Caesarean section and anal incontinence in women after obstetric anal sphincter injury: A systematic review and meta-analysis.

BACKGROUND: Approximately 50% women who give birth after obstetric anal sphincter injury (OASI) develop anal incontinence (AI) over their lifetime. OBJECTIVE: To evaluate current evidence for a protective benefit of planned caesarean section (CS) to prevent AI after OASI. SEARCH STRATEGY: MEDLINE/PubMed, Embase 1974-2024, CINAHL and Cochrane to 7 February 2024 (PROSPERO CRD42022372442). SELECTION CRITERIA: All studies reporting outcomes after OASI and a subsequent birth, by any mode. DATA COLLECTION AND ANALYSIS: Eighty-six of 2646 screened studies met inclusion criteria, with nine studies suitable to meta-analyse the primary outcome of 'adjusted AI' after OASI and subsequent birth. Subgroups: short-term AI, long-term AI, AI in asymptomatic women. SECONDARY OUTCOMES: total AI, quality of life, satisfaction/regret, solid/liquid/flatal incontinence, faecal urgency, AI in women with and without subsequent birth, change in AI pre- to post- subsequent birth. MAIN RESULTS: There was no evidence of a difference in adjusted AI after subsequent vaginal birth compared with CS after OASI across all time periods (OR = 0.92, 95% CI 0.72-1.20; 9 studies, 2104 participants, I2 = 0% p = 0.58), for subgroup analyses or secondary outcomes. There was no evidence of a difference in AI in women with or without subsequent birth (OR = 1.00 95% CI 0.65-1.54; 10 studies, 970 participants, I2 = 35% p = 0.99), or pre- to post- subsequent birth (OR = 0.79 95% CI 0.51-1.25; 13 studies, 5496 participants, I2 = 73% p = 0.31). CONCLUSIONS: Due to low evidence quality, we are unable to determine whether planned caesarean is protective against AI after OASI. Higher quality evidence is required to guide personalised decision-making for asymptomatic women and to determine the effect of subsequent birth mode on long-term AI outcomes.

Obstetric Characteristics and Functional Outcomes in Women with Obstetric Anal Sphincter Injury.

BACKGROUND: Obstetric anal sphincter injury is a complication of vaginal delivery, if left untreated, causes significant maternal morbidities; urinary problems and fecal/ flatus incontinence. The aim of this study was to determine the incidence and describe the obstetric characteristics and functional outcomes of women who had vaginal delivery at Paropakar Maternity and Women's Hospital Nepal and sustained Obstetric anal sphincter injury. METHODS: This retrospective descriptive study included women who had vaginal delivery, irrespective of parity, in the labor room or birthing unit of Paropakar Maternity and Women's Hospital from April 2018 to September 2020, and sustained Grade III or IV Obstetric anal sphincter injury after 28 weeks period of gestation. Maternal characteristics, obstetric details and perineal status after vaginal delivery were noted after review of hospital records. The patients were further inquired via telephone for their current status of fecal and/or urinary incontinence. RESULTS: The incidence of OASI was 106 (0.33%) among 31, 786 Nepalese women with vaginal birth over a 2-year period. The mean age women with Obstetric anal sphincter injury was 24.6 ± 4.3 years and 45(52.9%) cases belonged to Janajati ethnicity. Fifty two (61.2 %) were primipara and 77 (90.6%) had spontaneous vaginal deliveries. Episiotomy was not performed on most of the patients (63, 74.1%). Problems with flatus holding, stool holding and urine holding was reported by 28.3%, 13.2% and 22.6% women respectively. CONCLUSIONS: The incidence of Obstetric anal sphincter injury among Nepalese women with vaginal birth over a 2-year period was 0.33%, which was lower than other South Asian studies. Grade III Obstetric anal sphincter injury was the frequent most type. The injuries were more common in women with Janajati ethnicity, primipara and women who did not have episiotomy. Problems with flatus holding and urine holding were present in almost one-fourth of the women with Obstetric anal sphincter injury at follow up.

