Predelivery sonographic predictors of obstetric anal sphincter injury among nulliparous women

OBJECTIVE

Data available at admission to delivery of nulliparous has rarely been investigated for prediction of obstetric anal sphincter injury (OASI). The aim of the present study was to study risk factors for OASI in nulliparous based on information available at admission.

METHODS

A retrospective study of all nulliparous women undergoing labor, during March 2011 to January 2021 was performed. We compared women with OASI following delivery to those without by univariate and multivariable regression.

RESULTS

A total of 30 262 deliveries were included and 4181 (13.4%) of those were delivered by an emergent cesarean delivery. OASI followed 453 (1.5%) deliveries. Women in the OASI group were younger 29 ± 4.4 versus 30 ± 4.8, P = 0.001. In a multivariable regression analysis, higher sonographic estimated fetal weight was positively associated with OASI occurrence (aOR, 95% CI: 1.13 [1.00-1.29]). Maternal age was inversely associated with OASI occurrence (adjusted odds ratio [aOR], 95% confidence interval [CI] 0.95 [0.92-0.97]).

CONCLUSION

Sonographic fetal weight estimation is an independent risk factor for OASI occurrence that may be available at admission for delivery among nulliparous women.

Recovery from Obstetric Anal Sphincter Injury in a Prospective Cohort of First Births

OBJECTIVE

 To identify risk factors for obstetric anal sphincter injuries (OASIS) for primiparous women who gave birth vaginally and to compare recovery by OASIS status in three domains as follows: (1) physical health and functioning, (2) mental health, and (3) healthcare utilization.

STUDY DESIGN

 This secondary analysis used data from 2,013 vaginal births in the First Baby Study, a prospective cohort study of women with first births between 2009 and 2011. Interview data at multiple time points were linked to birth certificate and hospital discharge data. The key exposure of interest was OASIS (3rd or 4th degree perineal laceration, identified in the hospital discharge data; n = 174) versus no OASIS (n = 1,839). We used multivariable logistic regression models to examine the association between OASIS and a range of outcomes including physical health and functioning, depression, and health care utilization, assessed at 1 month and 6 months postpartum.

RESULTS

 Eight percent of women had OASIS. In adjusted models, there were no differences in general physical health and functioning measures by OASIS (such as fatigue and overall self-rated health), but women with OASIS had higher rates of reporting perineal pain (p < 0.001), accidental stool loss (p = 0.001), and bowel problems (p < 0.001) at 1-month postpartum. By 6-month postpartum, there were no differences in reported physical health and functioning. There were no differences in probable depression at 1- or 6-month postpartum. Women with OASIS were more likely to attend a comprehensive postpartum visit, but there were no other differences in health care utilization by OASIS.

CONCLUSION

 Women with OASIS were at increased risk of accidental stool loss, bowel problems, and perineal pain in the immediate postpartum period. Women who had OASIS had similar physical functioning across a range of general health outcomes to women who gave birth vaginally without OASIS.

KEY POINTS

· Higher risk of bowel problems and accidental stool loss 1-month postpartum with OASIS.. · Higher risk of perineal pain 1-month postpartum with OASIS.. · No differences in health outcomes at 6-months postpartum by OASIS..

Obstetric risk factors for levator ani muscle avulsion: A systematic review and meta-analysis

OBJECTIVES

Women have a 11% lifetime risk of undergoing surgery for vaginal prolapse. Levator ani muscle (LAM) avulsion is one etiological factor associated with primary and recurrent pelvic organ prolapse. Pelvic organ prolapse has been shown to greatly affect the quality of life and well-being of women. Conduct a meta-analysis identifying risk factors associated with LAM avulsion recognised on transperineal ultrasound (TPUS) or magnetic resonance imaging (MRI) in primiparous women after vaginal birth.

STUDY DESIGN

OVID Medline, Embase and the Cochrane Library from inception to January 2021 were searched. Review Manager 5.3 (The Cochrane Collaboration) was used to analyse data. Odds ratios (OR) with 95% confidence intervals (95% CIs) were calculated. The heterogeneity among studies was calculated using the I2statistic.

RESULTS

Twenty-five studies were eligible for inclusion (n = 9333 women). Major LAM avulsion was diagnosed in an average of 22 % (range 12.7-39.5 %) of cases. Twenty-two studies used TPUS and three used MRI to diagnose avulsion. Modifiable and non-modifiable risk factors were identified. Significant predictors identified were forceps (OR 6.25 [4.33 - 9.0]), obstetric anal sphincter injuries (OR 3.93 [2.85-5.42]), vacuum (OR 2.41 [1.40-4.16]), and maternal age (OR 1.06 [1.02-1.10]).

CONCLUSIONS

This is the first meta-analysis of both modifiable and non-modifiable risk factors associated with LAM avulsion. This information could be used to develop a clinically applicable risk prediction model to target postnatal women at risk of LAM avulsion with a view to prevent the onset of pelvic floor organ prolapse.

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.

The postnatal effects of perineal trauma on maternal psychological and emotional wellbeing: A longitudinal study

OBJECTIVE

To examine the postnatal psychological health and parenting adjustment of primiparous women experiencing perineal trauma.

STUDY DESIGN

Longitudinal cohort study assessing body image, perceptions of traumatic birth, psychological distress, perineal pain, impact upon parental tasks and mother-infant bonding at 6-12 weeks (n = 103) and 6-10 months postnatally (n = 91). Primiparous women were recruited following vaginal birth and perineal suturing in a UK-based maternity hospital. al. Comparisons made according to the objective classification of perineal trauma experienced; 1st/2nd degree tear, episiotomy, and Obstetric Anal Sphincter Injuries (OASI).

RESULTS

At 6-12 weeks women with an episiotomy reported a more negative perception of their body image than those with OASI. Women with OASI or an episiotomy were more likely to have experienced birth as traumatic, and those with OASI reported more avoidance symptoms of post-traumatic stress and a greater negative impact on parenting tasks. At 6-10 months significantly more avoidance symptoms continued to be reported by those with OASI, whereas those with an episiotomy reported more anxiety related symptoms in general than those with OASI.

CONCLUSIONS

OASI, whilst associated with traumatic birth and some early parenting impacts, may not be linked to general negative psychological outcomes when specialist routine follow-up care is provided. Psychological impacts for women with episiotomy may merit further input than currently provided. Consideration should be given with regards to widening the access to postnatal perineal care by extending the criteria for specialist follow up beyond those sustaining OASI.

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.

