Rate Of Obstetric Anal Sphincter Injuries Research Articles

'Hands-off/poised' or 'Hands-on' method among Chinese midwives: A cross-sectional survey.

To determine midwives' preference for "Hands-on" and "Hands-off/poised" methods and to explore the impact factors. With the increasing rate of obstetric anal sphincter injuries, great controversy surrounds the "Hands-on" or "Hands-off" method during childbirth to decrease obstetric anal sphincter injuries incidence. Without regular records and related research, determining the use of this technique in China is difficult. This study used a quantitative study design, following the EQUATOR guidelines (STROBE). A nationwide cross-sectional online survey was conducted using respondent-driven sampling across 31 provinces in China from 1st October 2017-31st December 2017. A total of 6,425 midwives were involved. Descriptive analyses, chi-square test and binary logistic regression were undertaken. A total of 5,225 questionnaires were returned; 55.8% of the participants preferred the "Hands-off/poised" method. The impact factors included hospital categories, total work experience in a birth unit in years, theoretical education and skill training. In the study, for situations with increased OASI risk, 100% of the midwives in the "Hands-off" group expressed willingness to change to the "Hands-on" method whether there was concern about impending obstetric anal sphincter injuries. The "Hands-off/poised" method is heavily practised by Chinese midwives. However, majority of the midwives adopt "Hands-on" method in the face of high risk for obstetric anal sphincter injuries. Further studies are needed to determine the association between obstetric anal sphincter injuries rate and perineal management for low-risk birth. The result indirectly illustrates the application of "Hands-off/poised" technique in China and provides evidence for the international midwifery organisation to understand the status of Chinese midwifery to some extent. It also provides the latest data for further study of these two methods and the study of the relationship between hands-off/poised method and obstetric anal sphincter injuries.

Does the implementation of a restrictive episiotomy policy for operative deliveries increase the risk of obstetric anal sphincter injury?

Our main objective was to investigate whether the implementation of a restrictive episiotomy policy in operative deliveries changes the incidence of obstetric anal sphincter injury (OASI). This is an observational study over an 11-year period in Poitiers University Maternity, France. We included women with vaginal operative deliveries after 34 gestational weeks for singleton births in cephalic presentation. We collected data on the mother and operative delivery characteristics: indication, instrument, epidural analgesia, labor length, episiotomy, OASI, and birthweight. We investigated the changes in the mediolateral episiotomy (MLE) and OASI rates and the association between MLE and OASI. The primary outcome was the evolution of the OASI and MLE rates. The secondary outcome was the occurrence of OASI during operative delivery with or without MLE. In total, 2357 operative deliveries were assessed, including 847 vacuum-, 1350 forceps- and 160 spatula-assisted deliveries. Of these, 950 were performed with MLE and 1407 without; 37 OASIs (3.9%) occurred in the MLE group, and 137 (9.7%) in the no-MLE group. Between 2005 and 2015, MLE use decreased from 78.5 to 16.2% and OASI occurrence increased from 3.1 to 12.7%. The increase in OASI occurrence was significant for forceps deliveries, but not for vacuum or spatula deliveries. Operative delivery with MLE was associated with a three times lower OASI occurrence than that without MLE (adjusted OR = 0.29, 95% CI [0.20-0.43]). Implementation of a restrictive MLE policy for operative delivery seems to be associated with an increase in OASI incidence with forceps, but not with vacuum.

Episcissors-60™ and obstetrics anal sphincter injury: a systematic review and meta-analysis.