Episiotomy: Are Indian Obstetricians Getting the Angle Right?

Background: A mediolateral episiotomy is recommended when indicated at a 60° angle at crowning, to avoid obstetric anal sphincter injuries (OASIs) by episiotomies angled too close or distant to the anus. This study surveyed obstetricians in India regarding the recommended episiotomy angle and their ability to correctly draw the angle. Methods: Workshops were conducted in India to share knowledge in the prevention and repair of OASIs. A questionnaire was distributed prior to the workshop. Participants were asked to describe the recommended episiotomy angle and to draw this on a paper replica of the perineum. The intra-class correlation coefficient (ICC) was calculated to assess the inter-rater reliability between the angle stated and drawn. A 2° difference was deemed acceptable. Standard errors of measurement (SEM) were calculated to measure the range of error of each measurement. Results: One hundred and forty doctors participated. 47.9% described the angle of an episiotomy to be 60°. Only 2.2% drew an angle of 60°, but 8.7% (n = 12) drew between 58 and 62°. Only 5.8% (n = 6) of doctors correctly drew the episiotomy angle they described. There was poor agreement ICC = 0.18 (- 0.01 to 0.36) with a SEM of ± 12.2°. Conclusions: Knowledge surrounding the recommended episiotomy angle is lacking. Doctors are failing to estimate their desired episiotomy angle. This highlights the need for national guidelines, the creation and validation of structured training programmes to improve accuracy, or using fixed-angle devices such as the EPISCISSORS-60 or other proven measurement aids to minimise preventable harm due to human error.

Obstetric anal sphincter injuries during instrumental vaginal delivery: An observational study based on 18-years of real-world data.

OBJECTIVE: To determine the prevalence and secular trends of obstetric anal sphincter injuries (OASIS) in vacuum and forceps deliveries in Norway, both with and without episiotomy. DESIGN: Population-based real-world data collected during 2001-2018. SETTING: Medical Birth Registry Norway. POPULATION OR SAMPLE: Nulliparous women with singleton foetuses in a cephalic presentation delivered by either vacuum or forceps (n = 70 783). METHODS: Logistic regression analyses were applied to the OASIS prevalence in six 3-year time periods. Both crude odds ratios and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were determined. MAIN OUTCOME MEASURES: OASIS prevalence. RESULTS: The OASIS prevalence in vacuum and forceps deliveries decreased from 14.8% during 2001-2003 to 5.2% during 2016-2018. The overall reduction between the first and last 3-year time period was 61% (aOR = 0.39, 95% CIs = 0.35-0.43). The only exception to this decreasing trend in OASIS was found in forceps deliveries performed without an episiotomy. The OASIS prevalence was approximately twofold higher in forceps compared to vacuum deliveries (aOR = 1.92, 95% CIs = 1.79-2.05). Performing either a mediolateral or lateral episiotomy was associated with a 45% decrease in the prevalence of OASIS relative to no episiotomy (aOR = 0.55, 95% CIs = 0.52-0.58). CONCLUSIONS: Opting for vacuum rather than forceps delivery in conjunction with a mediolateral or lateral episiotomy could significantly lower the OASIS prevalence in nulliparous women.

Perineoplasty for anal incontinence after obstetric anal sphincter injury repair: a case report.