The prevention of perineal trauma during vaginal birth

Perineal trauma after vaginal birth is common, with approximately 9 of 10 women being affected. Second-degree perineal tears are twice as likely to occur in primiparous births, with a incidence of 40%. The incidence of obstetrical anal sphincter injury is approximately 3%, with a significantly higher rate in primiparous than in multiparous women (6% vs 2%). Obstetrical anal sphincter injury is a significant risk factor for the development of anal incontinence, with approximately 10% of women developing symptoms within a year following vaginal birth. Obstetrical anal sphincter injuries have significant medicolegal implications and contribute greatly to healthcare costs. For example, in 2013 and 2014, the economic burden of obstetrical anal sphincter injuries in the United Kingdom ranged between £3.7 million (with assisted vaginal birth) and £9.8 million (with spontaneous vaginal birth). In the United States, complications associated with trauma to the perineum incurred costs of approximately $83 million between 2007 and 2011. It is therefore crucial to focus on improvements in clinical care to reduce this risk and minimize the development of perineal trauma, particularly obstetrical anal sphincter injuries. Identification of risk factors allows modification of obstetrical practice with the aim of reducing the rate of perineal trauma and its attendant associated morbidity. Risk factors associated with second-degree perineal trauma include increased fetal birthweight, operative vaginal birth, prolonged second stage of labor, maternal birth position, and advanced maternal age. With obstetrical anal sphincter injury, risk factors include induction of labor, augmentation of labor, epidural, increased fetal birthweight, fetal malposition (occiput posterior), midline episiotomy, operative vaginal birth, Asian ethnicity, and primiparity. Obstetrical practice can be modified both antenatally and intrapartum. The evidence suggests that in the antenatal period, perineal massage can be commenced in the third trimester of pregnancy to increase muscle elasticity and allow stretching of the perineum during birth, thereby reducing the risk of tearing or need for episiotomy. With regard to the intrapartum period, there is a growing body of evidence from the United Kingdom, Norway, and Denmark suggesting that the implementation of quality improvement initiatives including the training of clinicians in manual perineal protection and mediolateral episiotomy can reduce the incidence of obstetrical anal sphincter injury. With episiotomy, the International Federation of Gynecology and Obstetrics recommends restrictive rather than routine use of episiotomy. This is particularly the case with unassisted vaginal births. However, there is a role for episiotomy, specifically mediolateral or lateral, with assisted vaginal births. This is specifically the case with nulliparous vacuum and forceps births, given that the use of mediolateral or lateral episiotomy has been shown to significantly reduce the incidence of obstetrical anal sphincter injury in these groups by 43% and 68%, respectively. However, the complications associated with episiotomy including perineal pain, dyspareunia, and sexual dysfunction should be acknowledged. Despite considerable research, interventions for reducing the risk of perineal trauma remain a subject of controversy. In this review article, we present the available data on the prevention of perineal trauma by describing the risk factors associated with perineal trauma and interventions that can be implemented to prevent perineal trauma, in particular obstetrical anal sphincter injury.

Prevention of obstetric anal sphincter injuries with perineal support and lateral episiotomy: A historical cohort study

INTRODUCTION

There are many risk factors for obstetric anal sphincter injury (OASIS) and the interaction between these risk factors is complex and understudied. The many observational studies that have shown a reduction of OASIS rates after implementation of perineal support have short follow-up time. We aimed to study the effect of integration of active perineal support and lateral episiotomy on OASIS rates over a 15-year period and to study interactions between risk factors known before delivery.

MATERIAL AND METHODS

We performed a historical cohort study over the periods 1999-2006 and 2007-2021 at Stavanger University Hospital, Norway. The main outcome was OASIS rates. Women without a previous cesarean section and a live singleton fetus in cephalic presentation at term were eligible. The department implemented in 2007 the Finnish concept of active perineal protection, which includes support of perineum, control of fetal expulsion, good communication with the mother and observation of perineal stretching. The practice of mediolateral episiotomy was replaced with lateral episiotomy when indicated. We analyzed the OASIS rates in groups with and without episiotomy stratified for delivery mode, fetal position at delivery and for parity, and adjusted for possible confounders (maternal age, gestational age, oxytocin augmentation and epidural analgesia).

RESULTS

We observed a long-lasting reduction in OASIS rates from 4.9% to 1.9% and an increase in episiotomy rates from 14.4% to 21.8%. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with instrumental vaginal deliveries and occiput anterior (OA) position; 3.4% vs 10.1% (OR 0.31; 95% CI: 0.24-0.40) and 6.1 vs 13.9% (OR 0.40; 95% CI: 0.19-0.82) in women with occiput posterior (OP) position. Lateral episiotomy was also associated with lower OASIS rates in nulliparous women with spontaneous deliveries and OA position; 2.1% vs 3.2% (OR 0.62; 95% CI: 0.49-0.80). The possible confounders had little confounding effects on the risk of OASIS in groups with and without episiotomy.

CONCLUSIONS

We observed a long-lasting reduction in OASIS rates after implementation of preventive procedures. Lateral episiotomy was associated with lower OASIS rates in nulliparous women with an instrumental delivery. Special attention should be paid to deliveries with persistent OP position.

Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it?

Pelvic floor disorders after childbirth have distressing lifelong consequences for women, requiring more than 300,000 women to have surgery annually. This represents approximately 10% of the 3 million women who give birth vaginally each year. Vaginal birth is the largest modifiable risk factor for prolapse, the pelvic floor disorder most strongly associated with birth, and is an important contributor to stress incontinence. These disorders require 10 times as many operations as anal sphincter injuries. Imaging shows that injuries of the levator ani muscle, perineal body, and membrane occur in up to 19% of primiparous women. During birth, the levator muscle and birth canal tissues must stretch to more than 3 times their original length; it is this overstretching that is responsible for the muscle tear visible on imaging rather than compression or neuropathy. The injury is present in 55% of women with prolapse later in life, with an odds ratio of 7.3, compared with women with normal support. In addition, levator damage can affect other aspects of hiatal closure, such as the perineal body and membrane. These injuries are associated with an enlarged urogenital hiatus, now known as antedate prolapse, and with prolapse surgery failure. Risk factors for levator injury are multifactorial and include forceps delivery, occiput posterior birth, older maternal age, long second stage of labor, and birthweight of >4000 g. Delivery with a vacuum device is associated with reduced levator damage. Other steps that might logically reduce injuries include manual rotation from occiput posterior to occiput anterior, slow gradual delivery, perineal massage or compresses, and early induction of labor, but these require study to document protection. In addition, teaching women to avoid pushing against a contracted levator muscle would likely decrease injury risk by decreasing tension on the vulnerable muscle origin. Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery. It is only right that women be made aware of these risks during pregnancy. Educating women on the long-term pelvic floor sequelae of childbirth should be performed antenatally so that they can be empowered to make informed decisions about management decisions during labor.

[Evolution of the rate of episiotomies and obstetric anal sphincter injuries since the last recommendations of 2018]

OBJECTIVES

There is a progressive reduction in the rate of episiotomies since the recommendations of the French college of gynaecologists. Our objective was to study the evolution of the rate of episiotomies and Obstetric Anus Sphincter Injury (OASI) since the restriction of episiotomies in our department.

METHODS

Observational monocentric retrospective study performed at the Rouen University Hospital. The inclusion criteria were monofetal pregnancies, delivery at a term greater than or equal to 37 weeks of amenorrhea of a living, viable child and by cephalic presentation. We compared two periods corresponding to before and after the 2018 recommendations. We used logistic regression modelling to identify factors associated with the risk of episiotomies and of obstetrical anal injuries, overall and in case of instrumental delivery.

RESULTS

We included 3329 patients for the 1st period and 3492 for the 2nd period, and the rate of instrumental deliveries were respectively of 16.4% (n=547) and 17.9% (n=626). Multivariate analysis showed a significant decrease in the rate of episiotomies in the 2nd period (OR 0.14, CI 95% [0.12; 0.16], P<0.0001). Main factors associated with the risk of OASI were primiparity (OR 6.21, CI 95% [3.19; 12.11]) and the use of forceps (OR 4.23, CI 95% [2.17; 8.27]) overall; and instrumental delivery using forceps (OR 3.25, CI 95% [1.69; 6.22]) and delivery during the 2nd period (OR 1.98, CI 95% [1.01; 3.88]) in case of instrumental delivery.