The National Health Service (NHS) in England has chosen the Episcissors-60™ as one of the products included in the NHS Innovation Accelerator programme. However, the evidence for its effectiveness is scanty. We therefore set out to systematically review the literature to compare risk of obstetric anal sphincter injury (OASI) in women who had undergone episiotomy with Episcissors-60™ versus those who had an episiotomy with other scissors. Electronic search was performed on the Healthcare Databases Advanced Search (HDAS) platform using the MEDLINE, EMBASE and CINHAL search engines up to September 2018. The search words used were 'Episcissors-60' or 'episcissors 60.' Studies were included if patients who had episiotomies with Episcissors-60™ were compared with parallel or historic patients who had episiotomy with other scissors. The only restriction used was "human" studies. Of the initial 21 citations, 4 studies had enough information to be included in the meta-analysis. The number of study participants ranged from 63 to 4314. When comparing 797 patients who had episiotomies with Episcissors-60™ to 1122 patients who had episiotomies with other scissors, there was a significant reduction in OASI: risk difference = -0.04 (95% CI = -0.07 to -0.01; p = 0.005, I2= 41%). The number needed to treat was 25 (95% CI = 14-100). This was not associated with an increase in episiotomy rate. We reported the first systematic review on the effect of Episcissors-60™ on OASI rate. Although the studies are few, and of small size and low quality, the results are promising in terms of possible reduction in OASI.

The anterior non-episiotomy forceps (ANEF) delivery: Improving the technique of instrumental delivery can minimise perineal and obstetric anal sphincter injury (OASI)

Introduction: Instrumental delivery is associated with an increased risk of obstetric anal sphincter injury (OASI), despite liberal use of episiotomy. OASI rates are high, at 8.9% and 10.9% with routine and restrictive episiotomy, respectively.

Obstetric anal sphincter injuries among women with gestational diabetes and women without gestational diabetes: A NSW population‐based cohort study

Obstetric anal sphincter injuries (OASIs) are associated with maternal morbidity; however, it is uncertain whether gestational diabetes (GDM) is an independent risk factor when considering birthweight mode of birth and episiotomy. To compare rates of OASIs between women with GDM and women without GDM by mode of birth and birthweight. To investigate the association between episiotomy, mode of birth and the risk of OASIs. A population-based cohort study of women who gave birth vaginally in NSW, from 2007 to 2013. Rates of OASIs were compared between women with and without GDM, stratified by mode of birth, birthweight and a multi-categorical variable of mode of birth and episiotomy. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated by multivariable logistic regression. The rate of OASIs was 3.6% (95% CI: 2.6-2.7) vs 2.6% (95% CI: 3.4-2.8; P<0.001) among women with and without GDM, respectively. Women with GDM and a macrosomic baby (birthweight≥4000g) had a higher risk of OASIs with forceps (aOR 1.76, 95% CI: 1.08-2.86, P=0.02) or vacuum (aOR 1.89, 95% CI: 1.17-3.04, P=0.01), compared with those without GDM. For primiparous women with GDM and all women without GDM, an episiotomy with forceps was associated with lower odds of OASIs than forceps only (primiparous GDM, forceps-episiotomy aOR 2.49, 95% CI: 2.00-3.11, forceps aOR 5.30, 95% CI: 3.72-7.54), (primiparous without GDM, forceps-episiotomy aOR 2.71, 95% CI: 2.55-2.89, forceps aOR 5.95, 95% CI: 5.41-6.55) and (multiparous without GDM, forceps-episiotomy aOR 3.75, 95% CI: 3.12-4.50, forceps aOR 6.20, 95% CI: 4.96-7.74). Women with GDM and a macrosomic baby should be counselled about the increased risk of OASIs with both vacuum and forceps. With forceps birth, this risk can be partially mitigated by performing a concomitant episiotomy.

Risk of obstetric anal sphincter injury in women having a vaginal birth after a previous caesarean section: A population-based cohort study

ObjectiveCaesarean section is increasing in prevalence and with it the proportion of women going into their next pregnancy with a scar on their uterus. For women considering vaginal birth after caesarean (VBAC), accurate information about the associated risks is required. Study designThe cohort comprised 192,057 women who had a vaginal delivery of a singleton, term, cephalic infant between the 1st April 2013 and the 31st March 2014 in England: 182,064 women who were having their first baby, and 9993 women who were having a second baby after a previous caesarean delivery. Their risk of an obstetric anal sphincter injury (OASI) was compared using a mixed-effects logistic regression model, adjusting for maternal age, use of instrument, episiotomy, prolonged labour, shoulder dystocia, and demographic factors. ResultsThe OASI rate was 5.0% in primiparous women, 5.8% in secondiparous women undergoing VBAC after previous elective caesarean, and 7.6% in secondiparous women undergoing VBAC after previous emergency caesarean. Women having a VBAC for their second baby following an emergency caesarean section in their first delivery had a higher rate of OASI than primiparous women (adjusted OR 1.31; 95% CI: 1.20, 1.43), For women with a previous elective delivery, the rates are similar to those for primiparous women. ConclusionWomen having a VBAC after emergency caesarean have a higher rate of OASI than primiparous women. This is important in the counselling of women considering VBAC.