BACKGROUND: The rectal and vaginal walls are typically sutured if severe perineal lacerations with rectal mucosal damage occur during vaginal delivery. In case of anal incontinence after the repair, re-suturing of the anal sphincter muscle is standard procedure. However, this procedure may not result in sufficient improvement of function. CASE PRESENTATION: A 41-year-old woman underwent suture repair of the vaginal and rectal walls for fourth-degree perineal laceration at delivery. She was referred to our department after complaining of flatus and fecal incontinence. Her Wexner score was 15 points. Examination revealed decreased anal tonus and weak contractions on the ventral side. We diagnosed anal incontinence due to sphincter dysfunction after repair of a perineal laceration at delivery. We subsequently performed sphincter re-suturing with perineoplasty to restructure the perineal body by suturing the fascia located lateral to the perineal body and running in a ventral-dorsal direction, which filled the space between the anus and vagina and increased anal tonus. One month after surgery, the symptoms of anal incontinence disappeared (the Wexner score lowered to 0 points), and the anorectal manometry values increased compared to the preoperative values. According to recent reports on the anatomy of the female perineal region, bulbospongiosus muscle in women does not move toward the midline to attach to the perineal body, as has been previously believed. Instead, it attaches to the ipsilateral surface of the external anal sphincter. We consider the fascia lateral to the perineal body to be the fascia of the bulbospongiosus muscle. CONCLUSIONS: In a case of postpartum anal incontinence due to sphincter dysfunction after repair of severe perineal laceration, perineoplasty with re-suturing an anal sphincter muscle resulted in improvement in anal sphincter function. Compared to conventional simple suture repair of the rectal wall only, this surgical technique may improve sphincter function to a greater degree.

Factors Associated with Obstetric Anal Sphincter Injury During Vacuum-Assisted Vaginal Delivery.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injury (OASI) is a major complication associated with vacuum-assisted vaginal delivery (VAVD). The aim of this study was to evaluate risk factors related to vacuum extraction that are associated with OASI. METHODS: This was a case-control study performed at a tertiary university teaching hospital. Included were patients aged 18-45 years who had a singleton pregnancy resulting in a live, term, VAVD. The study group consisted of women diagnosed with OASI following vacuum extraction. The control group included women following VAVD without OASI. Matching at a ratio of 1:2 was performed. Groups were compared regarding demographic, obstetric. and labor-related parameters, specifically focusing on variables related to the vacuum procedure itself. RESULTS: One hundred and ten patients within the study group and 212 within the control group were included in the final analysis. Patients in the OASI group were more likely to undergo induction of labor, use of oxytocin during labor, increased second stage of labor, higher likelihood of the operator being a resident, increased number of pulls, procedure lasting under 10 min, occipito-posterior head position at vacuum initiation, episiotomy, increased neonatal head circumference, and birthweight. Multivariate logistic regression analysis revealed that increased week of gestation (OR 1.67, 95% CI 1.25-2.22, p < 0.001), unsupervised resident performing the procedure (OR 4.63, 95% CI 2.17-9.90), p < 0.001), indication of VAVD being fetal distress (OR 2.72, 95% CI 1.04-7.10, p = 0.041), and length of procedure under 10 min (OR 4.75, 95% CI 1.53-14.68, p = 0.007) were associated with OASI. Increased maternal age was associated with lower risk of OASI (OR 0.9, 95% CI 0.84-0.98, p = 0.012). CONCLUSIONS: When performing VAVD, increased week of gestation, unsupervised resident performing the procedure, fetal distress as vacuum indication, and vacuum procedure under 10 min were associated with OASI. In contrast, increased maternal age was shown to be a protective factor.

Adjusting models to better predict obstetric anal sphincter injury (OASIS) in forceps-assisted vaginal deliveries: A retrospective cross-sectional trial.

OBJECTIVE: Obesity and maternal age are increasing among pregnant patients. The understood effect of body mass index (BMI), advanced maternal age (AMA), and second stage of labor on obstetric anal sphincter injury (OASIS) at delivery is varied. The objective of this study was to assess whether incorporating BMI, second stage of labor length, and AMA into a model for predicting OASIS among forceps-assisted vaginal deliveries (FAVD) had a higher predictivity value compared to models without these additions. METHOD: This was an IRB-approved retrospective cohort study of singleton gestations who underwent a FAVD between 2017 and 2021. The primary outcome was prediction of OASIS via established models versus models including the addition of new predictive factors. RESULTS: A total of 979 patients met inclusionary criteria and were included in the final analysis. 20.4% of patients had an OASIS laceration, 11.3% of neonates had NICU admissions, 23.7% had a composite all neonatal outcome, and 8% had a composite subgaleal/cephalohematoma outcome. Comparisons of known factors that predict OASIS (nulliparity, race, episiotomy status) to known factors with additional predictors (BMI, AMA, and length of second stage in labor) were explored. After comparing each model's AUC to one another (a total of 3 comparisons made), there was no statistically significant difference between the models (all P > 0.62). CONCLUSION: Including BMI, AMA, and second stage of labor length does not improve the predictivity of OASIS in patients with successful FAVD. These factors should not impact a provider's decision to perform a FAVD when solely considering increased odds of OASIS.

