| 1. |
- Bergendahl, Sandra, et al.
(author)
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Lateral episiotomy or no episiotomy in vacuum assisted delivery in nulliparous women (EVA) : multicentre, open label, randomised controlled trial
- 2024
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In: BMJ (Clinical research ed.). - : BMJ Publishing Group Ltd. - 1756-1833. ; 385
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To assess the effect of lateral episiotomy, compared with no episiotomy, on obstetric anal sphincter injury in nulliparous women requiring vacuum extraction.DESIGN: A multicentre, open label, randomised controlled trial.SETTING: Eight hospitals in Sweden, 2017-23.PARTICIPANTS: 717 nulliparous women with a single live fetus of 34 gestational weeks or more, requiring vacuum extraction were randomly assigned (1:1) to lateral episiotomy or no episiotomy using sealed opaque envelopes. Randomisation was stratified by study site.INTERVENTION: A standardised lateral episiotomy was performed during the vacuum extraction, at crowning of the fetal head, starting 1-3 cm from the posterior fourchette, at a 60° (45-80°) angle from the midline, and 4 cm (3-5 cm) long. The comparison was no episiotomy unless considered indispensable.MAIN OUTCOME MEASURES: The primary outcome of the episiotomy in vacuum assisted delivery (EVA) trial was obstetric anal sphincter injury, clinically diagnosed by combined visual inspection and digital rectal and vaginal examination. The primary analysis used a modified intention-to-treat population that included all consenting women with attempted or successful vacuum extraction. As a result of an interim analysis at significance level P<0.01, the primary endpoint was tested at 4% significance level with accompanying 96% confidence interval (CI).RESULTS: From 1 July 2017 to 15 February 2023, 717 women were randomly assigned: 354 (49%) to lateral episiotomy and 363 (51%) to no episiotomy. Before vacuum extraction attempt, one woman withdrew consent and 14 had a spontaneous birth, leaving 702 for the primary analysis. In the intervention group, 21 (6%) of 344 women sustained obstetric anal sphincter injury, compared with 47 (13%) of 358 women in the comparison group (P=0.002). The risk difference was -7.0% (96% CI -11.7% to -2.5%). The risk ratio adjusted for site was 0.47 (96% CI 0.23 to 0.97) and unadjusted risk ratio was 0.46 (0.28 to 0.78). No significant differences were noted between groups in postpartum pain, blood loss, neonatal outcomes, or total adverse events, but the intervention group had more wound infections and dehiscence.CONCLUSIONS: Lateral episiotomy can be recommended for nulliparous women requiring vacuum extraction to significantly reduce the risk of obstetric anal sphincter injury.TRIAL REGISTRATION: ClinicalTrials.gov NCT02643108.
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| 2. |
- Bergendahl, Sandra, et al.
(author)
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Lateral episiotomy versus no episiotomy to reduce obstetric anal sphincter injury in vacuum-assisted delivery in nulliparous women : Study protocol on a randomised controlled trial
- 2019
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In: BMJ Open. - : BMJ. - 2044-6055. ; 9:3
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Journal article (peer-reviewed)abstract
- Introduction Obstetric anal sphincter injury (OASIS) occurs in 5%-7% of normal deliveries and increases with vacuum extraction (VE) to 12%-14% in nulliparous women in Sweden. Lateral/mediolateral episiotomy may reduce the prevalence of OASIS at VE in nulliparous women. The current use of episiotomy is restrictive. The protective effect and consequences are uncertain. This trial will investigate if lateral episiotomy can reduce the prevalence of OASIS and assess short-term and long-term effects. Methods and analysis This is a multicentre randomised controlled trial of lateral episiotomy versus no episiotomy in nulliparous women with a singleton, live fetus, after gestational week 34+0 with indication for VE. A lateral episiotomy of 4 cm is cut at crowning, 1-3 cm from the midline, at a 60° angle. The primary outcome is OASIS by clinical diagnosis analysed according to intention to treat. To demonstrate a 50% reduction in OASIS prevalence (from 12.4% to 6.2%), 710 women will be randomised at a 1:1 ratio. Secondary outcomes are pain, blood loss, other perineal injuries, perineal complications, Apgar score, cord pH and neonatal complications. Web-based questionnaires at baseline, 2 months, 1 and 5 years will be used to assess pain, incontinence, prolapse, sexual function, quality of life and childbirth experience. A subset of women will receive follow-up by pelvic floor sonography and pelvic examination. Mode of delivery and recurrence of OASIS/episiotomy in subsequent pregnancies will be assessed at 5 and 10 years using register data. Ethics and dissemination The trial is open for enrolment. The trial has received ethical approval from the Regional Ethical Review Board of Stockholm and full funding from the Swedish Research Council. Women are interested in participation. The predominant restrictive view on episiotomy may limit recruitment. Results are of global interest and will be disseminated in peer-reviewed journals and at international congresses.
