Mediolateral episiotomy reduces risk for anal sphincter injury during operative vaginal delivery

Department of Obstetrics and Gynaecology, Ikazia Hospital, Rotterdam, The Netherlands.
BJOG An International Journal of Obstetrics & Gynaecology (Impact Factor: 3.45). 02/2008; 115(1):104-8. DOI: 10.1111/j.1471-0528.2007.01554.x
Source: PubMed


To determine the risk factors for anal sphincter injuries during operative vaginal delivery.
A population-based observational study.
All 21 254 women delivered with vacuum extraction and 7478 women delivered with forceps, derived from the previously validated Dutch National Obstetric Database from the years 1994 to 1995.
Anal sphincter injury was defined as any injury, partial or complete, of the anal sphincters. Risk factors were determined with multivariate logistic regression analysis.
Individual obstetric factors, e.g. fetal birthweights, duration of second stage, etc.
Anal sphincter injury occurred in 3.0% of vacuum extractions and in 4.7% of forceps deliveries. Primiparity, occipitoposterior position and fetal birthweight were associated with an increased risk for anal sphincter injury in both types of operative vaginal delivery, whereas duration of second stage was associated with an increased risk only in vacuum extractions. Mediolateral episiotomy protected significantly for anal sphincter damage in both vacuum extraction (OR 0.11, 95% CI 0.09-0.13) and forceps delivery (OR 0.08, 95% CI 0.07-0.11). The number of mediolateral episiotomies needed to prevent one sphincter injury in vacuum extractions was 12, whereas 5 mediolateral episiotomies could prevent one sphincter injury in forceps deliveries.
Primiparity and occipitoposterior presentation are strong risk factors for the occurrence of anal sphincter injury during operative vaginal delivery. The highly significant protective effect of mediolateral episiotomies in both types of operative vaginal delivery warrants the conclusions that this type of episiotomy should be used routinely during these interventions to protect the anal sphincters.