CONCLUSIONS

Our study confirms that the voluntary reduction in the episiotomy rate does not seem to be associated with an increased risk of OASI, overall and in case of instrumental delivery. However, we show an increase in the rate of OASI in case of instrumental delivery since the latest recommendations.

A systematic review and a meta-analysis on the incidence of obstetric anal sphincter injuries during vaginal delivery

AIM

The incidence of obstetric anal sphincter injuries (OASIS) has increased in the past two decades despite improved awareness of the risk factors. This study aimed to define the incidence of OASIS in women with different features (instrumental delivery or other variables).

METHODS

A systematic review was conducted on articles reporting the incidence of OASIS. This review aims to examine the association of instrumentation and OASIS by performing a formal systematic review of the published literature. Databases used for the research were MEDLINE, Embase, CINAHL and 'Maternity and infant care' databases.

RESULTS

Two independent reviewers screened the selected articles. 2326 duplicates were removed from the total of 4907 articles. The remaining 2581 articles were screened for title and abstract. 1913 articles were excluded due to irrelevance. The remaining 300 were screened as full text. Primiparity associated with the use of forceps were the features associated with the highest incidence of OASIS in the selected articles (19.4%). OASIS in all women had an overall incidence of 3.8%. The incidence of OASIS in all women by geographical region was the highest (6.5%) in North America.

CONCLUSIONS

There are various factors that impact on the incidence of OASIS and the combination of some of these, such as the use of forceps in primiparas, resulted in the highest incidence of OASIS. The lack of international consensus is limiting the improvements that can be done to reduce OASIS rates and improve best clinical practice.

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.

A biomechanical perspective on perineal injuries during childbirth

BACKGROUND AND OBJECTIVE

Childbirth trauma is a major health concern that affects millions of women worldwide. Severe degrees of perineal trauma, designated as obstetric anal sphincter injuries (OASIS), and levator ani muscle (LAM) injuries are associated with long-term morbidity. While significant research has been conducted on LAM avulsions, less attention has been given to perineal trauma and OASIS, which affect up to 90% and 11% of vaginal deliveries, respectively. Despite being widely discussed, childbirth trauma remains unpredictable. This work aims to enhance the modeling of the maternal musculature during childbirth, with a particular focus on understanding the mechanisms underlying the often overlooked perineal injuries.

METHODS

A geometrical model of the pelvic floor muscles (PFM) and perineum (including the perineal body, ischiocavernosus, bulbospongiosus, superficial and deep transverse perineal muscles) was created. The muscles were characterized by a transversely isotropic visco-hyperelastic constitutive model. Two simulations of vaginal delivery were conducted with the fetus in the vertex presentation and occipito-anterior position, with and without the perineum.

RESULTS

The simulation that considered the perineum exhibited higher stresses over an extended area of the PFM, which suggests that including additional structures can impact the obtained results. The maximum stretch of the urogenital hiatus was 2.94 and the maximum stress was 23.86 kPa. The perineal body reached a maximum stretch of 1.95, which was more pronounced near the urogenital hiatus, where perineal tears may occur. The external anal sphincter's transverse diameter decreased by 51% and the maximum principal stresses were observed in the area close to the perineal body, where OASIS can occur.

CONCLUSIONS

The present study emphasizes the importance of including most structures involved in vaginal delivery in its biomechanical analysis and represents another step further in the understanding of perineal injuries and OASIS. The superior region of the perineal body and its connection to the urogenital hiatus and anal sphincter have been identified as the most critical regions, highly susceptible to injury.

Anal trauma caused by bull-horn injury

BACKGROUND

Bullfighting festivals are commonly performed at Spain. Perineal trauma due to bull-horn injury is associated with high morbidity due to sphincteric associated lesions METHODS: We report a case of 37-year-old male patient with anal trauma due to a bull-horn injury involving the sphincter complex, treated in our Emergency department RESULTS: Urgent surgery was performed with primary sphincteroplasty, without performing a colostomy. The associated complication was a partial dehiscence of the surgical wound (Clavien-Dindo I). No transfusions, re-interventions or readmissions were registered. The degree of incontinence at discharge and after 12 month follow-up, according to the Wexner scale was 8 points and 2 points, respectively.

CONCLUSIONS

The main treatment of bull-horn injuries is extensive surgical debridement, antibiotic therapy, and lavage of the area. In cases involving the anal sphincter, primary sphincteroplasty is recommended. The modern trend does not include the systematic performance of a colostomy however, it has been described in cases with catastrophic wounds and urological lesions associated.

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.

Is an episiotomy always necessary during an operative vaginal delivery with vacuum? A longitudinal study

Objective: The use of episiotomy during operative vaginal birth (OVB) is rather debated among operators and in literature. It is also important to evaluate the indications for which episiotomy is performed. In fact, the consequences of an episiotomy can be invalidating for patients with long-lasting results. The aim of this study is the evaluation of the role of episiotomy during OVB with the vacuum extractor and its correlation with Obstetric Anal Sphincter Injuries (OASIs).Methods: On of 9165 vaginal births, a total of 498 OVB (5.4%) were enrolled in a longitudinal prospective observational study. The incidence of OASIs was evaluated in our population after OVB performed with the vacuum extractor, during which the execution of episiotomy was performed indicated by clinician in charge.Results: OASIs occurred in 4% of the patients (n = 20). Episiotomy was performed in 39% of them (n = 181). OASIs incidence was 6% (n = 17) in the No Episiotomy and 1.8% (n = 3) in Episiotomy group (p<.001). Performance of episiotomy during OVB determined a protective effect against OASIs (p = 0.025 in full cohort and p = 0.013 in the primiparous group). An expulsive phase under one hour was an almost significant protective factor (p = 0.052).Conclusions: The use of episiotomy during OVB was associated with much lower OASIs rates in nulliparous women with a vacuum extraction; OR 0.23 (CI 95% 0.07-0.81) p = 0.037 in nulliparous women and the number necessary to treat was 18 among nulliparous women to prevent 1 OASIs. A further risk factor that emerged from the analysis is a prolonged expulsive period, whereas fundal pressure does not seem to have a statistically significant influence.

Management of postpartum perineal wound complications

PURPOSE OF REVIEW

Perineal wound complications occur in up to 25% of postpartum patients. Wound complications are most common after obstetric anal sphincter injuries (OASIS) but can occur after any laceration. It is imperative that any provider caring for postpartum patients understand the best evidence-based practices to recognize and manage these complications. We present a review of the available literature on the management of postpartum perineal wound complications.

RECENT FINDINGS

There is a paucity of new publications on the management of postpartum perineal wound complications, despite an increased emphasis on postpartum recovery in women's health. The role of topical estrogen in healing of perineal wounds was investigated in a pilot study, demonstrating that granulation tissue does express estrogen receptors, and the use of estrogen increases cell proliferation. Progression of perineal wound healing by secondary intention was evaluated in an observational study. Wound healing was delayed in 30% of women, with the initial wound area, perimeter, bacterial colonization, and OASIS being associated with delayed healing.

SUMMARY

Evidence based practices on timing of follow-up, addressing wound care and analgesia, administrating antibiotics, timing secondary repair, and surgical technique all play a role in optimizing recovery and reducing morbidity in patients with postpartum perineal wound complications.

Trends in obstetric anal sphincter injury in spontaneous vaginal delivery versus operative vaginal delivery over a 10-year period: Lessons learned

OBJECTIVE

To evaluate trends in the incidence of women with obstetric anal sphincter injuries (OASIS) over a 10-year period comparing spontaneous vaginal delivery (SVD) and operative vaginal delivery (OVD).