Single prior caesarean section and risk of anal sphincter injury.

Injury to the anal sphincter at vaginal delivery remains the leading cause of faecal incontinence in women. Previous studies reported an increased incidence of obstetric anal sphincter injury (OASI) in women attempting vaginal birth after caesarean section (VBAC). The aim of the paper was to establish whether women in their second pregnancy, with one previous uterine scar, are at a higher risk of OASI compared with nulliparous women. All primiparous and secundiparous women with a previous caesarean section who delivered from 2008 to 2017 were analysed in a single-centre retrospective study. The primary endpoint was OASI. Labour characteristics in both groups were compared, and a multiple regression model was created. There were 8573 vaginal deliveries of nulliparous women and 3453 deliveries of women in their second pregnancy with a previous caesarean section, of whom 550 had a successful VBAC. There was no significant difference in the rate of OASI between primiparous women and those who had a successful VBAC: 3.5% (297/8573) versus 3.1% (17/550), P = 0.730). Foetal macrosomia (>4kg) and forceps delivery were risk factors for sphincter injury, while episiotomy and epidural anaesthesia were protective. VBAC does not confer an increased risk of OASI after a first delivery by caesarean section when compared with nulliparous women. The rate of successful VBAC may be contributory and suggests that the risk conferred by VBAC may be unit-specific. Unit and national-level audit is necessary to investigate this risk further.

Evaluation of Accuracy of Episiotomy Incision in a Governmental Maternity Unit in Palestine: An Observational Study.

Episiotomy should be cut at certain internationally set criteria to minimize risk of obstetric anal sphincter injuries (OASIS) and anal incontinence. The aim of this study was to assess the accuracy of cutting right mediolateral episiotomy (RMLE). An institution-based prospective cohort study was undertaken in a Palestinian maternity unit from February 1, to December 31, 2016. Women having vaginal birth at gestational weeks ≥24 or birthweight ≥1000 g and with intended RMLE were eligible (n=240). Transparent plastic films were used to trace sutured episiotomy in relation to the midline within 24-hour postpartum. These were used to measure incisions' distance from midline, and suture angles were used to classify the incisions into RMLE, lateral, and midline episiotomy groups. Clinical characteristics and association with OASIS were compared between episiotomy groups. A subanalysis by profession (midwife or trainee doctor) was done. Less than 30% were RMLE of which 59% had a suture angle of <40° (equivalent to an incision angle of <60°). There was a trend of higher OASIS rate, but not statistically significant, in the midline (16%, OR: 1.7, CI: 0.61–4.5) and unclassified groups (16.5%, OR: 1.8, CI: 0.8–4.3) than RMLE and lateral groups (10%). No significant differences were observed between episiotomies cut by doctors and midwives. Most of the assessed episiotomies lacked the agreed criteria for RMLE and had less than optimal incision angle which increases risk of severe complications. A well-structured training program on how to cut episiotomy is recommended.