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| 3. |
- Bergendahl, Sandra
(author)
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Vacuum extraction and pelvic floor injury : a randomized controlled trial and cohort studies
- 2024
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Doctoral thesis (other academic/artistic)abstract
- BACKGROUND AND AIMS: Pelvic floor dysfunction (PFD) affects many women, especially after complicated childbirth. The impact of a prolonged second stage on PFD is not clear, while the effects of operative vaginal birth (OVB) and obstetric anal sphincter injury (OASI) are better known, especially concerning the risk of anal incontinence (AI). Vacuum extraction (VE) and primiparity are the major risk factors of OASI. Observational studies report that OASI in VE in nulliparous women decreases if an episiotomy is performed, but this has not been confirmed in a randomized controlled trial (RCT). The aim of this thesis was to investigate factors that could improve second stage management, particularly in VE, to decrease the risk of OASI and future PFD. First, we aimed to identify risk factors for OASI in VE. Second, we aimed to explore effects of a prolonged second stage on PFD, and finally, we aimed to investigate if a lateral episiotomy, compared with no episiotomy, reduces the risk of OASI in VE in nulliparous women. METHODS AND MAIN RESULTS: Study I is a retrospective cohort study with one-year medical records data from Danderyd Hospital. All primiparous women with a live, singleton fetus ≥34 gestational weeks, delivered by VE during 2013 were included (n=323). Primary outcome was OASI and exposure was operator category (obstetrician, gynecologist, and resident) with obstetrician as reference. OASI occurred in 57 (17.6%) women. Fifteen (11.5%) OASI occurred in VE performed by obstetricians, 10 (13.5%) by gynecologists (aOR 1.84, 95% CI 0.72-4.70), and 32 (26.9%) by residents (aOR 5.13, 95% CI 2.20-11.95). Study II and III are questionnaire and cohort studies including primiparous women with a live, single fetus in cephalic presentation ≥37 gestational weeks and second stage duration ≥3 h in the Stockholm Region during one year (2019, n=1302). Data were retrieved from electronic medical records (EMR). The oneyear follow-up questionnaire from the Swedish Perineal Laceration Register, including questions regarding symptoms of urinary incontinence (UI), anal incontinence (AI), and pelvic organ prolapse (POP) were distributed one to two years after delivery. In Study II, primary outcome was AI defined as Wexner score ≥2. Main exposure was mode of delivery with cesarean section (CS) as reference. Secondary exposures were degree of perineal injury and extended second stage duration. We found that the odds of AI were increased by VE (aOR 2.25, 95% CI 1.21-4.18) but not by spontaneous vaginal birth (SVB) (aOR 1.55, 95% CI 0.85-2.84). AI was also increased by OASI (aOR 2.03, 95% CI 1.17-3.52) and second-degree perineal injuries (aOR 1.36, 95% CI 1.03-1.81). OASI and VE combined inferred the highest odds (aOR 4.06, 95% CI 1.80-9.14) compared with CS. Extended duration of the prolonged second stage did not affect the risk of AI. In Study III, primary outcome was a composite of PFD including at least weekly symptoms of UI, AI, and POP. Exposure was intervention with VE or CS at 3-4 h or at 4-5 h respectively, compared with expectant management. The risk of PFD was increased after VE at 3-4 h (aRR 1.33, 95% CI 1.06-1.65) and 4-5 h (aRR 1.34, 95% CI 1.05-1.70), but remained unchanged after CS. The increased risk after VE was not mediated by OASI. Study IV is a multicenter RCT of lateral episiotomy compared with no episiotomy in nulliparous women with a live, single, fetus ≥34 gestational weeks, requiring VE during 2017-2023. The intervention was a lateral episiotomy. Primary outcome was OASI. The modified intention-to-treat (mITT) population included women with attempted or successful VE (n=702). In the intervention group, 21/344 (6.1%) women sustained OASI compared with 47/358 (13.1%) in the comparison group (p=0.002). The risk difference was -7.0% (96% CI -11.7% to - 2.5%). The unadjusted risk ratio was 0.46 (96% CI 0.28-0.78) and 0.47 (96% CI 0.23-0.97) adjusted for site. Number needed to treat was 14.3 to avoid one OASI. Wound infection and dehiscence were significantly increased in the intervention group, while all other outcomes were similar. CONCLUSION: In VE in nulliparous women, the risk of OASI increased when the operator was a resident, indicating a need for increased training and supervision. In a prolonged second stage, an extended duration did not increase the risk of AI or PFD. If a SVB seems likely, it is better to wait than to intervene with VE in order to avoid future PFD. If intervention is necessary, and several risk factors for OASI are present, CS could be preferable to reduce the risk of AI. In VE in nulliparous women, a lateral episiotomy significantly reduces the risk of OASI. However, the intervention may increase the risk of wound infection and dehiscence.
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