Overdiagnosis and rising rate of obstetric anal sphincter injuries (OASIS): time for reappraisal

Detection of obstetric anal sphincter injuries using machine learning-assisted impedance spectroscopy: a prospective, comparative, multicentre clinical study

To evaluate the clinical performance and safety of the ONIRY system for obstetric anal sphincter injuries (OASI) detection versus three-dimensional endoanal ultrasound (EAUS). A prospective, comparative, multicentre, international study. Poland, Czechia, Slovakia, and Spain. 152 women between the first moments up to 8 weeks after vaginal delivery. Participants underwent EAUS and were allocated to groups based on OASIS classification: A (no perineal tear), B (1st or 2nd degree tear), or C (3rd or 4th degree, anal sphincters affected). Electric impedance was measured in the anal canal using the ONIRY system. The primary endpoint was the diagnostic outcome of impedance spectroscopy versus EAUS. Adverse events were collected. Part II involved in silico modelling and 10-time 10-fold cross-validation for automated analysis. Accuracy, sensitivity, and specificity. 30 women were allocated to group A, 61 to group B, and 61 to group C. The diagnostic outcome was determined for 147 participants. The accuracy, sensitivity, and specificity of the ML-assisted impedance spectroscopy were 87.0 ± 0.5%, 90.6 ± 2.0%, and 84.6 ± 1.9%, respectively, compared with EAUS. After data cleaning, the performance metrics of the proposed final ML model for ONIRY were: 90.0 ± 0.4%, 90.0 ± 1.2%, and 90.0 ± 0.7%, respectively. No adverse device effects or deficiencies were observed. By enabling early identification of sphincter injuries, ML-assisted impedance spectroscopy facilitates timely diagnosis and intervention, potentially reducing long-term complications such as faecal incontinence. Its rapid, bedside application in obstetric settings supports immediate postpartum care, complementing digital rectal examination and optimizing clinical decision-making.

Beyond the numbers: Impact of obesity on obstetric anal sphincter injury (OASI) outcomes in women

OBJECTIVE

To compare the risk profiles, anatomical, and functional outcomes between obese and non-obese women who experienced obstetric anal sphincter injury (OASI).

METHODS

A retrospective electronic database study was conducted at Cork University Maternity Hospital (CUMH). Women with missing data/repairs conducted outside CUMH were excluded. Participants were categorized into obese (BMI ≥30 kg/m2) and non-obese (BMI <30 kg/m2) groups. Primary measure was a composite adverse outcome assessed 6 months post-delivery, including one or more of the following: resting pressure <40 mmHg, squeezing pressure <100 mmHg, defects in the internal and/or external anal sphincter. Statistical analyses were performed using SPSS version 28.

RESULTS

Among the 349 women included in the study, 285 (81.7%) had a BMI <30 kg/m2 and 64 (18.3%) had a BMI ≥30 kg/m2. Gestational diabetes was significantly higher in obese women. No significant differences were observed in newborn weight or mode of delivery. The majority of tears were classified as grade 3B in both groups. Attendance rates at the OASI clinic did not differ between the groups. Among those attending, no statistical differences were noted in manometry results, which were reduced in both groups. Rates of internal anal sphincter defects were lower in the obese group (7.0% vs 15.6%, P = 0.15) and external anal sphincter defects were significantly lower in obese women (0% vs 9.1%, P = 0.04). No difference was found in the rates of composite adverse outcomes between the groups.

CONCLUSION

Functional outcomes and manometry results did not differ, but non-obese women had higher rates of anatomical defects in OASI, requiring further study.

Reliability of clinical examination for the assessment of obstetric anal sphincter injuries. A comparative study with 3D endoanal ultrasonography

OBJECTIVE

Anal incontinence (AI) affects up to 40% of women who sustained obstetric anal sphincter injuries (OASIs) due to persistent defects after primary repair or undiagnosed lesions. Aim of our research was to assess the reliability of clinical assessment of OASIs at the delivery as compared to three-dimensional endoanal ultrasonography (3D-EAUS).