METHODS

A retrospective study was performed in which all women who underwent vaginal delivery over a 10-year period (n = 86 242, 2009-2018) at the Rotunda Hospital were reviewed. The overall incidence of OASIS was compared with incidence rates stratified by parity and type of vaginal birth.

RESULTS

The 10-year vaginal delivery rate was 69% (n = 59 187) where 24 580 women (42%) were primiparous and 34 607 women (58%) were multiparous. SVD rate was 74% and OVD rate was 26%. The overall incidence of OASIS was 2.9%. The incidence of OASIS in OVD was 5.5% and the incidence in SVD was 2%. Of 498 multipara who sustained OASIS, 366 (73%) had an SVD without episiotomy compared with 14 (3%) who had an episiotomy. There was a significant reduction of OASIS over the 10-year period in primipara who had an OVD but no reduction in the other groups.

CONCLUSION

The primiparous OVD group had a significant reduction of OASIS. Continued education around perineal protection and episiotomy at SVD could positively impact further reduction in OASIS, particularly in the SVD groups.

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.

Management of levator ani avulsion: a systematic review and narrative synthesis

PURPOSE

Levator ani muscle (LAM) avulsion affects up to 35% of women. Unlike obstetric anal sphincter injury, LAM avulsion is not diagnosed immediately after vaginal delivery, however, has a profound impact on quality of life. The management of pelvic floor disorders is in growing demand yet the significance of LAM avulsion in the context of pelvic floor dysfunction (PFD) is poorly understood. This study collates information on success of treatment for LAM avulsion to establish the best options for management of women.

METHODS

MEDLINE®, MEDLINE® In-Process, EMBASE, PubMed, CINAHL and The Cochrane Library were searched for articles that evaluated the management techniques used to treat LAM avulsion. The protocol was registered with PROSPERO (CRD42021206427).

RESULTS

Natural healing of LAM avulsion occurs in 50% of women. Conservative measures, including pelvic floor exercises and pessary use are poorly studied. Pelvic floor muscle training for major LAM avulsions was of no benefit. Post-partum pessary use was only of benefit in the first three months for women. Surgeries for LAM avulsion are poorly researched but studies suggest they may provide benefit for 76-97% of patients.

CONCLUSIONS

Whilst some women with PFD secondary to LAM avulsion improve spontaneously, 50% continue to have pelvic floor symptoms 1 year following delivery. These symptoms result in a significant negative impact on quality of life, however, it is not clear whether conservative or surgical methods are helpful. There is a pressing need for research to find effective treatments and explore appropriate surgical repair techniques for women with LAM avulsion.

Obstetric anal sphincter injury (OASI) in the presence of an intact perineum

Obstetric anal sphincter injury (OASI) in the absence of concurrent injury to the perineal skin is not a common diagnosis. A primiparous woman delivered a healthy male infant by spontaneous vertex delivery. At time of delivery, a compound presentation of the fetal hand with the head was noted. Initial examination revealed a presumed second-degree tear; however, a small laceration above the anal verge was noted, which on exploration revealed a perineal injury through the anal sphincter complex. In the operating theatre, the perineal skin was incised to reveal a 3c OASI, which was repaired appropriately. While atypical OASI has been reported previously, this specific injury has never been described in detail in the literature. Awareness of atypical perineal injuries is needed and while careful perineal examination is required in all cases, this is especially important where the perineal skin appears intact to ensure appropriate diagnosis of any concurrent OASI.

Clinical, ultrasonographic, and functional outcomes after obstetric anal sphincter injury primary repair: A single-center experience

OBJECTIVE

To present clinical and instrumental sequelae after obstetric anal sphincter injuries (OASIS), evaluating correlations between intrapartum severity of lesions, postpartum symptoms, and sonographic and manometric findings; outcomes during subsequent deliveries were also evaluated.

METHODS

This retrospective study evaluated all consecutive women who sustained an OASIS between 2015 and 2020. Postpartum symptoms, anorectal manometry (ARM), and three-dimensional endoanal ultrasonography (3D-EAUS) were analyzed.

RESULTS

A total of 107 women underwent OASIS primary repair; 84 (78.5%) of them were asymptomatic after 1 month. The presence and severity of symptoms showed a great correlation with instrumental outcomes in terms of maximum resting pressure, squeeze pressure increment (SPI), circumferential extension of defect for both external anal sphincter (EAS) and internal anal sphincter (IAS), and EAS, IAS and total Starck scores. There was a significant correlation between ARM and 3D-EAUS findings, with the exception of SPI, for which the abnormalities were not predictable based on EAUS results.

CONCLUSION

Both ARM and EAUS findings after OASIS are directly related to each other, and associated with symptoms. These instrumental tools may be useful for OASIS assessment and counseling.

Sonographic postpartum anal sphincter defects and the association with pelvic floor pain and dyspareunia

INTRODUCTION

Pelvic floor pain and dyspareunia are both important entities of postpartum pelvic pain, often concomitant and associated with perineal tears during vaginal delivery. The association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia has not been fully established. We aimed to determine the prevalence of postpartum anal sphincter defects using three-dimensional endoanal ultrasonography (3D-EAUS) and evaluate their association with symptoms of pelvic floor pain and dyspareunia.

MATERIAL AND METHODS

This prospective cohort study followed 239 primiparas from birth to 12 months post delivery. Anal sphincters were assessed with 3D-EAUS 3 months postpartum, and self-reported pelvic floor function data were obtained using a web-based questionnaire distributed 1 year after delivery. Descriptive statistics were compared between the patients with and without sonographic defects, and the association between sonographic sphincter defects and outcomes were analyzed using logistic regression.

RESULTS

At 3 months postpartum, 48/239 (20%) patients had anal sphincter defects on 3D-EAUS, of which 43 (18%) were not clinically diagnosed with obstetric anal sphincter injury at the time of delivery. Patients with sonographic defects had higher fetal weight than those without defects, and a perineum <2 cm before the suture was a risk factor for defects (odds ratio [OR], 6.9). Patients with sonographic defects had a higher frequency of dyspareunia (OR, 2.4), and pelvic floor pain (OR, 2.3) than those without defects.

CONCLUSIONS

Our results suggest an association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia. A perineal height <2 cm, measured by bidigital palpation immediately postdelivery, was a risk factor for sonographic anal sphincter defect. We suggest offering pelvic floor sonography around 3 months postpartum to high- risk women to optimize diagnosis and treatment of perineal tears and include perineum <2 cm prior to primary repair as a proposed indication for postpartum follow-up sonography.

Predictive factors for obstetric anal sphincter injury in primiparous women: systematic review and meta-analysis

OBJECTIVES

The primary objective was to perform a systematic review of predictive factors for obstetric anal sphincter injury (OASI) occurrence at first vaginal delivery, with the diagnosis made by ultrasound (US-OASI). The secondary objective was to report on incidence rates of sonographic anal sphincter (AS) trauma, including trauma that was not clinically reported at childbirth, among the studies providing data for our primary objective.

METHODS

We conducted a systematic search of MEDLINE, EMBASE, Web of Science, CINAHL, The Cochrane Library and ClinicalTrials.gov databases. Both observational cohort studies and interventional trials were eligible for inclusion. Study eligibility was assessed independently by two authors. Random-effects meta-analyses were performed to pool effect estimates from studies reporting on similar predictive factors. Summary odds ratio (OR) or mean difference (MD) is reported with 95% CI. Heterogeneity was assessed using the I2 statistic. Methodological quality was assessed using the Quality in Prognosis Studies tool.