A multi-centre quality improvement project to reduce the incidence of obstetric anal sphincter injury (OASI): study protocol

BackgroundThird and fourth degree perineal tears, or obstetric anal sphincter injuries (OASI), sustained during childbirth can result in anal incontinence and psychosocial problems which require ongoing treatment. Within the English National Health System (NHS) reported rates of OASI have gradually increased. In response, a care bundle was developed incorporating four elements: 1) antenatal information to women, 2) manual perineal protection during all vaginal births, 3) episiotomy to be performed with a 60° mediolateral angle at crowning (when clinically indicated) and 4) perineal examination (including per rectum) after childbirth. Implementation of the OASI Care Bundle is aided by a skills development module and an awareness campaign. The project is a collaboration between two national professional bodies, an NHS hospital trust and an academic institution.MethodsImplementation of the OASI Care Bundle will be evaluated using a stepped-wedge design. From January 2017 sixteen maternity units across England, Wales and Scotland will participate in the study over a 15-month period, with sequential roll-out of the intervention in four blocks (regions) of four units. The primary clinical outcome is OASI rate. Regression analysis will adjust for differences in organisational characteristics and obstetric risk factors in women who gave birth before and after implementation of the care bundle. Focus group discussions and in-depth interviews with clinicians will evaluate the feasibility of integrating the care bundle into routine practice. Interviews with women will explore the acceptability of the intervention.DiscussionThis protocol outlines the evaluation of our quality improvement project which aims to prevent OASI using a bundle of evidence-based interventions that are each widely used in practice. The OASI project aims to 1) standardise practice to prevent OASI in a way that is acceptable to clinicians and women and 2) identify the barriers and enablers associated with upscaling interventions within maternity units. If found to be effective, feasible and acceptable, the OASI Care Bundle will be shared with a range of audiences using the communication channels available to the professional bodies.Trial registrationThe OASI Project was retrospectively registered on the ISCTRN12143325 database date assigned 03/10/2017.

Atraumatic normal vaginal delivery: how many women get what they want?

Trauma to the perineum, levator ani complex, and anal sphincter is common during vaginal childbirth, but often clinically underdiagnosed, and many women are unaware of the potential for long-term damage. In this study we use transperineal ultrasound to identify how many women will achieve a normal vaginal delivery without substantial damage to the levator ani or anal sphincter muscles, and to create a model to predict patient characteristics associated with successful atraumatic normal vaginal delivery. This is a retrospective, secondary analysis of data sets gathered in the context of an interventional perinatal imaging study. A total of 660 primiparas, carrying an uncomplicated singleton pregnancy, underwent an antepartum and postpartum interview, vaginal exam (Pelvic Organ Prolapse Quantification), and 4-dimensional translabial ultrasound. Ultrasound data were analyzed for levator trauma and/or overdistention and residual sphincter defects. Postprocessing analysis of ultrasound volumes was performed blinded against clinical data and analyzed against obstetric data retrieved from the local maternity database. Levator avulsion was diagnosed if the muscle insertion at the inferior pubic ramus at the plane of minimal hiatal dimensions and within 5 mm above this plane on tomographic ultrasound imaging was abnormal, ie the muscle was disconnected from the inferior pubic ramus. Hiatal overdistensibility (microtrauma) was diagnosed if there was a peripartum increase in hiatal area on Valsalva by >20% with the resultant area ≥25 cm2. A sphincter defect was diagnosed if a gap of >30 degrees was seen in ≥4 of 6 tomographic ultrasound imaging slices bracketing the external anal sphincter. Two models were tested: a first model that defines severe pelvic floor trauma as either obstetric anal sphincter injury or levator avulsion, and a second, more conservative model, that also included microtrauma. A total of 504/660 women (76%) returned for postpartum follow-up as described previously. In all, 21 patients were excluded due to inadequate data or intercurrent pregnancy, leaving 483 women for analysis. Model 1 defined nontraumatic vaginal delivery as excluding operative delivery, obstetric anal sphincter injuries, and sonographic evidence of levator avulsion or residual sphincter defect. Model 2 also excluded microtrauma. Of 483 women, 112 (23%) had a cesarean delivery, 103 (21%) had an operative vaginal delivery, and 17 (4%) had a third-/fourth-degree tear, leaving 251 women who could be said to have had a normal vaginal delivery. On ultrasound, in model 1, 27 women (6%) had an avulsion and 31 (6%) had a residual defect, leaving 193/483 (40%) who met the criteria for atraumatic normal vaginal delivery. In model 2, an additional 33 women (7%) had microtrauma, leaving only 160/483 (33%) women who met the criteria for atraumatic normal vaginal delivery. On multivariate analysis, younger age and earlier gestation at time of delivery remained highly significant as predictors of atraumatic normal vaginal delivery in both models, with increased hiatal area on Valsalva also significant in model 2 (all P ≤ .035). The prevalence of significant pelvic floor trauma aftervaginal child birth is much higher than generally assumed. Ratesofobstetric anal sphincter injury are often underestimated and levator avulsion is not included as a consequence of vaginal birth in most obstetric text books. In this study less than half (33-40%) of primiparous women achieved an atraumatic normal vaginal delivery.