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Available from: Jan Willem De Leeuw, Oct 16, 2014
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    • "Study Methods Primipara Maternal age Birth weight Prolonged second stage of birth Operative vaginal Episiotomy (rate), ml= mediolateral, m=midline Epidural analgesia Occiput posterior de Leeuw et al. 2008 Population based register, cohort, n=21,254, 1994-1995, Netherlands aOR 1.94 ( "
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    ABSTRACT: ABSTRACT Obstetric anal sphincter rupture (OASR) is a well-known complication of vaginal delivery; it can have serious implications for women’s health since it results in anal incontinence in 20-60% of those affected. The incidence of OASR varies widely; in 2008 it was reported at a level of 0.9% in Finland but 2.6-5.6% in the other Nordic countries. The purpose of this study was to identify the risk factors for OASR, and to describe trends in the incidence of OASR and episiotomy between 1997 and 2007 in Finland. A population-based inventory of 514,741 women with singleton vaginal deliveries, including all presentations and assisted deliveries, recorded in the Finnish Medical Birth Register was analyzed. For the years 1997-2003, the information on OASR was taken from the Hospital Discharge Register (HDR). Primiparous (=first vaginal delivery) (n=2,315) and multiparous (n=534) women with OASR were compared in terms of possible risk factors to primiparous (n=215,463) and multiparous (n=296,429) women without OASR, respectively, using stepwise logistic regression analysis. The risk factors for OASR included forceps delivery, a prolonged active second stage of birth, delivery of an infant weighing more than 4,000 grams, and vacuum assistance. Lateral episiotomy was associated with a 17% lower risk of OASR among primiparous women in spontaneous vaginal deliveries; however this approach was inefficient since more than 900 primiparous women must be exposed to an episiotomy to prevent a single OASR. In vacuum assisted deliveries among primiparous women the equivalent number was 66, which is clinically more acceptable. Correspondingly, among the multiparous women, episiotomy was associated with a doubling of the risk of OASR. Furthermore, pain management was associated with 13-52% lower risk of OASR among both groups of women except epidural analgesia among the multiparous women that increased the risk 1.5-fold. In Finland, the incidence of OASR has increased, from 0.2% in 1997 to 0.9% in 2007. The likelihood of OASR increased 3.28-fold among primiparous and 2.83-fold among multiparous women during the study period, 1997– 2007. Changes in population characteristics and in the use of interventions were small, and consequently did not cause the increased OASR rate. The only exception was vacuum assisted deliveries, which explained about 9% of the rising OASR risk, in line with the increased use of this technique. The results of this study suggest that time factors were of minor importance to the increasing rate of OASR, because the risk of it was shown to be 11% lower during the night than daytime and 15% lower in July (the most popular holiday month) than other months. In fact, ca. 3- to 8-fold inter-hospital differences in OASR risks in primiparous and multiparous women, respectively, were of greater importance. Hospitals with high rates of OASR for primiparous women also had high rates for multiparous women, implying that treatment differences might have played a crucial role in the variations or that there were differences in registration routines or in diagnosing OASR. The results suggest that episiotomy provided protection from OASR in the first vaginal birth, but was a risk factor in multiparous women. Among the multiparous women, episiotomy was performed prophylactically more often in those who were at a high risk of OASR than in low risk women, consequently there might have been confounding by indication. The results indicate the value of selective use of lateral episiotomy, and its routine use might be advisable in vacuum assisted deliveries for primiparous women. Inter-hospital differences suggest that, between the hospitals, there may be an important healthcare quality issue or differences in recording or diagnosing OASR. National Library of Medicine Classification: WQ415; WQ330; WP170 Medical Subject Headings (MeSH): Delivery, Obstetric; Obstetric Labor Complications; Anal Canal +injuries; Rupture +epidemiology; Episiotomy; Registries
    Full-text · Thesis · Mar 2011
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    • "In Finland, the increase in OASR rate is substantial, from 0.2% in 1997 to 0.9% in 2007 [2]. Generally, it has been observed that the highest rates are associated with the greatest use of medical interventions during birth [4] and consequently some interventions and demographic characteristics such as vacuum extraction [5-7], forceps delivery [7,8], mediolateral episiotomy [9,10], midline episiotomy [11,12], primiparity [5,8,13,14], a prolonged second stage of delivery [8,15], occiput posterior presentation [5,13,14] and a high birth weight [5,6,8,13] are well-known risk factors for OASR. "
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    ABSTRACT: Obstetric anal sphincter rupture (OASR) is a serious complication of delivery, which frequently results in faecal incontinence despite primary repair and has serious implications for women's health. The objective of this study was to assess whether human factors, workload and staffing at night, at weekends and during holidays has an effect on the increasing OASR rates among all singleton vaginal deliveries (n = 514,741) having occurred between 1997 and 2007 in Finland. Women (n = 2,849) with OASR were compared in terms of possible risk factors to women without OASR using stepwise logistic regression analysis. In Finland, the increase in OASR rate is striking, from 0.2% in 1997 to 0.9% in 2007. OASR rates varied from 0.49% to 0.58% (</= 0.001) according to the time of day, and were lowest at night. After adjustment for patient-mix and the use of interventions, the risk of OASR was 11% lower (95% CI 3-18%) at night and 15% lower (95% CI 3-26%) in July - the main holiday month. Only 14% of the increased OASR risk during the day time (8-23.59) was attributable to vacuum assistance and birth weight, whereas the holiday period had no effect. Decreased OASR rates at night and in July suggest that human factors such as decreased alertness due to fatigue or hospitals' administrative factors such as workload and staffing did not increase the rates of OASR.
    Full-text · Article · Feb 2010 · BMC Research Notes
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    ABSTRACT: This article focuses on the prevention, identification, and management of urinary and fecal incontinence in the perinatal period. Both urinary and fecal incontinence are common concerns affecting women throughout pregnancy, intrapartum, and postpartum. These are the problems that are not approached by healthcare providers during the initial antepartal assessment, nor are they fully investigated after delivery. Many women hesitate to disclose this information. Women tend to consider this to be a minor discomfort of pregnancy and a consequence resulting from childbirth in the postpartum period. Intervention strategies and nursing care components in the perinatal period will be presented.
    No preview · Article · Nov 2009 · The Journal of perinatal & neonatal nursing
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