Outcomes and follow-up after obstetric anal sphincter injuries

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.

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.

Association between birth weight and head circumference and obstetric anal sphincter injury severity

OBJECTIVE

To identify risk factors for increasing severity of OASI and evaluate its possible correlation with two known risk factors-birth weight (BW) and neonatal head circumference (HC).

METHODS

We performed a retrospective cohort study at a university affiliated hospital between 2003 and 2019. We compared five groups of patients - according to presence and degree of perineal laceration - 3a, 3b, 3c and 4 and patients without OASI. Additionally, four parameters were defined to assess their relation to the severity of OASI: (1) BW ≥ 90th and HC < 90th percentiles; (2) BW < 90th and HC ≥ 90th percentile; (3) BW and HC ≥ 90th percentile and (4) BW and HC < 90th percentiles.

RESULTS

During the study period, 150,221 deliveries were evaluated. Parturients were allocated according to OASI severity - 455 patients had a 3rd (3a, 3b or 3c) or 4th degree perineal tear, while 110,966 patients had no OASI. Allocation to subgroups according to offspring anthropomorphic measures showed that as fetal size parameters increased, the rate of more severe tears increased, particularly in women delivering neonates with HC ≥ 90th percentile. Multinomial regression analysis was performed for each 3rd degree OASI subgroup. This analysis demonstrated the odds for OASI gradually increase with tear severity for BW ≥ 90th percentile and the combined BW and HC ≥ 90th percentile parameters, as compared with neonates with HC and BW < 90th percentile.

CONCLUSIONS

Birth weight and head circumference above the 90th percentile are correlated with increased degree of OASI severity.

Obstetric anal sphincter injury following previous vaginal delivery

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASI) is a debilitating complication of vaginal delivery. The aim of this study was to identify risk factors for OASI in women with a previous vaginal delivery. We further attempted to detect specific risk factors for severe OASI in this subgroup.

METHODS

We conducted a retrospective cohort study between 2003 and 2019. The study group included women who had a singleton, live, vertex, vaginal delivery at term and who also had at least one previous vaginal delivery. The control group included women with at least one previous vaginal delivery without OASI. General medical history, obstetric history, and ante-, intra- and post-partum data were collected and compared between groups.

RESULTS

Following implementation of the inclusion criteria, 79,176 women were included. Allocation to study groups was according to OASI occurrence: 135 patients (0.2%) had a third- or fourth-degree perineal tear, while 79,041 patients (99.8%) had no such injury. Multivariate analysis revealed that one previous vaginal delivery, birthweight ≥ 3900 g (90th percentile), vacuum-assisted vaginal delivery and episiotomy were associated with increased risk of OASI. Comparison of more severe OASI (3C and 4th-degree) cases to the control group showed similar results with the addition of prolonged second stage and younger age to risk factors associated with severe OASI while episiotomy was no longer significant.

CONCLUSION

In women with a previous vaginal delivery, one vs. two or more previous vaginal deliveries, increased birthweight, vacuum-assisted vaginal delivery and episiotomy are risk factors for OASI.

Surgical repair and follow-up of chronic 4th degree obstetric perineal tear (total perineal defect) in 2 centres in eastern Africa

Introduction and hypothesis

Fourth-degree perineal tear occurs in up to 0.2% of vaginal deliveries. In limited resource communities, women often deliver in local villages without facilities to repair obstetric anal sphincter injuries. These fourth-degree tears heal by secondary intention and result in total perineal defects. The aim of the study is to present medium-term follow-up of a large number of women following repair of chronic fourth-degree tear.

Methods

Repairs of chronic obstetric fourth-degree tears were undertaken during surgical camps at Kagando Hospital, Uganda and Selian Hospital, Tanzania, from December 2013 to October 2019. Women completed Cleveland Clinic Incontinence Scores (CCIS) on admission (face to face) and during the 7-year follow-up period (via telephone).

Results

Two hundred fourteen women had medical history and CCIS completed on admission. The mean age at presentation was 33.9 years and mean duration of the condition was 8.9 years. Over a third of women stated they suffered social abandonment because of the unrepaired fourth-degree tear. Nearly 45% of women suffered the tear during the first vaginal delivery. At 1-year follow-up, 87% of 101 women scored 0 (perfect continence) and 94% of 66 women had perfect continence at 2 years. Forty-one births occurred during the follow-up period (32 vaginal deliveries) with two recurrences of fourth-degree tear.

Conclusions

Follow-up in limited resource communities is challenging. Short- to medium-term results of women who had repair of total perineal defect (unrepaired fourth-degree obstetric tears) are encouraging.

