Lateral episiotomy protects primiparous but not multiparous women from obstetric anal sphincter rupture.
ABSTRACT To identify the risk factors for obstetric anal sphincter rupture (OASR).
Retrospective population-based register study.
A total of 514,741 women with singleton pregnancy and vaginal delivery between 1997 and 2007 in Finland.
Primiparous (n = 2,315) and multiparous women (n = 534) with OASR were compared with primiparous and multiparous women without OASR by using stepwise logistic regression analysis.
The OASR risk.
Episiotomy decreased the likelihood of OASR for the primiparous [odds ratio (OR) 0.83, 95% CI (confidence interval) 0.75-0.92], but not the multiparous women (OR 2.01, 95% CI 1.67-2.44). The strongest risk factors for OASR among the primiparous women were forceps delivery (OR 10.20, 95% CI 3.60-28.90), birth weight over 4,000 g (OR 4.66, 95% CI 3.86-5.63), vacuum assisted delivery (OR 3.88, 95% CI 3.25-4.63), occiput posterior presentation (OR 3.17, 95% CI 1.64-6.15), and prolonged active second stage of birth (OR 2.06, 95% CI 1.65-2.58). Episiotomy was associated with decreased risks for OASR in vacuum assisted deliveries (OR 0.70, 95% CI 0.57-0.85). Risk factors for OASR among the multiparous women included forceps delivery (OR 10.13, 95% CI 2.46-41.81), prolonged active second stage of the birth (OR 7.18, 95% CI 4.32-11.91), birth weight over 4,000 g (OR 5.84, 95% CI 3.40-10.02), and vacuum assisted delivery (OR 4.17, 95% CI 3.17-5.48).
The results support the restrictive use of episiotomy, since 909 episiotomies appear to be needed to prevent one OASR among primiparous women. Equivalent estimate in vacuum assisted deliveries among primiparous women was 66, favoring routine use of episiotomy in such cases.
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ABSTRACT: To determine rates and risk factors for third and fourth degree perineal tears (severe perineal trauma) in a Western Australian context. A retrospective hospital-based cohort study was performed using computerised data for 10,408 singleton vaginal deliveries from 28 weeks gestation. Women with severe perineal trauma were compared to those without. Logistic regression analysis, stratified by parity, was used to assess demographic and obstetric factors associated with perineal trauma. Severe perineal trauma incidence was 3% (338/10408), 5.4% (239/4405) for primiparas and 1.7% (99/5990) for multiparas (p<0.001). Adjusted risk factors associated with trauma and common across parity included Asian or Indian ethnicity, shoulder dystocia and assisted delivery. Epidural analgesia (OR 0.72, 95% CI 0.54-0.96), preterm birth (OR 0.40, 95% CI 0.23-0.72) and episiotomy (OR 0.54, 95% CI 0.39-0.74) were protective in primiparas, while episiotomy was associated with increased risk in multiparas (OR 2.01, 95% CI 1.18-3.45). Additional factors among primiparas were occipito posterior (OP) delivery (OR 3.35, 95% CI 1.75-6.41) and prolonged second stage (OR 1.98, 95% CI 1.46-2.68), and among multiparas included gestational diabetes (OR 1.78, 95% CI 1.04-3.03) and birth weight >4000g (OR 1.86, 95% CI 1.10-3.15). Parity differences in risk factors such as episiotomy, infant weight, OP delivery, gestational diabetes and prolonged second stage warrant investigation into clinical management. Although rates differ internationally, and replication evidence has confirmed consistency for certain demographic and obstetric factors, the development of internationally endorsed clinical guidelines and further research around interventions to protect the perineum are recommended. Copyright © 2014. Published by Elsevier Ltd.Women and Birth 12/2014; 28(1). DOI:10.1016/j.wombi.2014.10.007 · 1.70 Impact Factor
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ABSTRACT: Background Obstetric anal sphincter injuries (OASIS) might cause anal incontinence (AI) and sexual dysfunction, and might be associated with urinary incontinence (UI). Episiotomy has been identified both as a risk and a protective factor of OASIS. Lately, episiotomies with specific characteristics have shown to be protective against the risk of OASIS. However, little is known about episiotomy characteristics and pelvic floor dysfunction. This study investigates AI, UI, and sexual problems in primiparous women with episiotomy, comparing women with and without OASIS. Associations between episiotomy characteristics and AI, UI, and sexual problems were assessed.Methods This is a matched case¿control study investigating 74 women with one vaginal birth, all with an episiotomy. Among these, 37 women sustained OASIS and were compared to 37 women without OASIS. The two groups were matched for vacuum/forceps. AI, UI and sexual problem symptoms were obtained from St. Mark¿s scoring-tool and self-administered questionnaires. The episiotomy characteristics were investigated and results assessed for the whole group.ResultsThe mean time from birth was 34.5 months (range1.3-78.2) for those with OASIS and 25.9 months (range 7.0-57.4) for those without OASIS, respectively. More women with OASIS reported AI: 14 (38%) vs. 3 (8%) p¿=¿0.05 (OR 4.66, 95% CI 1.34-16.33) as well as more problem with sexual desire p¿=¿0.02 (OR 7.62, 95% CI 1.30-44.64) compared to women without OASIS. We found no association between episiotomy with protective characteristics and dysfunctions.Conclusion Women with OASIS had more AI and sexual problems than those without OASIS. Episiotomy characteristics varied greatly between the women. Episiotomy with protective characteristics was not associated with increased dysfunctions. OASIS should be avoided, and correct episiotomy used if indicated.BMC Women's Health 12/2014; 14(1):157. DOI:10.1186/s12905-014-0157-y · 1.66 Impact Factor
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ABSTRACT: Objectives: To estimate the independent association of episiotomy with obstetric anal sphincter injuries (OASIS) using first a cross-sectional and then a matched pair analysis. Design: A matched cohort. Setting: Data was gathered from the Finnish Medical Birth Register from 2004-2011. Population: All singleton vaginal births (n = 303,758). Methods: Women resulting matched pairs (n = 63,925) were matched based on baseline risk of OASIS defined based on parity (first or second/subsequent vaginal births), age, birth weight, mode of delivery, prior caesarean section, and length of active second stage of birth. Results: In cross-sectional analysis episiotomy was associated with a 12% lower incidence of OASIS (adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.80 to 0.98) in first vaginal births and with a 132% increased incidence of OASIS in second or subsequent vaginal births (aOR 2.32, 95% CI 1.77 to 3.03). In matched pair analysis episiotomy was associated with a 23% (aOR 0.77, 95% CI 0.69 to 0.86) lower incidence of OASIS in first vaginal births and a 61% (aOR 1.61, 95% CI 1.14 to 2.29) increased incidence of OASIS in second or subsequent vaginal births compared to women who gave birth without an episiotomy. The matched pair analysis showed a 12.5% and a 31.6% reduction in aORs of OASIS associated with episiotomy, respectively. Conclusions: A matched pair analysis showed a substantial reduction in the aORs of OASIS with episiotomy, due to confounding by indication. This indicates that results of observational studies evaluating an association between episiotomy and OASIS should be interpreted with caution.PLoS ONE 09/2014; 9(9):e107053. DOI:10.1371/journal.pone.0107053 · 3.53 Impact Factor