The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study

Abstract Introduction Severe perineal injuries at childbirth affect women's postnatal health, including future childbirths. First births with vacuum extraction carry an increased risk of obstetric anal sphincter injuries (OASIS). Lateral or mediolateral episiotomy at vacuum extraction may decre...

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Main Authors: Sophia Brismar Wendel, Can Liu, Olof Stephansson
Format: Article
Language:English
Published: Wiley 2023-03-01
Series:Acta Obstetricia et Gynecologica Scandinavica
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Online Access:https://doi.org/10.1111/aogs.14513
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author Sophia Brismar Wendel
Can Liu
Olof Stephansson
author_facet Sophia Brismar Wendel
Can Liu
Olof Stephansson
author_sort Sophia Brismar Wendel
collection DOAJ
description Abstract Introduction Severe perineal injuries at childbirth affect women's postnatal health, including future childbirths. First births with vacuum extraction carry an increased risk of obstetric anal sphincter injuries (OASIS). Lateral or mediolateral episiotomy at vacuum extraction may decrease the risk of OASIS. Our aim was to assess whether lateral or mediolateral episiotomy, or OASIS, at vacuum extraction in nulliparous women is associated with prelabor cesarean delivery in the subsequent childbirth. Material and methods This is a nationwide observational study using data from the Swedish Medical Birth Register, including women having a first birth with vacuum extraction and a second birth in 2000–2014. Both births were live, single, cephalic, ≥34 gestational weeks without malformations. The association between episiotomy or OASIS in the first birth and prelabor cesarean delivery in the second birth was examined using univariate and multivariate logistic regression with inverse probability of treatment weighting, and interaction analysis. Main outcome measure was prelabor cesarean delivery in the second birth. Results In total, 44 656 women with vacuum extraction at their first birth were included. The rate of prelabor cesarean delivery in the second birth was 5.9% (824 of 13 950) in women with episiotomy, compared with 6.0% (1830 of 30 706) in women without episiotomy. Thus, women with episiotomy did not have an increased risk of prelabor cesarean delivery (adjusted odds ratio [aOR] 1.00, 95% confidence interval [95% CI] 0.83–1.20) compared with women without episiotomy. For comparison, the rate of prelabor cesarean delivery in the second birth was 20.6% (1275 of 6176) in women with OASIS, compared with 3.6% (1379 of 38 480) in women without OASIS (aOR 6.57, 95% CI 5.97–7.23). There was no interaction between episiotomy and OASIS. Conclusions Lateral or mediolateral episiotomy at vacuum extraction in nulliparous women did not increase the risk of prelabor cesarean delivery in the subsequent childbirth. OASIS increased the odds of prelabor cesarean delivery more than sixfold.
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spelling doaj-art-d9794bdeeef24cfd9fd4c1d8ce6ca5902025-08-20T03:22:12ZengWileyActa Obstetricia et Gynecologica Scandinavica0001-63491600-04122023-03-01102337838810.1111/aogs.14513The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational studySophia Brismar Wendel0Can Liu1Olof Stephansson2Department of Clinical Sciences Karolinska Institutet, Danderyd Hospital Stockholm SwedenClinical Epidemiology Division, Department of Medicine Karolinska Institutet Stockholm SwedenClinical Epidemiology Division, Department of Medicine Karolinska Institutet Stockholm SwedenAbstract Introduction Severe perineal injuries at childbirth affect women's postnatal health, including future childbirths. First births with vacuum extraction carry an increased risk of obstetric anal sphincter injuries (OASIS). Lateral or mediolateral episiotomy at vacuum extraction may decrease the risk of OASIS. Our aim was to assess whether lateral or mediolateral episiotomy, or OASIS, at vacuum extraction in nulliparous women is associated with prelabor cesarean delivery in the subsequent childbirth. Material and methods This is a nationwide observational study using data from the Swedish Medical Birth Register, including women having a first birth with vacuum extraction and a second birth in 2000–2014. Both births were live, single, cephalic, ≥34 gestational weeks without malformations. The association between episiotomy or OASIS in the first birth and prelabor cesarean delivery in the second birth was examined using univariate and multivariate logistic regression with inverse probability of treatment weighting, and interaction analysis. Main outcome measure was prelabor cesarean delivery in the second birth. Results In total, 44 656 women with vacuum extraction at their first birth were included. The rate of prelabor cesarean delivery in the second birth was 5.9% (824 of 13 950) in women with episiotomy, compared with 6.0% (1830 of 30 706) in women without episiotomy. Thus, women with episiotomy did not have an increased risk of prelabor cesarean delivery (adjusted odds ratio [aOR] 1.00, 95% confidence interval [95% CI] 0.83–1.20) compared with women without episiotomy. For comparison, the rate of prelabor cesarean delivery in the second birth was 20.6% (1275 of 6176) in women with OASIS, compared with 3.6% (1379 of 38 480) in women without OASIS (aOR 6.57, 95% CI 5.97–7.23). There was no interaction between episiotomy and OASIS. Conclusions Lateral or mediolateral episiotomy at vacuum extraction in nulliparous women did not increase the risk of prelabor cesarean delivery in the subsequent childbirth. OASIS increased the odds of prelabor cesarean delivery more than sixfold.https://doi.org/10.1111/aogs.14513cesarean sectionepisiotomynulliparousobstetric anal sphincter injurysubsequent deliveryvacuum extraction
spellingShingle Sophia Brismar Wendel
Can Liu
Olof Stephansson
The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
Acta Obstetricia et Gynecologica Scandinavica
cesarean section
episiotomy
nulliparous
obstetric anal sphincter injury
subsequent delivery
vacuum extraction
title The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
title_full The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
title_fullStr The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
title_full_unstemmed The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
title_short The association between episiotomy or OASIS at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery: A nationwide observational study
title_sort association between episiotomy or oasis at vacuum extraction in nulliparous women and subsequent prelabor cesarean delivery a nationwide observational study
topic cesarean section
episiotomy
nulliparous
obstetric anal sphincter injury
subsequent delivery
vacuum extraction
url https://doi.org/10.1111/aogs.14513
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