Implementation of the RCOG guidelines for prevention of obstetric anal sphincter injuries (OASIS) at two London Hospitals: A time series analysis

ObjectiveTo audit the impact of implementation of the RCOG guidelines for prevention of Obstetric anal sphincter injuries (OASIS) by introducing antenatal perineal massage, manual perineal protection, and cutting episiotomies at 60° to the midline at the time of crowning. DesignTime series analysis; Setting – Two London teaching hospitals; Royal Free London (RFL) and Barnet; Population or Sample – All nulliparous women undergoing vaginal birth; Methods – Training was provided for above techniques. EPISCISSORS-60 were introduced to perform 60° episiotomies. Data were extracted from maternity databases and dashboards; Main Outcome Measures – OASIS rates before and after implementation. ResultsData from 2566 births were analysed. In operative vaginal deliveries (OVD), OASIS declined from 9.6% to 2% (p = 0.001) at Barnet and from 5.6% to 4.2% (p = 0.4) at RFL. OASIS reduced in nulliparous OVD’s given episiotomies from 6.3% in the ‘before’ period to 0.6% in the ‘after’ period [p = 0.01] at Barnet. Before introduction of the EPISCISSORS-60, OASIS rate was 6.3% with episiotomies and 30% without episiotomies (p = 0.000). After introduction of the EPISCISSORS-60, OASIS rate was 0.63% with episiotomies v 16% without episiotomies (p = 0.000) at Barnet. At RFL, OASIS rate was 2.6% with episiotomies, and 42% without episiotomy (p = 0.000).In SVD’s at Barnet, OASIS declined from 6.6% before to 0% after (p = 0.000) in women given episiotomies while it declined from 5.4% to 3% (p = 0.12) in those not given episiotomies. After introduction of the EPISCISSORS-60, OASIS was 0% in women with episiotomies and 3% in those without episiotomies (p = 0.04).In SVD’s at RFL, OASIS was 0% in women given episiotomy v 4.7% without episiotomy (p = 0.03). ConclusionsDeliveries with EPISCISSORS-60 episiotomies had lesser OASIS than those without episiotomies in both nulliparous OVD’s and SVD’s. OASIS was lower with EPISCISSORS-60 episiotomies than those with eyeballed episiotomies.

Interventional program to reduce both the incidence of anal sphincter tears and rate of Caesarean sections

ObjectiveTo estimate the ability of an intensive interventional program to decrease the number of obstetric anal sphincter injuries (OASIS), while simultaneously decreasing the rate of Caesarean sections (CS). Study designThe intervention, which aimed at decreasing the number of OASIS, started with a compulsory tutorial for all the midwives and physicians. At the same time, the clinic initiated a program to decrease the number of CS. We compared the outcomes before and after the intervention by calculating the risk ratios with 95% confidence intervals. The changes in selected outcomes were also tested using the test of relative proportions. The follow-up was extended for 1 year after the intervention. ResultsThe number of deliveries by CS decreased significantly, as did the number of OASIS in all the subgroups, except for the multi-parous women. The rate of OASIS for instrumental deliveries (mostly by vacuum) decreased significantly (p < 0.003), as compared to pre-interventional period. The number of Grade 4 tears decreased significantly: from 0.4 ruptures per 100 deliveries before the start of the intervention to 0.1 ruptures after the start of the intervention (RR 0.37, 95% CI 0.14–0.98, p = 0.037). However, the OASIS and Grade 4 sphincter injuries increased with forceps delivery. The CS rate decreased from 17.7 to 15.0 per 100 deliveries (RR 0.85, 95% CI 0.78–0.93). The post-interventional follow-up period revealed a further decrease in the frequency of OASIS (to 1.28%, p < 0.001) and a stable CS rate (14.2%). ConclusionThe intervention significantly decreases the frequency of OASIS, in line with the results obtained for earlier interventions. At the same time, a decrease in CS rate was obtained.