Is vaginal birth after cesarean section a risk factor for obstetric anal sphincter injury?

OBJECTIVE: To investigate whether women undergoing their first vaginal delivery after a previous cesarean section (secundiparous) are at increased risk for obstetric anal sphincter injury (OASI) compared with primiparous women. METHODS: A retrospective cohort study of 85 428 women who delivered vaginally over a 10-year period in a single tertiary medical center. Incidence of OASI, risk factors, and clinical characteristics were compared between primiparous women who delivered vaginally and secundiparous women who underwent their first vaginal birth after cesarean section (VBAC). A multivariable logistic regression analysis was used to study the association between VBAC and OASI. RESULTS: Overall, 36 250 primiparous and 1602 secundiparous women were enrolled, 309 of whom had OASI. The rates of OASI were similar among secundiparous women who had VBAC and primiparous women who underwent vaginal delivery (15 [0.94%] vs 294 [0.81%], P = 0.58). The proportions of third- and fourth-degree tears were also similar among secundiparous and primiparous women who experienced OASI (87% vs 91.5%, and 13% vs 8.5%, respectively, P = 0.68). Furthermore, the rates of OASI were similar in both study groups, although secundiparous women who underwent VBAC had higher rates of birth weights exceeding 3500 g (414 [25.8%] vs 8284 [22.8%], P = 0.016), and higher rates of vacuum-assisted deliveries (338 [21%] vs 6224 [17.2%], P < 0.001). A multivariate logistic regression analysis failed to establish a statistically significant association between VBAC and OASI (odds ratio 0.672, 95% confidence interval 0.281-1.61, P = 0.37). CONCLUSIONS: No increased risk for OASI was found in secundiparous women who underwent VBAC compared with primiparous women at their first vaginal birth.

Obstetric anal sphincter injury in the second birth after perineal wound complication in the first birth: A nationwide register cohort study.

OBJECTIVE: To investigate whether perineal wound complications in the first birth, alone or in conjunction with obstetric anal sphincter injury (OASI), is associated with an increased risk of OASI in the second birth. DESIGN: Nationwide population-based cohort study. SETTING: Sweden. POPULATION: Women (n = 411 317) with first and second singleton vaginal births in Sweden, 2001-2019. METHODS: Data on diagnostic codes and surgical procedures were retrieved from the Swedish Medical Birth Register and the Swedish Patient Register. A perineal wound complication was defined as wound infection, dehiscence or perineal haematoma within 2 months of childbirth. MAIN OUTCOME MEASURES: Associations between wound complications in the first birth and OASI in the second birth were investigated with logistic regression and presented as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs). RESULTS: In total, 2619 (0.6%) women had a wound complication in the first birth, and 5318 (1.3%) had an OASI in the second birth. Women with a wound complication but no OASI in the first birth had more than doubled odds of OASI in the second birth (aOR 2.73, 95% CI 2.11-3.53). Women with OASI and a wound complication in the first birth had almost tenfold odds (aOR 9.97, 95% CI 6.53-15.24) of recurrent OASI. CONCLUSIONS: Perineal wound complication in the first birth increases the likelihood of OASI in a subsequent birth.

Differences in rates of severe perineal trauma between midwife-led and obstetrician-led care in the Netherlands: A nationwide cohort study.