RESULTS

A total of 2805 records were screened and 21 met the inclusion criteria (16 prospective cohort studies, three retrospective cohort studies and two interventional non-randomized trials). Increasing gestational age at delivery (MD, 0.34 (95% CI, 0.04-0.64) weeks), shorter antepartum perineal body length (MD, -0.60 (95% CI, -1.09 to -0.11) cm), labor augmentation (OR, 1.81 (95% CI, 1.21-2.71)), instrumental delivery (OR, 2.13 (95% CI, 1.13-4.01)), in particular forceps extraction (OR, 3.56 (95% CI, 1.31-9.67)), shoulder dystocia (OR, 12.07 (95% CI, 1.06-137.60)), episiotomy use (OR, 1.85 (95% CI, 1.11-3.06)) and shorter episiotomy length (MD, -0.40 (95% CI, -0.75 to -0.05) cm) were associated with US-OASI. When pooling incidence rates, 26% (95% CI, 20-32%) of women who had a first vaginal delivery had US-OASI (20 studies; I2  = 88%). In studies reporting on both clinical and US-OASI rates, 20% (95% CI, 14-28%) of women had AS trauma on ultrasound that was not reported clinically at childbirth (16 studies; I2  = 90%). No differences were found in maternal age, body mass index, weight, subpubic arch angle, induction of labor, epidural analgesia, episiotomy angle, duration of first/second/active-second stages of labor, vacuum extraction, neonatal birth weight or head circumference between cases with and those without US-OASI. Antenatal perineal massage and use of an intrapartum pelvic floor muscle dilator did not affect the odds of US-OASI. Most (81%) studies were judged to be at high risk of bias in at least one domain and only four (19%) studies had an overall low risk of bias.

CONCLUSION

Given the ultrasound evidence of structural damage to the AS in 26% of women following a first vaginal delivery, clinicians should have a low threshold of suspicion for the condition. This systematic review identified several predictive factors for this. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Asian-white disparities in obstetric anal sphincter injury: Protocol for a systematic review and meta-analysis

BACKGROUND

Obstetric anal sphincter injury (OASI) describes severe injury to the perineum and perineum and perianal muscles following birth and occurs in 4.4% to 6.0% of vaginal births in Canada. Studies from high-income countries have identified an increased risk of OASI in individuals who identify as Asian race versus those who identify as white. This protocol outlines a systematic review and meta-analysis which aims to determine the incidence of OASI in individuals living in high-income countries who identify as Asian versus those of white race/ethnicity. We hypothesize that the pooled incidence of OASI will be higher in Asian versus white birthing individuals.

METHODS

We will search MEDLINE, OVID, Embase, Emcare and Cochrane databases from inception to 2022 for observational studies using keywords and controlled vocabulary terms related to race, ethnicity and OASI. Two reviewers will follow the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and Meta-analysis of Observational Studies (MOOSE) recommendations. Meta-analysis will be performed using RevMan for dichotomous data using the random effects model and the odds ratio (OR) as effect measure with a 95% confidence interval (CI). Subgroup analysis will be performed based on Asian subgroups (e.g., South Asian, Filipino, Chinese, Japanese individuals). Study quality assessment will be performed using The Joanna Briggs Institute Critical Appraisal tools.

DISCUSSION

The systematic review and meta-analysis that this protocol outlines will synthesize the extant literature to better estimate the rates of OASI in Asian and white populations in non-Asian, high-income settings and the relative risk of OASI between these two groups. This systematic summary of the evidence will inform the discrepancy in health outcomes experienced by Asian and white birthing individuals. If these findings suggest a disproportionate burden among Asians, they will be used to advocate for future studies to explore the causal mechanisms underlying this relationship, such as differential care provision, barriers to accessing care, and social and institutional racism. Ultimately, the findings of this review can be used to frame obstetric care guidelines and inform healthcare practices to ensure care that is equitable and accessible to diverse populations.

Correlation of anorectal symptoms and endoanal ultrasound findings after obstetric anal sphincter injuries (OASIS)

INTRODUCTION

Obstetric anal sphincter injuries (OASIS) predispose to development of anorectal symptoms that affect women's quality of life.

METHODS

A retrospective cohort study was conducted for all women with singleton vaginal deliveries who had a primary OASIS repair and attended the Postpartum Perineal Clinic between July 1st 2017 and December 31st 2020. This study was approved by the Research Ethics Board. The purpose of this study was (1) to determine correlation between endoanal ultrasound (EAUS) findings and anorectal symptoms quantified by the St. Mark's Incontinence Score (SMIS), (2) to determine the incidence of residual anal sphincter defects, and (3) to determine the rate of clinical overdiagnosis of OASIS. Pearson correlation coefficient was used to assess correlation between anorectal symptoms and EAUS findings.

RESULTS

A total of 247 participants with clinical diagnosis of OASIS met the inclusion criteria. A 3rd-degree tear was identified in 126 (51.0%) and 4th-degree tear was identified in 30 (12.1%) participants. In participants with sonographic evidence of OASIS, there was a statistically significant weak positive correlation between the size of residual defect and SMIS for both external anal sphincter (EAS) (r = .3723, p < .0001) and internal anal sphincter (IAS) (r = .3122, p = .0180). Residual defect in the anorectal sphincter of greater than 1 hour (> 30°) in width was present in 64.3% participants with 3rd-degree tear and 86.7% participants with 4th-degree tear. The rate of overdiagnosis was 36.8%.

CONCLUSION

The size of residual defect of EAS and IAS has a weak positive correlation with anorectal symptoms, emphasizing the importance of EAUS for counselling regarding mode of subsequent delivery.

Risk indicators for obstetrical anal sphincter injury in vaginal birth after caesarean section compared to first vaginal delivery

OBJECTIVES

Comparison of the rate of obstetric anal sphincter injury (OASI) between women having their first vaginal birth after caesarean section (CS) and true nulliparous women with a vaginal delivery. Assessment of risk indicators for OASI in women with vaginal birth after one CS (VBAC).

STUDY DESIGN

28 535 women with their first VBAC and a cohort of 275 439 nulliparous women with a vaginal delivery of a liveborn infant in a cephalic position from the Dutch perinatal registry were analyzed. We compared the OASI rate with univariate and multivariate analysis. In women with VBAC possible risk indicators for OASI were assessed using univariate and multivariate logistic regression analysis.

RESULTS

The rate of OASI was 5.2% in women with vaginal birth after CS and 4.0% in women with a first vaginal delivery. The adjusted OR (aOR) for vaginal birth after an elective CS was higher (aOR 1.34, 95% CI 1.23-1.47) compared to vaginal birth after an emergency CS (aOR 1.16, 95% CI 1.08-1.25). In women with vaginal birth after emergency CS, the aOR for the indication non-progressive labor was 1.18 (95% CI 1.08-1.29), whereas CS for suspected fetal distress was not significantly associated with obstetric anal sphincter injury in VBAC. In the 28 535 women with a VBAC, mediolateral episiotomy (MLE), birth weight < 3000 g and maternal age < 25 years were associated with a significantly lower rate of OASI. A gestational age of 42 weeks, birth weight ≥ 3500 g, operative vaginal delivery and duration of the 2nd stage of labour of ≥ 60 min were associated with a significantly higher rate of OASI.