The effectiveness of mediolateral episiotomy in preventing obstetric anal sphincter injuries during operative vaginal delivery: a ten-year analysis of a national registry.

Obstetric anal sphincter injuries (OASIS) are associated with an increased risk of faecal incontinence after vaginal delivery. The aim of this retrospective population-based cohort study was to assess whether mediolateral episiotomy is associated with a reduction in the rate of OASIS during operative vaginal delivery. We used data from the Dutch Perinatal Registry (Perined) that includes records of almost all births between 2000 and 2010 in The Netherlands. In a cohort of 170,969 primiparous and multiparous women whose delivery was recorded, we estimated the association between mediolateral episiotomy and OASIS following both vacuum and forceps deliveries using univariate and multivariate logistic regression analysis. The incidences of OASIS following vacuum delivery in 130,157 primiparous women were 2.5% and 14% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.14, 95% CI 0.13-0.15), and in 29,183 multiparous women were 2.0% and 7.5%, respectively (adjusted OR 0.23, 95% CI 0.21-0.27). The incidences of OASIS following forceps delivery in 9,855 primiparous women were 3.4% and 26.7% in those with and without a mediolateral episiotomy, respectively (adjusted OR 0.09, 95% CI 0.07-0.11), and in 1,774 multiparous women were 2.6% and 14.2%, respectively (adjusted OR 0.13, 95% CI 0.08-0.22). The use of a mediolateral episiotomy during both vacuum delivery and forceps delivery is associated with a fivefold to tenfold reduction in the rate of OASIS in primiparous and multiparous women.

Risk Factors for Obstetric Anal Sphincter Injury in a Diverse Population [1C

INTRODUCTION: We evaluated risk factors for obstetric anal sphincter injuries (OASIS) and determined the effect of duration of second stage of labor (DSS) on OASIS risk. METHODS: We included term, singleton, cephalic vaginal deliveries within Kaiser Permanente Northern California over two years. Bivariate analysis identified OASIS risk factors. Multiple logistic regression helped eliminate confounding. Classification and Regression Tree (CART) recursive partitioning created decision nodes based on risk factors. DSS was grouped into 15-minute intervals to examine effect magnitude. RESULTS: Of 22,741 deliveries included, 93.8% were spontaneous and 6.2% were vacuum-assisted. The OASIS rate was 4.9%. Multiple logistic regression identified Asian race (OR 2.4, CI 2.1-2.8), vacuum delivery (OR 4.6, CI 3.9-5.4), DSS greater than 75 minutes (OR 2.4, CI 2.1-2.8), VBAC (OR 2.8, CI 2.1-3.8), and nulliparity (OR 1.7, CI 1.4-2.1) as independent risk factors for OASIS. DSS ranged from 0-680 minutes. Median length was 95 minutes for nulliparous and 27 minutes for multiparous women. The first CART decision node was DSS greater than 75 minutes. Each additional 15 minutes of pushing resulted in 1.07 (p &lt; 0.001) increase in the odds of OASIS in nulliparous women and 1.14 (p &lt; 0.001) in multiparous women. CART analysis identified Asian women delivered via vacuum after a greater than 75 minute second stage as the subpopulation with highest risk of OASIS at 43%. CONCLUSION: Risk factors for highest rates of OASIS were identified. Each incremental increase in DSS confers an increase in OASIS risk. Changing management based on our findings could improve outcomes for laboring women.