Objective: To investigate trends and rates of severe perineal trauma (SPT), also known as obstetric anal sphincter injury (OASI), between midwife-led and obstetrician-led care in the Netherlands, and factors associated with SPT. Methods: This nationwide cohort study included registry data from 2000 to 2019 (n = 2,169,950) of spontaneous vaginal births of term, live, cephalic, single infants, without a (previous) caesarean section or assisted vaginal birth.First, trends of SPT and episiotomy were shown. Second, differences in SPT rates between midwife- and obstetrician-led care were assessed. Third, associations of care factors with SPT were examined. Multivariable logistic regression analyses were used to determine which factors were important in the associations. All outcomes were stratified for parity. Results: Over time, the SPT incidence increased mainly in midwife-led care and episiotomy rates decreased. Compared to midwife-led care, SPT rates were lower in obstetrician-led care among primiparous women (aOR 0.78; 99 % CI 0.74-0.81) and comparable among multiparous women (aOR 1.04; 99 % CI 0.99-1.10). Among women without epidural analgesia, these differences were smaller for primiparous women (aOR 0.88; 99 % CI 0.84-0.92), but the SPT rate was higher in obstetrician-led care among multiparous women (aOR 1.09; 99 % CI 1.03-1.15). Among women without shoulder dystocia, induction, augmentation, and pain medication, SPT rates were comparable among primiparous women, but higher among multiparous women in obstetrician-led care. In midwife-led care, SPT occurred more often among hospital versus home births. In obstetrician-led care, lower SPT incidences were found among births with epidural analgesia and for multiparous women with induction or augmentation. Conclusions: Among spontaneous vaginal births, induction, augmentation, and epidural analgesia in obstetrician-led care may be an explanatory factor for the higher incidence of SPT among primiparous women in midwife-led care. More research is needed to explain differences in SPT rates and to understand how SPT can be prevented, while maintaining a high intact perineum rate.

Irritable bowel syndrome worsens faecal incontinence after primary repair of major obstetric anal sphincter injuries.

AIM: Obstetric anal sphincter injuries (OASIS) occur in approximately 3%-6% of vaginal deliveries and are the leading risk factor for late-onset faecal incontinence, which is an underdiagnosed pathology. The aim of this work was to use a validated scoring system to quantify the effect of irritable bowel syndrome (IBS) on the severity of faecal incontinence symptoms after primary repair of major OASIS (Grade IIIb-IV). METHOD: A prospective cohort study was performed on all women who underwent primary repair of major OASIS over a 6-year period. They were assessed with ultrasonography within 12 weeks. Two control groups (who did not have OASIS) were women who underwent elective caesarean section and primigravid women. Questionnaires were sent at least 12 months after delivery, or at first consultation for primigravids, which generated the main outcome measures: Cleveland Clinic faecal incontinence severity scores and the presence of IBS based on Rome III criteria. RESULTS: There was a total of 211 patients included in the three groups and the mean follow-up time was 26 months after sphincter repair. Ultrasonographic sphincter defects were detected in 37% but did not affect the faecal incontinence score (p = 0.47), except in patients with IBS. Within each group, patients with IBS had significantly worse faecal incontinence than those without. Women with both OASIS and IBS had the most severe faecal incontinence scores. CONCLUSION: OASIS has a limited negative effect on faecal incontinence, independent of whether residual ultrasonographic sphincter defects are present. However, the presence of IBS has a significant compounding effect on faecal incontinence in OASIS patients. The effect of IBS on faecal incontinence is also notable in caesarean section patients and primigravids, suggesting that IBS is an independent risk-factor that should have its place in predelivery assessment and counselling.

Is water delivery a good idea to prevent obstetric anal sphincter injuries in low risk primiparae? An exploratory study in a Swiss public teaching hospital.