CONCLUSIONS

Women with a VBAC have a higher rate of OASI in comparison with women with a first vaginal delivery, with the exception of women with a vaginal birth after an emergency CS for suspected fetal distress. Factors associated with a significantly lower rate for OASI were MLE, maternal age < 25 and birth weight < 3000 g. A gestational age of 42 weeks, birth weight between 3500 and 4000 g and ≥ 4000 g, operative vaginal delivery and duration of the 2nd stage of delivery longer dan 60 min were associated with a significantly higher rate of OASI.

Assessing Obstetric Anal Sphincter Injuries: A Comparison of Exoanal and Endoanal Ultrasound

OBJECTIVES

To explore the differences in assessing obstetric anal sphincter injuries (OASI) between transperineal ultrasound (TPUS) and endoanal ultrasound (EAUS) and test relationships between ultrasound findings and anal incontinence (AI) symptoms.

METHODS

A group of 196 women with a history of vaginal delivery was recruited. OASI was detected in a set of 5 slices by EAUS and 8 slices by TPUS. OASI grading was performed on TPUS rules and EAUS rules. A "significant sphincter defect" was diagnosed by TPUS and EAUS using "2/3 rules." Symptoms of AI were determined using the St Mark's Incontinence Score (SMIS). Ultrasound findings were compared between the two methods and correlated with symptoms.

RESULTS

Of 196 women, 29 (14.8%) suffered from AI with a mean SMIS of 12.1 ± 4.5, and 70 (35.7%) women with a mean age of 57 years had suspected OASI on imaging. Twenty-one (10.7%) "significant defects" were diagnosed by TPUS and 24 (12.2%) by EAUS. OASI Grades on TPUS had good agreement with EAUS rules (k = 0.70, P < .001). Logistic regression analysis showed that OASI Grade on imaging and "significant sphincter defects" seen on both forms of imaging were associated with AI symptoms. The odds ratio was 46 and 38 for "significant defects" on TPUS and EAUS, and 14 and 7 for OASI 3b+ on TPUS and EAUS in predicting AI, respectively.

CONCLUSIONS

"Significant defects" diagnosed by EAUS or TPUS and OASI Grade 3b+ predict AI symptoms. The diagnostic performance of endoanal and exoanal ultrasound (EAUS and TPUS) appear to be very similar.

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.

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.

Neonatal head circumference as a risk factor for obstetric anal sphincter injuries: a systematic review and meta-analysis

OBJECTIVE

Between 53% and 79% of women will sustain some degree of perineal laceration during vaginal delivery. Third- and fourth-degree perineal lacerations are known as obstetric anal sphincter injuries. Timely diagnosis and prompt treatment of obstetric anal sphincter injuries can help to prevent the development of severe consequences like fecal incontinence, urinary incontinence, and rectovaginal fistula. Neonatal head circumference is routinely measured postpartum but is often not mentioned as a risk factor for obstetric anal sphincter injuries in clinical guidelines. Thus far, no review article on the risk factors for obstetric anal sphincter injuries has discussed the role of neonatal head circumference. This study aimed to review and analyze the relationship between head circumference and the occurrence of obstetric anal sphincter injuries among previous studies to conclude whether head circumference should be recognized as an important risk factor.

DATA SOURCES

Through study screening on Google Scholar, PubMed, Scopus, and Science Direct for articles published between 2013 to 2023, followed by assessment of eligibility, this study ended up reviewing 25 studies, 17 of which were included in the meta-analysis.

STUDY ELIGIBILITY CRITERIA

Only studies that reported both the neonatal head circumference and the occurrence of obstetric anal sphincter injuries were included in this review.

METHODS

The included studies were appraised using the Dartmouth Library risk of bias assessment checklist. Qualitative synthesis was based on the study population, findings, adjusted confounding factors, and suggested causative links in each study. Quantitative synthesis was conducted using calculation and pooling of odds ratios and inverse variance using Review Manager 5.4.1.

RESULTS

A statistically significant association between head circumference and obstetric anal sphincter injuries was reported in 21 of 25 studies; 4 studies reported that head circumference was a true independent risk factor. A meta-analysis of the studies that reported neonatal head circumference as a dichotomous categorical variable with a cutoff point of 35±1 cm yielded statistically significant pooled results (odds ratio, 1.92; 95% confidence interval, 1.80-2.04).

CONCLUSION

The risk for obstetric anal sphincter injuries increased as the neonatal head circumference increased-this should be considered in decision-making during labor and postpartum management to attain the best outcome.

The incidence of anal incontinence following obstetric anal sphincter injury graded using the Sultan classification: a network meta-analysis

OBJECTIVE

This study aimed to systematically determine and compare the incidence of anal incontinence between those with different grades of obstetric anal sphincter injury.

DATA SOURCES

Ovid MEDLINE, Embase, and the Cochrane Library were searched from January 2000 to April 2021.

STUDY ELIGIBILITY CRITERIA

Observational studies investigating the incidence of anal incontinence following an obstetric anal sphincter injury that was graded using the Sultan classification were eligible for inclusion. To allow comparison between individual tear grades (3a, 3b, 3c, fourth), a network meta-analysis was performed using Stata (version 15.1).

METHODS

For binary outcomes, odds ratios with corresponding 95% confidence intervals were reported. Obstetric anal sphincter injury grades were ranked from the best clinical outcome to the worst clinical outcome. The percentage chance of each grade taking each rank with regards to outcome was calculated. Study quality and risk of bias was assessed using the relevant tool from the Joanna Briggs Institute.

RESULTS

Of the 696 studies identified, 10 were eligible for inclusion and were included in the network meta-analysis (n=2467 women). The mean incidence of anal incontinence among those with 3a tears was 22.4% (range, 6.1%-51.2%), 24.9% (range, 6.9%-46.7%) among those with 3b tears, 26.8% (range, 0%-55.6%) among those with 3c tears, and 28.6% (0%-71.4%) among those with fourth-degree tears. Anal incontinence incidence was found to be significantly higher among those with 3c (odds ratio, 1.79; 95% confidence interval, 1.09-2.94) and fourth-degree tears (odds ratio, 2.37; 95% confidence interval, 1.40-4.02) than among those with 3a tears. In addition, anal incontinence incidence was significantly higher among those with fourth-degree tears (odds ratio, 1.89; 95% confidence interval, 1.10-3.22) than among those with 3b tears. Those with 3a tears had the highest probability of having the best clinical outcome; those with 3b; second-, 3c; third- and fourth-degree tears had the highest probability of having the worst clinical outcome. Overall, all studies had a high or unclear risk of bias across 1 or more assessed element.

CONCLUSION

This was a network meta-analysis comparing the incidence of anal incontinence among those with different grades of obstetric anal sphincter injury. Increasing tear-grade severity is associated with worse clinical outcomes. This study provides useful, clinically applicable information that can assist clinicians in the counseling of women following an obstetric anal sphincter injury. In addition, it highlights the importance of accurately diagnosing the obstetric anal sphincter injury grade and subsequently performing the appropriate repair.

Assessment of Perineal Scars on Translabial Pelvic Floor Ultrasound: A Pilot Study

OBJECTIVE

We aimed to describe a method for identifying and evaluating perineal scars using translabial pelvic floor ultrasound. We hypothesized that translabial ultrasound can identify a perineal scar and can differentiate episiotomies from spontaneous tears.