Fetal Maternal Size Disproportion: Explanation for the Racial Disparity of OASIS? [7R

INTRODUCTION: Obstetric anal sphincter injuries (OASIS) are a significant complication of vaginal deliveries. Asian race is a known independent predictor of perineal trauma. Limited data demonstrate a plausible explanation of this racial disparity. We aim to assess the relationship between the fetal maternal size disproportion as measured by fetal birth weight to prepregnancy BMI ratio (BW:BMI) and OASIS in mothers of different race groups. METHODS: Retrospective cohort study of vaginal deliveries between 2006 and 2015. Demographics and obstetrical data were abstracted and compared. The significance of BW:BMI to OASIS was evaluated. Results adjusted for confounding factors. RESULTS: 16,024 vaginal deliveries were included. 28.5% had no lacerations, 64.6% had 1st or 2nd degree lacerations, and 6.9% had OASIS. Demographic factors associated with OASIS included Asian race, nulliparity, increased age, increased birth weight, episiotomy, trial of labor after cesarean, and operative vaginal deliveries. Although BMI was not an independent risk factor, BW:BMI showed a significant relationship with OASIS. For every 10 unit increase in BW:BMI, the adjusted odds of having an OASIS increased by 16% (p= &lt; .001). After adjusting for BW:BMI, Asian race had higher OASIS rates. Interaction between race groups and BW:BMI was only significant for 1st and 2nd degree lacerations, not OASIS. CONCLUSION: This study verified known risk factors associated with OASIS. Increasing BW:BMI is associated with OASIS. However, BW:BMI does not provide insight into OASIS racial disparities; further investigations are needed to understand why Asian race is an OASIS risk factor.

Obstetric Anal Sphincter Injuries (OASIs) in Israel: A Review of the Incidence and Risk Factors.

Obstetric anal sphincter injuries (OASIs) following vaginal deliveries are the main reason for subsequent development of anal incontinence in women. The diagnosis of such tears is crucial for treating and preventing such a grave sequela. The reported rate of OASIs in Israel was between 0.1% and 0.6%, out of all vaginal births, which is 10-fold lower than that reported in Europe and the United States. Structured hands-on training in repair of OASIs in seven medical centers in Israel significantly increased the detection rate of third-degree perineal tears. The implementation of such programs is crucial for increasing awareness and detection rates of OASIs following vaginal deliveries.

Reducing obstetric anal sphincter injuries using perineal support: our preliminary experience.

Obstetric anal sphincter injuries (OASIs) are associated with significant short-term and long-term morbidity. Over the past decade, there has been a steady rise in the rate of OASIs. There is therefore a compelling need to identify strategies to minimize OASIs. The objective of this study was to determine if perineal support at the time of vaginal delivery can reduce the incidence and severity of OASIs. All labour ward staff including midwives and doctors were invited to train in the technique of perineal support during vaginal delivery. Two experts from Norway conducted workshops with practical hands-on training on pelvic models. The midwives and doctors underwent further training with women in labour, and mandatory training was continued within the department. All midwives and doctors were instructed to support the perineum during both spontaneous and assisted vaginal delivery. From April 2011 to November 2014, 11,135 women underwent vaginal delivery. The OASI rate decreased from 4.7% to 4.1% (p = 0.11). There was a significant reduction (0.9% to 0.3%, p < 0.001) in 3c third-degree and fourth-degree tears (major OASIs). In a multivariate analysis, perineal support was associated with a significant reduction in the rates of OASIs (23%; OR 0.77, 95% CI 0.63-0.95, p = 0.01]) and major OASIs (71%; OR 0.34, 95% CI 0.17-0.69, p = 0.03). This interventional study showed that perineal support during vaginal delivery can reduce the risk of major OASIs. With sustained reinforcement of this intervention programme, we anticipate a further reduction in OASI rates.