OBJECTIVE: Obstetric anal sphincter injuries are feared perineal injuries that are associated with increased pelvic floor disorders. The knowledge of influencing factors as the mode of delivery is therefore important. The aim of this study is to compare the rate of obstetric anal sphincter injuries in primiparae after water and bed deliveries. STUDY DESIGN: In this retrospective cohort study 3907 primiparae gave birth in water or on a bed in a Swiss teaching hospital. The diagnosis of obstetric anal sphincter injuries was confirmed by a consultant of obstetrics and gynecology and treated by them. The rates of these injuries after water and bed births were compared. Subgroup analysis was performed to detect possible associative factors, such as birth weight, episiotomy, use of oxytocin in first and second stage of labor. RESULTS: 1844 (47.2 %) of the primiparae had a water delivery and 2063 (52.8 %) a bed delivery. 193 (4.94 %) were diagnosed with obstetric anal sphincter injuries, of which 68 (3.7 %) had a water delivery and 125 (6.1 %) a bed delivery, p < 0.001. Subgroup analysis revealed that, in the first and second stage of labor, the rate of obstetric anal sphincter injuries with oxytocin was significantly lower in water than in bed deliveries; p = 0.025, p < 0.017, respectively. The rate of obstetric anal sphincter injuries in the birth weight or episiotomy subgroups did not reach significance. CONCLUSIONS: In a teaching hospital setting with standardized labor management, primiparae with a water delivery have the lowest risk for obstetric anal sphincter injuries.

Family medicine physician identification of obstetric lacerations: a US national survey.

INTRODUCTION AND HYPOTHESIS: We evaluated family medicine obstetric providers' identification and categorization of vaginal delivery lacerations in the USA. We hypothesized that there would be inaccuracy in family medicine physicians' identification of vaginal delivery injuries, similar to our previous studies of midwives and obstetricians (OBs). METHODS: We included clinically active physicians who attended deliveries within 2 years and evaluated their identification and categorization of delivery lacerations using descriptive text and visual images. We asked about their education on this topic and how they document lacerations in the labor and delivery record. RESULTS: We analyzed 250 completed responses (70% of opened surveys). Fifty-five percent of respondents characterized their obstetric laceration training as "good" or "excellent" and half previously had education on obstetric lacerations. The median accuracy overall for the classification and identification of perineal lacerations was 78% (IQR 56-91%). Respondents frequently mischaracterized nonperineal lacerations. Few respondents (36%) reported using the third-degree injury subclassification system. In adjusted analysis, the highest scoring respondents were board certified in family medicine, with fewer years in practice, and a higher obstetric volume. CONCLUSIONS: Obstetric laceration diagnoses may be inaccurate, which could influence perinatal quality and patient outcomes. We found gaps in knowledge similar to previous reports on midwives and obstetricians in the USA. These data suggest a need for increased education and training on obstetric injuries, perhaps especially for physicians with less obstetric activity. Improved categorization and identification of vaginal delivery trauma can impact management and improve women's postpartum care and long-term pelvic floor outcomes.

UK survey of colorectal surgeons on the management of acute obstetric anal sphincter injuries.

AIM: The role of colorectal surgeons in the management of acute obstetric anal sphincter injury (OASI) is an ongoing debate. Their expertise in operating in the anorectal region lends itself to assisting in OASI repair. The aim of this study was to establish the current involvement and recommended management of acute OASI by colorectal surgeons. METHOD: An online survey of consultant colorectal surgeons was sent to members of the Pelvic Floor Society to assess current involvement in acute OASI management and repair. RESULTS: Forty completed surveys were collated and analysed. Sixty-five per cent of respondents had seen an acute OASI since being a consultant and 50% stated they were involved in the repair of OASI less than once per year. 37.5% felt that a de-functioning stoma was still necessary sometimes. Many agreed with current guidelines for OASI repair in terms of antibiotics, laxatives and follow-up. CONCLUSIONS: Colorectal surgeons have varied opinions on the management of OASI. We suggest that multidisciplinary training of obstetricians and colorectal surgeons could lead to more collaboration regarding the management of women with acute OASI.

In vivo measurement of the elastic properties of pelvic floor muscles in pregnancy using shear wave elastography.

