Zealand.ORCID https://orcid.org/0000-0001-6944-381X
Lynn C SadlerTe Whatu Ora | Te Toka Tumai Auckland, Auckland, New Zealand.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundMediolateral episiotomy (MLE) is a common procedure. Whether it modifies the risk of obstetric anal sphincter injury (OASI) in nulliparous and parous people is unclear.

aimsWe performed a retrospective cohort study to assess if MLE was associated with decreased OASI. MATERIALS AND

methodsA retrospective cohort study including all unassisted vaginal births from 36 weeks' from 2008 to 2021 was assembled. Analysis was separated for first and subsequent vaginal births, adjusting for maternal height, body mass index (BMI), ethnicity, prior caesarean birth (if no previous vaginal birth) or pre-delivery parity (if there was a previous vaginal birth), smoking status, augmentation of labour, induction of labour, length of second stage, caregiver type, socioeconomic deprivation quintile, gestational age, baby head circumference, baby birthweight and use of epidural using Generalized Linear Models.

resultsThere were 49 363 unassisted vaginal births. Of these, 20 201 were first vaginal births (19 082 nullipara and 1119 with one prior caesarean birth), 27 825 subsequent vaginal births, and 1337 unknown vaginal birth status. Episiotomy and OASI were recorded in 28.6% and 3.6% of first and 9.1% and 0.8% of subsequent vaginal births, respectively. Among first vaginal births, there was no association between episiotomy and OASI in univariable (RR 1.00 (0.86, 1.17)) or multivariable analysis (RR 0.91 (0.77, 1.09)). Among subsequent vaginal births, episiotomy was associated with increased odds of OASI in univariable (RR 2.21 (1.57, 3.13)) and multivariable analysis (RR 1.55 (1.08, 2.22)).

conclusionOur findings do not support the use of MLE for first births and suggest harm for subsequent births.

Indexed as

Anal CanalDelivery, ObstetricEpisiotomyObstetric Labor ComplicationsAdultFemaleHumansParityPregnancyRetrospective StudiesRisk FactorsYoung Adultdeliveryepisiotomyobstetricobstetric surgical proceduresparityperineum

Identifiers

PMID42032840
PMCPMC13109605

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