Can ultrasound 10 days after obstetric anal sphincter injury predict anal incontinence at long-term follow-up?

INTRODUCTION AND HYPOTHESIS

The objective was to investigate whether endoanal ultrasound (EAUS) performed 10 days after a primary repaired obstetric anal sphincter injury (OASIS) can predict the severity of anal incontinence (AI) in the long term.

METHODS

This prospective cohort study included women with a primary repaired 3b-degree tear, 3c-degree tear or fourth-degree tear at Aarhus University Hospital, Denmark, from 1 September 2010 to 31 May 2011. Clinical assessment and EAUS were performed on day 2, day 10, and day 20 after delivery. Functional outcomes were assessed using a questionnaire at the time of all clinical visits and at the long-term follow-up, 7 years after delivery. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score.

RESULTS

Ninety-six out of 99 women consented to participate. Five women had a secondary sphincter repair and were subsequently excluded from follow-up. Fifty-seven women underwent both EAUS 10 days after delivery and answered the long-term follow-up questionnaire. Median follow-up time was 7.7 years (IQR 7.4-7.8). Mean Wexner score was 4.4 ± 4.8 10 days after delivery and 2.5 ± 2.8 at follow-up; thus, the Wexner score improved over time (p = 0.01). Ultrasound sphincter defects were found in 82.6% of the women. Mean Starck score was 3.0 ± 1.8. The risk of AI was 0% (95% CI 0.0-30.8) if the Starck score was 0. No correlation was found between the Starck score and the Wexner score at follow-up.

CONCLUSIONS

We found that performing EAUS in the puerperium following OASIS has limited value in predicting long-term AI.

Postpartum anal incontinence in women with and without obstetric anal sphincter injuries

INTRODUCTION AND HYPOTHESIS

Postpartum anal incontinence is common and distressing for women. We sought to look at the prevalence of anal incontinence in women who sustained obstetric anal sphincter injuries (OASI) compared with women who did not, and factors leading to these symptoms during the postpartum period.

METHODS

A total of 129 primiparous women sustaining OASI were compared with 131 women who did not (controls). They were contacted at approximately 6-10 weeks postpartum to obtain information on their symptoms of anal incontinence (AI). The data underwent univariate and multivariate analysis.

RESULTS

There was no difference in the prevalence of AI symptoms, occurring in 30% of women with OASI, and 23% of women without at 6-10 weeks postpartum; however, in women with high-grade tears the prevalence was 59%. Severe OASI (grade 3c and 4) was associated with an increased prevalence of both AI and severe AI, whereas forceps delivery and increasing maternal age were associated with an increased prevalence of severe AI only.

CONCLUSION

Women with less severe (grade 3a and 3b) OASI do not experience a higher prevalence of AI than women without OASI in the postpartum period. Higher grade (3c and 4) tears, forceps delivery and increasing maternal age are associated with higher rates of AI. These factors should be avoided where possible to reduce postpartum AI. All women should be warned of the 23-30% chance of experiencing some mild AI in this period. Whether these symptoms are transient or long-lasting requires further investigation.

Prospective comparison of obstetric anal sphincter injury incidence between an Asian and Western hospital

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASIS) rates are reported to be higher in Asian women living in Western countries than in those living in Asia, but the reasons for the differences remain unclear. The objectives of this study were for a single examiner to prospectively compare OASIS rates in primiparous Asian women in an Asian and Western birth unit and determine potential birth factors that may influence the possible difference in OASIS incidence.

METHODS

This was a prospective observational study based in Hong Kong, China, and Sydney, Australia, involving primiparous women > 36 weeks gestation of Asian descent undergoing vaginal delivery. A single examiner recorded basic patient demographics, observed all the deliveries at both sites, noting birthing techniques, and then examined the women, including a rectal examination, to determine OASIS incidence.

RESULTS

Seventy births in Hong Kong and 66 in Sydney were studied. The incidence of OASIS was 34% in Sydney and 10% in Hong Kong (p = 0.001). Birthweight, epidural rate, body mass index, and instrumental delivery were higher in Sydney. Episiotomy rates were higher in Hong Kong (59.2% vs. 82.9%; p = 0.007). When comparing OASIS with no-OASIS, perineal length (OR = 0.36, 95% CI 0.17 to 0.76, p = 0.004) and birthweight (OR = 1.14, 95% CI 1.00 to 1.30, p = 0.039) were independent risk factors for OASIS.

CONCLUSIONS

The incidence of OASIS in Asian women is significantly higher in a Western than in an Asian setting. In Asian women, perineal length and birthweight can affect the risk of OASIS at the time of vaginal delivery.