OBJECTIVE: We aimed to investigate changes in the elastic properties of levator ani muscle (LAM) and external anal sphincter (EAS) during pregnancy using shear wave elastography (SWE). Our secondary objective was to examine the association between the elastic properties of pelvic floor muscles (PFM) and perineal tears at childbirth. METHODS: This was a prospective monocentric study, including nulliparous women. Three visits were planned (14-18, 24-28, and 34-38 weeks) with a SWE assessment of the LAM and EAS at rest and during Valsalva maneuver. Then, we collected data about the delivery's characteristics. Assessments were performed using an Aixplorer V12® device (SL 18-5 linear probe) using a transperineal approach, reporting the shear modulus in kPa. We looked for changes in PFM's elastic properties during pregnancy using one-way ANOVA for repeated measures. We compared the mean shear modulus in late pregnancy for each muscle and condition between women with an intact perineum at delivery and those with a perineal tear using Student's t test. RESULTS: Forty-seven women were considered. Forty-five women had vaginal delivery of which 38 (84.4%) had perineal tears. We did not report any significant changes in the elastic properties of PFM during pregnancy. Women with an intact perineum at delivery had a stiffer EAS at Valsalva maneuver in late pregnancy (27.0 kPa vs. 18.2 kPa; p < 0.005). CONCLUSIONS: There were no significant changes in the elastic properties of the PFM in pregnancy. Stiffer EAS in late pregnancy appears to be associated with a lower incidence of perineal tears.

Anal incontinence following obstetric anal sphincter injury: Is there a difference between subtypes? A systematic review.

AIMS: Obstetric anal sphincter injury (OASI) is associated with long-term anal incontinence (AI). We aimed to address the following questions: (a) are women with major OASI (grade 3c and 4) at higher risk of developing AI when compared to women with minor OASI (grade 3a and 3b)? (b) is a fourth-degree tear more likely to cause AI over a third-degree tear? METHODS: A systematic literature search from inception until September 2022. We considered prospective and retrospective cohort studies, cross-sectional and case-control studies without language restrictions. The quality was assessed by the Newcastle-Ottawa Scale and the Joanna Briggs Institute critical appraisal checklist. Risk ratios (RRs) were calculated to measure the effect of different grades of OASI. RESULTS: Out of 22 studies, 8 were prospective cohort, 8 were retrospective cohort, and 6 were cross-sectional studies. Length of follow-up ranged from 1 month to 23 years, with the majority of the reports (n = 16) analysing data within 12-months postpartum. Third-degree tears evaluated were 6454 versus 764 fourth-degree tears. The risk of bias was low in 3, medium in 14 and high in 5 studies, respectively. Prospective studies showed that major tears are associated with a twofold risk of AI for major tears versus minor tears, while retrospective studies consistently showed a risk of fecal incontinence (FI) which was two- to fourfold higher. Prospective studies showed a trend toward worsening AI symptoms for fourth-degree tears, but this failed to reach statistical significance. Cross-sectional studies with long-term (≥5 years) follow-up showed that women with fourth-degree tear were more likely to develop AI, with an RR ranging from 1.4 to 2.2. Out of 3, 2 retrospective studies showed similar findings, but the follow-up was significantly shorter (≤1 year). Contrasting results were noted for FI rates, as only 5 out of 10 studies supported an association between fourth-degree tear and FI. CONCLUSIONS: Most studies investigate bowel symptoms within few months from delivery. Data heterogeneity hindered a meaningful synthesis. Prospective cohort studies with adequate power and long-term follow-up should be performed to evaluate the risk of AI for each OASI subtype.

Re-evaluation of modifiable risk factors for obstetric anal sphincter injury in a real-world setting.