METHODS

This pilot study is a secondary analysis of data obtained in the Epi-No® trial. Perineal integrity was assessed using volumes acquired on pelvic floor muscle contraction according to the method previously described for anal sphincter imaging. A scar was diagnosed if a hypoechoic distortion in the perineum was noted. We postulated that an episiotomy would result in a linear scar visible on four dimensional translabial ultrasound whereas nonlinear scars were considered the result of spontaneous perineal tear of grade 2 or higher. The results of this assessment were compared with data retrieved from electronic medical records.

RESULTS

A scar was identified in 79/120 women (66%): 42 (35%) linear and 37 (31%) nonlinear. Sonographic and clinical diagnosis agreed on the presence or absence of perineal trauma in 66%. Agreement for the type of laceration was 50%.

CONCLUSION

In this retrospective pilot study, a blinded assessment of translabial ultrasound volume data showed agreement between clinical data and sonographic assessment of perineal integrity in 66% and of type of laceration in 50%. More work is needed to optimize the method in assessment of perineal scars to improve its performance before it can be used in clinical audit and research.

Universal Urogynecologic Consultation and Screening for Fecal Incontinence in Pregnant Women With a History of Obstetric Anal Sphincter Injury: A Cost-Effectiveness Analysis

IMPORTANCE

Obstetric anal sphincter injuries (OASIS) predispose for the development of fecal incontinence (FI), but management of subsequent pregnancy after OASIS is controversial.

OBJECTIVE

We aimed to determine if universal urogynecologic consultation (UUC) for pregnant women with prior OASIS is cost-effective.

STUDY DESIGN

We performed a cost-effectiveness analysis of pregnant women with a history of OASIS modeling UUC compared with no referral (usual care). We modeled the route of delivery, peripartum complications, and subsequent treatment options for FI. Probabilities and utilities were obtained from published literature. Costs using a third-party payer perspective were gathered from the Medicare physician fee schedule reimbursement data or published literature converted to 2019 U.S. dollars. Cost-effectiveness was determined using incremental cost-effectiveness ratios).

RESULTS

Our model demonstrated that UUC for pregnant patients with prior OASIS was cost-effective. Compared with usual care, the incremental cost-effectiveness ratio for this strategy was $19,858.32 per quality-adjusted life-year, below the willingness to pay a threshold of $50,000/quality-adjusted life-year. Universal urogynecologic consultation reduced the ultimate rate of FI from 25.33% to 22.67% and reduced patients living with untreated FI from 17.36% to 1.49%. Universal urogynecologic consultation increased the use of physical therapy by 14.14%, whereas rates of sacral neuromodulation and sphincteroplasty increased by only 2.48% and 0.58%, respectively. Universal urogynecologic consultation reduced the rate of vaginal delivery from 97.26% to 72.42%, which in turn led to a 1.15% increase in peripartum maternal complications.

CONCLUSIONS

Universal urogynecologic consultation in women with a history of OASIS is a cost-effective strategy that decreases the overall incidence of FI, increases treatment utilization for FI, and only marginally increases the risk of maternal morbidity.

3T external phased-array magnetic resonance imaging in detection of obstetric anal sphincter lesions: a pilot study

BACKGROUND

Three-dimensional endoanal ultrasound (3D EAUS) has been the gold standard for detecting anal sphincter lesions in patients with a history of obstetric anal sphincter injury (OASI). Advances in imaging technologies have facilitated the detection of these lesions with external phased-array magnetic resonance imaging (MRI), which could offer an alternative imaging modality for the diagnosis of residual OASI (ROASI) in centers where 3D EAUS imaging is not available.

PURPOSE

To compare two diagnostic modalities: the 3D EAUS and 3T external phased-array MRI in the detection of residual anal sphincter lesions.

MATERIAL AND METHODS

A total of 24 women with a history of OASI were imaged with both 3D EAUS and 3T external phased-array MRI after primary repair of the injury. Intraclass correlation (ICC) and interrater reliability (IRR) values were calculated for the grade and circumference of the sphincter lesion. Sphincter lesions were graded according to the Sultan classification.

RESULTS

There was an almost perfect agreement between 3D EAUS and 3T external phased-array MRI in determining the extent of the sphincter lesions according to the Sultan classification (κ = 0.881; P < 0.001) and the circumference of the external anal sphincter defects, measured in degrees (κ = 0.896; P < 0.001).

CONCLUSION

The results of this study indicate that 3T external phased-array MRI and 3D EAUS yield comparable results in the diagnosis of ROASI. These findings suggest that 3T external phased-array MRI could serve as an alternative diagnostic modality to 3D EAUS in the diagnosis of ROASI.

Obstetric risk factors for anal sphincter trauma in a urogynecological population

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter tears are the single major modifiable risk factor for anal incontinence (AI) in women. We undertook a retrospective observational study in a tertiary urogynecology unit to describe the prevalence of sonographic anal sphincter defects in a urogynecological population and investigate obstetric risk factors.

METHODS

Files of women seen for investigation of pelvic floor disorders between January 2014 and May 2021 were reviewed. Sonographic defects of the external anal sphincter were analyzed using stored 4D ultrasound imaging data. Explanatory parameters were number of vaginal births, delivery mode, age at first vaginal birth, and birthweight of the first vaginally born baby.

RESULTS

Of 3,037 women seen during the inclusion period, data were missing in 219, leaving 2,818. AI was reported by 508 (18%), with a mean St Marks score of 11 (1-23) and a mean bother score of 5.9 (0-10). External sphincter defects were detected in 945 women (34%), with a "residual defect" in 343 (12%). The strongest risk factors for a residual defect were first vaginal birth and forceps, with higher-order multiparity adding risk. On multivariate analysis, forceps and vaginal parity >5 remained significant predictors, as opposed to age at first birth and birthweight of the firstborn.

CONCLUSIONS

In this observational study in urogynecological patients, 12% showed a residual EAS defect on imaging. The most obvious risk factors for the diagnosis of a residual defect on exo-anal imaging were the first vaginal birth and forceps, with higher-order vaginal parity conveying additional risk.

Antibiotic administration and wound complications after obstetric anal sphincter injuries

BACKGROUND

Obstetric anal sphincter injuries are associated with both short-term and long-term maternal morbidity. Antibiotic administration has been shown to decrease wound complications after obstetric anal sphincter injuries. However, the rate of antibiotic administration in a contemporary obstetrical population is not known.

OBJECTIVE

This study aimed to describe the rate of antibiotic administration for obstetric anal sphincter injuries, to characterize factors associated with antibiotic administration on the day of delivery among women with obstetric anal sphincter injuries, and to determine if there was an association between antibiotic administration and reduced wound complications.

STUDY DESIGN

This was a retrospective cohort study of women with a singleton vaginal birth complicated by obstetric anal sphincter injuries between 2016 and 2021 in a single healthcare system. Information about any antibiotic administration on the day of delivery was collected. Information on wound complications (determined by International Classification of Disease, 10th Revision, codes) that occurred within the first 6 months postpartum were available for patients who delivered at tertiary-care centers. Multivariable logistic regression analysis was used to identify factors associated with antibiotic administration and the association between antibiotics and wound complications.

RESULTS

During the study period, 1550 women met the inclusion criteria of whom 855 (55.2%) received antibiotics. Antibiotic administration was higher at tertiary-care hospitals than at community-based hospitals (68.7 vs 26.8%; P<.001). In the adjusted analysis, antibiotic administration was higher among women with a fourth-degree laceration (adjusted odds ratio, 2.72; 95% confidence interval, 1.69-4.37) and lower among women of Asian or Pacific Islander heritage (adjusted odds ratio, 0.88; 95% confidence interval, 0.80-0.97). At tertiary-care hospitals, 43 women (4.1%) had a wound complication, and more than 80% of those presented within the first 2 weeks postpartum. Antibiotic use was associated with reduced rates of wound complications (adjusted odds ratio, 0.34; 95% confidence interval, 0.13-0.91). All patients received a regimen with gram-positive bacterial coverage; there was no association between type of antibiotic regimen administered and wound complications.