Obstetric anal sphincter injuries: review of anatomical factors and modifiable second stage interventions

Obstetric anal sphincter injuries (OASIs) are the leading cause of anal incontinence in women. Modification of various risk factors and anatomical considerations have been reported to reduce the rate of OASI. A PubMed search (1989–2014) of studies and systematic reviews on risk factors for OASI. Perineal distension (stretching) of 170 % in the transverse direction and 40 % in the vertical direction occurs at crowning, leading to significant differences (15–30°) between episiotomy incision angles and suture angles. Episiotomies incised at 60° achieve suture angles of 43–50°; those incised at 40° result in a suture angle of 22°. Episiotomies with suture angles too acute ( 60°) are associated with an increased risk of OASI. Suture angles of 40–60° are in the safe zone. Clinicians are poor at correctly estimating episiotomy angles on paper and in patients. Sutured episiotomies originating 10 mm away from the midline are associated with a lower rate of OASIs. Compared to spontaneous tears, episiotomies appear to be associated with a reduction in OASI risk by 40–50 %, whereas shorter perineal lengths, perineal oedema and instrumental deliveries are associated with a higher risk. Instrumental deliveries with mediolateral episiotomies are associated with a significantly lower OASI risk. Other preventative measures include warm perineal compresses and controlled delivery of the head. Relieving pressure on the central posterior perineum by an episiotomy and/or controlled delivery of the head should be important considerations in reducing the risk of OASI. Episiotomies should be performed 60° from the midline. Prospective studies should evaluate elective episiotomies in women with a short perineal length and application of standardised digital perineal support.

Obstetric Anal Sphincter Injury as a Quality Metric: 16-Year Experience at a Single Institution.

To evaluate trends in annual rates of vaginal birth, cesarean delivery, and obstetric anal sphincter injury at a single institution before and after the designation of obstetric anal sphincter injury as a measure of obstetric quality and safety. This was a retrospective cohort study of women undergoing a singleton vaginal delivery and diagnosed with obstetric anal sphincter injury over a 16-year period. International Classification of Diseases, 9th Revision codes for perineal lacerations were used as identifiers. Trends in annual cesarean delivery, perineal laceration, and obstetric anal sphincter injury rates were assessed in a linear regression model. The data were divided into two time periods (1998-2005 and 2006-2013) based on the year (2006) in which obstetric anal sphincter injury was designated as a quality marker and compared. A total of 1,366 women had obstetric anal sphincter injury, and 1,360 were included for analysis. There was a 12.1% decline in annual vaginal delivery rates (from 77.1% to 67.8%) and a 40.6% increase in annual cesarean delivery rate (from 22.9% to 32.2%; P<.001). The rate of first-degree and second-degree laceration increased significantly (P=.009), and obstetric anal sphincter injury decreased significantly (P<.001). Operative vaginal birth and episiotomy were associated with obstetric anal sphincter injury in 2006-2013 compared with 1998-2005 (P<.001 and P=.018, respectively). After the designation of obstetric anal sphincter injury as an institutional quality measure, rates of obstetric anal sphincter injury decreased.

Obstetric anal sphincter injuries after episiotomy: systematic review and meta-analysis.

IntroductionThere is conflicting evidence on whether mediolateral episiotomy (MLE) reduces the risk of obstetric anal sphincter injuries (OASI) in spontaneous vaginal deliveries (SVD).ObjectivesA systematic review was undertaken to compare rates of OASI amongst women who had undergone mediolateral episiotomy versus those who did not.MethodsᅟSearch strategyElectronic searches were performed in literature databases: CINAHL, Cochrane, EMBASE, Medline and MIDIRS from database inception to July 2015. Studies were eligible if MLE was compared to spontaneous tears and if OASI was the outcome of interest.Two reviewers independently selected and extracted data on study characteristics, quality and results. We computed events of OASI in those who did and did not have an episiotomy from individual studies and pooled these results in a meta-analysis where possible.Main resultsOf the 2090 citations, 16 were included in the review. All were non-randomised, population based or retrospective cohort studies. There was great variation in quality amongst these studies. Data from 7 studies was used for meta-analysis. On collating data from these studies where the majority of women (636755/651114) were nulliparous, MLE reduced the risk of OASI (RR 0.67 95 % CI 0.49-0.92) in vaginal delivery.ConclusionThe pooled analysis of a large number of women undergoing vaginal birth, most of who were nulliparous, indicates that MLE has a beneficial effect in prevention of OASI. An accurately given MLE might have a role in reducing OASI and should not be withheld, especially in nulliparous women. Caution is advised as the data is from non-randomised studies.