INTRODUCTION AND HYPOTHESIS: The objective was to identify modifiable risk factors for obstetric anal sphincter injury (OASI) in primiparous women. METHODS: This was a retrospective cohort study of primiparous women with a singleton vaginal delivery. Main outcome measures were incidence of OASI and odds ratios for possible risk factors: maternal age, body mass index and height, fetal birthweight and head circumference, gestational age, epidural analgesia, mediolateral episiotomy, and instrumental deliveries. Univariate and multivariate logistic regressions were performed using forward methods for variable selection. RESULTS: Of 19,786 primiparous women with a singleton vaginal delivery, 369 sustained an OASI (1.9%). Risk factors were identified: vacuum extraction (adjusted OR 2.06, 95% CI, 1.59-2.65, p < 0.001), increased fetal weight (aOR 1.06, 95% CI, 1.02-1.11, p = 0.002, per 100-g increments); head circumference (aOR 1.24, 95% CI, 1.13-1.35, p < 0.001, per 1-cm increments); gestational week (aOR 1.11, 95% CI, 1.02-1.2, p = 0.012, per week). Protective factors: mediolateral episiotomy (aOR 0.75, 95% CI, 0.59-0.94, p = 0.013) particularly in vacuum deliveries (aOR 0.50, 95% CI, 0.29-0.97, p = 0.040); epidural analgesia (aOR 0.64, 95% CI, 0.48-0.84, p = 0.001); maternal height ≥157 cm (aOR 0.97, 95% CI, 0.96-0.98, p = 0.006, risk decreases by 2.6% per 1 cm increase in height). CONCLUSIONS: Mediolateral episiotomy was protective against OASI in both spontaneous and instrumental deliveries of primiparae. Increased fetal weight and large fetal head circumference, particularly in short women, were significant risk factors. These findings support the performance of ultrasound to acquire updated fetal measures before admission to the labor ward.

Are we using best practice to guide laxative use in post-partum patients with obstetric anal sphincter injuries - A retrospective review.

OBJECTIVE: Obstetric anal sphincter injury (OASI) is the leading cause of anal incontinence (AI) in young women. Laxatives are recommended to enhance recovery, however there are no consistent guidelines to guide best practice on the type, frequency, and dose of laxative should be used. This study aimed to evaluate the current use of laxatives following repair of OASIs, and to determine any association with AI. Study design A retrospective cohort study of 356 women who sustained OASIs between January 2016 and June 2020, at a single tertiary centre in Adelaide. Data regarding the type, dose and frequency of laxatives prescribed was extracted from each patient. The degree of OASIs was determined by clinical examination and endoanal ultrasound, and AI was measured by the St Marks incontinence score. RESULTS: Multiple combinations and classes of laxatives were prescribed including bulking agent (Metamucil and Fybogel), emollients (Coloxyl), and osmotic laxatives (lactulose and Movicol). Bulking agents were prescribed for 245 women (68.8%), which is contrary to the current recommendations based on two previous randomised controlled trials. AI reported by 51 (14.3%) women. There were no statistical differences between AI and laxative type, dose, or frequency. CONCLUSION: Considerable variation existed in laxatives prescription. Bulking agents was not associated with higher rates of AI. Further research is required to improve post-partum care in women following repair of OASIs.

Diagnosis, management and training in perineal trauma: a UK national survey of obstetricians.

INTRODUCTION AND HYPOTHESIS: Perineal trauma during vaginal delivery is very common. Training in diagnosis and repair of trauma, including obstetric anal sphincter injuries, varies in the UK. We aimed to investigate the current knowledge and training received by obstetric physicians. METHODS: A national, validated survey was conducted online, using Qualtrics. The National Trainees Committee distributed the survey. It was also sent directly to consultants via email. RESULTS: A total of 302 physicians completed the survey and were included in the analysis. 3.9% of participants described their training in obstetric perineal trauma as "very poor" or "poor". 20.5% said they have not received training. 8.6% of physicians practising for more than 10 years had not had training for over 10 years. 70.5% responded "somewhat agree" or "strongly agree" when asked if they would like more training. Identification of first, second, third-, and fourth-degree tears from images and descriptions was very good (more than 80% correct for all categories). Classification of other perineal trauma was less consistent, with many incorrectly using the Sultan Classification. "Manual perineal support" and "Controlled or guided delivery" were the most frequently selected methods for the prevention of obstetric anal sphincter injury (OASI). CONCLUSIONS: Training experience for physicians in obstetric perineal trauma varies. Further improvement in training and education in perineal trauma, particularly in OASI, is needed for physicians. Perineal trauma that is not included in the Sultan Classification is often misclassified.