Outcomes of primary anal sphincter repair after obstetric injury and evaluation of a novel three-choice assessment

Background

The aim of the present study was to evaluate the subjective outcome of primary repair of obstetric anal sphincter injury (OASIS) at 6 months, the factors associated with the symptoms of anal incontinence (AI), and the role of a simple survey consisting in one question with three answer choices, combined with the Wexner incontinence score for the assessment of this patient population.

Methods

A retrospective cohort study was conducted on patients with third- or fourth-degree OASIS operated on between January 2007 and December 2013 inclusive at Tampere University Hospital, Finland. At 6 months, the patients were asked to report their Wexner’s score as well as the three-choice assessment regarding AI symptoms. Based on this assessment, the patients were divided into three groups: those, asymptomatic, those with mild symptoms who did not want further treatment and those with severe symptoms who were willing to undergo further evaluation and treatment.

Results

There were 325 patients (median age 30 years). A total of 310 patients answered the questionnaire. Of which, one hundred and ninety-eight (63.9%) patients were asymptomatic, 85 (27.4%) had mild AI, and 27 (8.7%) experienced severe symptoms. There was no statistical difference in the results between the two techniques used (overlapping vs. end-to-end), or the stage of specialization of the operating physician. Persistent symptoms were associated with instrumental vaginal delivery (OR 2.12, 95% CI 1.32–3.41), severity of the injury (OR 1.64, 95% CI 1.20–2.25), and increased maternal age (OR 1.07, 95% CI 1.02–1.13). The correlation between the three-choice symptom evaluation and the Wexner score was good (Spearman’s rho 0.82).

Conclusions

After 6 months, severe symptoms after OASIS repair were present in 9% of women and were more frequent in older women, women with high-degree tears and after instrumental vaginal delivery. A three-choice assessment of AI symptoms correlated well with the Wexner score and might be useful to triage patients who need further evaluation.

Mental health screening in women with severe pelvic organ prolapse, chronic fourth-degree obstetric tear and genital tract fistula in western Uganda

INTRODUCTION AND HYPOTHESIS

High levels of mental health dysfunction have been identified in women with genital tract fistula. The aim of this study was to use the General Health Questionnaire-28 (GHQ-28) to screen women in western Uganda with severe pelvic organ prolapse, chronic fourth-degree obstetric tear and genital tract fistula for risk of mental health dysfunction.

METHODS

Women undergoing surgery for severe pelvic organ prolapse, chronic fourth-degree obstetric tear, and genital tract fistula were interviewed using the GHQ-28 to screen for the risk of mental health dysfunction.

RESULTS

A total of 125 women completed the GHQ-28, including 22 with pelvic organ prolapse, 47 with fourth-degree obstetric tear, 21 with genital tract fistula, and 35 controls. Nearly all women with these serious gynaecological conditions were positive for the risk of mental health dysfunction. In the domain assessing symptoms of severe depression, women with fourth-degree obstetric tear and genital tract fistula scored higher than women with pelvic organ prolapse.

CONCLUSIONS

A significant risk of mental health dysfunction was identified in women with severe pelvic organ prolapse and chronic fourth-degree obstetric tear. These rates are similar to the high rates of mental health dysfunction in women with genital tract fistula. Identification and management of mental health dysfunction in women with these conditions should be a priority.

Outcomes following surgical repair using layered closure of unrepaired 4th degree perineal tear in rural western Uganda

INTRODUCTION

In many rural low-income countries, perineal tears at time of vaginal birth are not repaired at time of delivery. The aims of this study are to describe the surgical technique for management of the unrepaired 4th degree tear, performed without flaps, and short-term follow up on anal incontinence symptoms using a validated questionnaire.

METHODS

Women presenting to fistula camps in western Uganda with unrepaired 4th degree tears were interviewed using the Cleveland Clinic Continence Score. Interviews were undertaken pre-operatively, at 4-6 weeks post-operatively and 12 months following surgery. Repair of the 4th degree tear was performed in layers, with an overlapping anal sphincter repair and reconstruction of the perineal body, without flaps. All women were examined prior to discharge.

RESULTS

68 women completed pre-operative Cleveland Clinic Continence Scores. Prior to surgery, 59 % of women complained of daily incontinence to solid stools. Over 70 % of women complained of restriction to lifestyle due to the unrepaired 4th degree tear. About 50 % of the women are rejected by their husbands because of the condition. Only 1 woman had wound breakdown on Day 2. At 4 to 6 weeks follow-up, 61 women were contacted and all reported perfect continence.