CONCLUSION

Any antibiotic administration on the day of delivery was associated with a decreased rate of wound complications after obstetric anal sphincter injuries. However, only about half of the women with obstetric anal sphincter injuries received antibiotics. Optimizing antibiotic administration may help to reduce the risk of complications in this population.

Body mass index and complications after obstetric anal sphincter injury, 8 weeks postpartum

INTRODUCTION AND HYPOTHESIS

The impact of body mass index (BMI) on pelvic floor recovery after an obstetric anal sphincter injury (OASI) is unclear. The aim of this study was to evaluate the hypothesis that urinary incontinence (UI) and anal incontinence (AI) are more common in overweight and obese women than in normal-weight women 8 weeks postpartum in women with OASI.

METHODS

A population-based cohort study including 6,595 primiparous women, with an OASI, delivered between 2014 and 2019. Exposure and questionnaire data were retrieved from the Swedish Perineal Laceration Registry. Uni- and multivariate analyses were used to compare normal-weight (BMI ≤24.9, reference), overweight (25.0-29.9), and obese (≥ 30) women with regard to UI and AI at 8 weeks post-partum.

RESULTS

Multivariate analyses showed an increased risk for urinary incontinence (OR 1.54, 95% CI 1.27-1.87) among overweight women as well as among obese women (OR 1.72, 95% CI 1.32-2.24). In contrast to our hypothesis, both overweight women (OR 0.68, 95% CI 0.56-0.83) and obese women (OR 0.65, 95% CI 0.49-0.87) were at a decreased risk for any gas and/or faecal incontinence after adjustment to possible confounding factors. The absolute rate of AI was 40.1% among normal-weight women, 34.2% among overweight women, and 29.1% in the obese group.

CONCLUSIONS

Urinary incontinence is more common, whereas AI is less common among overweight and obese women than in primiparous women with a BMI <24.9, 8 weeks after an OASI. The new finding, that overweight women report less AI than normal-weight women, merits further study.

Validation of new ultrasound algorithm for estimating prevalence of anal sphincter trauma in a urogynecological population

OBJECTIVES

To estimate the prevalence of major perineal trauma in a urogynecological population, to test the predictive value of sonographic tear grading (Gillor algorithm) for anal incontinence (AI), AI bother score and St Mark's score, and to compare the predictive power of the Gillor algorithm with that of the residual-defect method.

METHODS

This was a retrospective study of 721 women attending a tertiary urogynecology unit between February 2019 and May 2021. All women underwent a standardized interview, including determination of St Mark's score and visual analog scale (VAS) bother score for AI, as well as exoanal (translabial) ultrasound with later offline analysis. Results were reported as the presence of a residual defect of the external anal sphincter (EAS), i.e. a discontinuity of ≥ 30° in ≥ 4/6 tomographic slices, and according to the Gillor algorithm (normal, Grade 3a, Grade 3b or Grade 3c/4).

RESULTS

Mean age at assessment was 57 (range, 19-93) years and mean body mass index was 30 (range, 17-57) kg/m² . Six hundred and thirty-six (88.2%) women were vaginally parous and 161 (22.3%) had undergone at least one forceps delivery. AI was reported by 186/721 (25.8%) women, with a median St Mark's score of 10 (interquartile range (IQR), 6-14) and a median VAS score of 6.3 (IQR, 3.9-10). EAS defects were detected in 261 (36.2%) women, with a residual defect diagnosed in 88 (12.2%). On sonographic grading according to the Gillor algorithm, we identified 532 (73.8%) women with a normal sphincter, 66 (9.2%) with Grade-3a tear, 87 (12.1%) with Grade-3b tear and 36 (5.0%) with Grade-3c/4 tear. In total, the Gillor algorithm classified 189 (26.2%) women as having suffered a major perineal tear. The two grading systems were in moderate agreement (κ, 0.537 (95% CI, 0.49-0.56); P < 0.001). There were weak, albeit significant, associations between EAS defects and measures of AI (P = 0.009 to P = 0.047), both for residual defect as well as the Gillor algorithm.

CONCLUSION

Neither the Gillor algorithm nor the residual-defect method of quantifying sphincter trauma on imaging is clearly superior in terms of predicting AI. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Imaging Characteristics of Episiotomy Scars on Translabial Ultrasound: An Observational Study

INTRODUCTION

Episiotomy has been purported to protect the anal sphincter from injury; efficacy is, however, disputed. Correct execution of episiotomy may have substantial implications. We aimed to describe the characteristics of episiotomy scars on translabial ultrasound (TLUS).

METHODS

In this retrospective observational study involving women after repair of obstetric anal sphincter injuries, 76 women with a history of episiotomy were analyzed. Episiotomy scars were assessed on tomographic ultrasound in the transverse plane using volumes acquired on pelvic floor muscle contraction. We measured scar length, depth, and angle relative to a vertical reference line. Episiotomy scars were described as 1) ipsilateral if they started on the same side as the direction of the episiotomy, 2) contralateral if on the opposite side, and 3) mediolateral if the scar began in the midline.

RESULTS

The mean scar angle was 50.5° (SD 14°; range 14.4°-79.3°) while mean scar length was 14.2 mm (SD 4.5; range 5.7-27.5 mm) and depth was 8.4 mm (SD 2.8, range 3.1-18.2 mm). Sixteen (21%) scars were located mediolateral while 32 (42%) were ipsilateral. In 28 (37%) women, the starting point of the episiotomy was located contralateral to the direction of the episiotomy.

CONCLUSION

In this pilot series, the mean angle of episiotomy scars was within the safe zone of 40° to 60°, however, in one-third of cases the cut may have been initially directed toward the sphincter, not away from it. This observation suggests that not all episiotomies are performed optimally.

When to assess residual anal sphincter defect after OASI by ultrasound

OBJECTIVES

Obstetrical anal sphincter injuries (OASIS) are complications of vaginal delivery. Unrepaired anal sphincter after delivery increases the risk of anal incontinence. The aim of our study is to search for residual defect after OASI repair by 4D introital ultrasound (US). We hypothesised that imaging prior to hospital discharge would show the same number of defects as assessment at 3 months.

STUDY DESIGN

This is a retrospective analysis of 138 patients with immediate repair after OASIS. Since 2009, we have been routinely inviting all our patients with OASIS to the perineal clinic for postoperative follow-up. We scheduled the first visit before discharge from hospital and followed up with a second visit after three months. During both visits, patients underwent transperineal 4D ultrasound examination. We provided examination while at rest and during contraction; volumes were saved for further evaluation.

RESULTS

Eighty-one patients (58.7%) completed both exams and were included in the analysis. Residual external anal sphincter defect was found in 17.3% at the first visit versus 13.6% at the second (delayed) visit. We were not able to assess the sphincter in 9.9% at early versus none in the delayed examination. In 9.9%, the residual defect was not confirmed by the second examination, and in 4.9% the residual defect was missed by the first examination.

CONCLUSIONS

In conclusion, we have found that a 3 month scan yields a smaller number of defects than a scan before discharge.