CONCLUSION

This study highlights the hidden problem of unrepaired 4th degree tears in rural areas of low-income countries where most deliveries are undertaken in the village without professional health care workers. These tears have significant impact on quality of life and anal incontinence. Short-term outcomes following surgical repair using a layered closure are promising.

Does the Finnish intervention prevent obstetric anal sphincter injuries? A systematic review of the literature

OBJECTIVES

A rise in obstetric anal sphincter injuries (OASIS) has been observed and a preventive approach, originating in Finland, has been introduced in several European hospitals. The aim of this paper was to systematically evaluate the evidence behind the 'Finnish intervention'.

DESIGN

A systematic review of the literature conducted according to the Preferred Reporting for Systematic Reviews and Meta-analyses (PRISMA) guidelines.

OUTCOME MEASURES

The primary outcome was OASIS. Secondary outcomes were (perinatal): Apgar scores, pH and standard base excess in the umbilical cord, and (maternal): episiotomy, intact perineum, first and second-degree perineal lacerations, duration of second stage, birth position and women's perceptions/birth experiences.

METHODS

Multiple databases (Cochrane, Embase, Pubmed and SveMed) were systematically searched for studies published up to December 2014. Both randomised controlled trials and observational studies were eligible for inclusion. Studies were excluded if a full-text article was not available. Studies were evaluated by use of international reporting guidelines (eg, STROBE).

RESULTS

Overall, 1042 articles were screened and 65 retrieved for full-text evaluation. Seven studies, all observational and with a level of evidence at 2c or lower, were included and consistently reported a significant reduction in OASIS. All evaluated episiotomy and found a significant increase. Three studies evaluated perinatal outcomes and reported conflicting results. No study reported on other perineal outcomes, duration of the second stage, birth positions or women's perceptions.

CONCLUSIONS

A reduction in OASIS has been contributed to the Finnish intervention in seven observational studies, all with a low level of evidence. Knowledge about the potential perinatal and maternal side effects and women's perceptions of the intervention is extremely limited and the biological mechanisms underlying the Finnish intervention are not well documented. Studies with a high level of evidence are needed to assess the effects of the intervention before implementation in clinical settings can be recommended.

Is the risk of obstetric anal sphincter injuries increased in vaginal twin deliveries?

OBJECTIVE

Vaginal twin deliveries have a higher rate of intrapartum interventions. We aimed to determine whether these characteristics are associated with an increased rate of obstetric anal sphincter injuries compared with singleton.

STUDY DESIGN

Retrospective study of all twin pregnancies undergoing vaginal delivery trial was conducted from January 2000-September 2014. Sphincter injury rate compared with all concurrent singleton vaginal deliveries. Multivariable analysis was used to determine twin delivery association with sphincter injuries while adjusting for confounders.

RESULTS

About 717 eligible twin deliveries. Outcome was compared with 33 886 singleton deliveries. Twin pregnancies characterized by a higher rate of nulliparity (54.8% versus 49.5%, p = 0.005), labor induction (42.7% versus 29.1%, p < 0.001), and instrumental deliveries (27.5% versus 16.7%, p < 0.001), lower gestational (34.6 ± 3.3 versus 38.8 ± 2.3, p < 0.001), and lower birth weight. Total breech extraction was performed in 29.0% (208/717) of twin deliveries. Overall obstetric sphincter injury rate was significantly lower in the twins group (2.8% versus 4.4%, p = 0.03, OR = 0.6, 95% CI 0.4-0.9), due to lower rate of 3rd degree tears in twins versus singletons (2.2% versus 4.0%, p = 0.02), rate of 4th degree tears similar among the groups (0.6% versus 0.4%, p = 0.5). In multivariable analysis, sphincter injuries were associated with nulliparity (OR = 3.9, 95% CI 3.4-4.5), forceps (OR = 6.8, 95% CI 5.8-7.8), vacuum (OR = 2.9, 95% CI 2.5-3.3), earlier gestational age (OR = 0.2, 95% CI 0.1-0.3), episiotomy (OR = 0.8, 95% CI 0.7-0.9), and birth weight over 3500 g (OR = 1.8, 95% CI 1.6-2.0). However, the association between twins (versus singletons) deliveries and sphincter injuries was lost after adjustment for delivery gestational age (OR = 0.7, 95% CI 0.4-1.2).

CONCLUSION

Despite a higher rate of intrapartum interventions, the rate of sphincter injuries is lower in twins versus singleton deliveries, mainly due to a lower gestational age at delivery.