METHODS

An observational prospective study was conducted between December 2015 and December 2022. Consecutive women with clinically diagnosed OASIs at the delivery were evaluated by 3D-EAUS two months post-partum. The primary aim was to evaluate the agreement between clinical and ultrasonographic assessment. The secondary aim was to investigate the correlation between ultrasound findings (grade of OASIs and anterior thickness of the external anal sphincter - EAS) and the severity of AI symptoms.

RESULTS

One hundred and sixty women were enrolled, median age 33.6 years (range 19-44; IQR, 30-37). Ninety-eight (61 %) were primiparous and sixty-two (39 %) were multiparous. In one hundred and thirty-seven cases (86 %) there was a perfect agreement between the clinical and ultrasonographic classification of OASIs. Twenty-three women (14 %) were clinically over-staged (17 % of cases) or under-staged (83 % of cases). The agreement between clinical assessment and 3D-EAUS was higher for OASIs grade 3a and 4 than for OASIs grade 3b and 3c (Fisher's test, P < 0.001). Similar findings were found after controlling for age, time interval between clinical evaluation and 3D-EAUS, number of previous deliveries and EAS thickness (R-squared = 0.674). The median anterior thickness of the EAS was 10.4 mm (range 7.2-13.6). The thickness did not correlate to the severity of OASIs (P = 0.215) but it positively correlated with the severity of incontinence symptoms (P < 0.001).

CONCLUSION

The agreement between clinical and ultrasonographic assessment was high for grade 3a and 4 OASIs. In case of uncertainty, clinical evaluation tended to underestimate the severity of sphincter lesions. The anterior thickness of the EAS was positively correlated with the severity of incontinence symptoms.

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

Objective

To investigate trends and rates of severe perineal trauma (SPT), also known as obstetric anal sphincter injury (OASI), between midwife-led and obstetrician-led care in the Netherlands, and factors associated with SPT.

Methods

This nationwide cohort study included registry data from 2000 to 2019 (n = 2,169,950) of spontaneous vaginal births of term, live, cephalic, single infants, without a (previous) caesarean section or assisted vaginal birth.First, trends of SPT and episiotomy were shown. Second, differences in SPT rates between midwife- and obstetrician-led care were assessed. Third, associations of care factors with SPT were examined. Multivariable logistic regression analyses were used to determine which factors were important in the associations. All outcomes were stratified for parity.

Results

Over time, the SPT incidence increased mainly in midwife-led care and episiotomy rates decreased. Compared to midwife-led care, SPT rates were lower in obstetrician-led care among primiparous women (aOR 0.78; 99 % CI 0.74-0.81) and comparable among multiparous women (aOR 1.04; 99 % CI 0.99-1.10). Among women without epidural analgesia, these differences were smaller for primiparous women (aOR 0.88; 99 % CI 0.84-0.92), but the SPT rate was higher in obstetrician-led care among multiparous women (aOR 1.09; 99 % CI 1.03-1.15). Among women without shoulder dystocia, induction, augmentation, and pain medication, SPT rates were comparable among primiparous women, but higher among multiparous women in obstetrician-led care. In midwife-led care, SPT occurred more often among hospital versus home births. In obstetrician-led care, lower SPT incidences were found among births with epidural analgesia and for multiparous women with induction or augmentation.

Conclusions

Iinduction, augmentation, and epidural analgesia in obstetrician-led care may be an explanatory factor for the higher incidence of SPT among primiparous women in midwife-led care. More research is needed to explain differences in SPT rates and to understand how SPT can be prevented, while maintaining a high intact perineum rate.

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.

Evidence for overdiagnosis in noncancer conditions was assessed: a metaepidemiological study using the 'Fair Umpire' framework

OBJECTIVES

To evaluate the strength of the evidence for, and the extent of, overdiagnosis in noncancer conditions.

STUDY DESIGN AND SETTING

We systematically searched for studies investigating overdiagnosis in noncancer conditions. Using the 'Fair Umpire' framework to assess the evidence that cases diagnosed by one diagnostic strategy but not by another may be overdiagnosed, two reviewers independently identified whether a Fair Umpire-a disease-specific clinical outcome, a test result or risk factor that can determine whether an additional case does or does not have disease-was present. Disease-specific clinical outcomes provide the strongest evidence for overdiagnosis, follow-up or concurrent tests provide weaker evidence, and risk factors provide only weak evidence. Studies without a Fair Umpire provide the weakest evidence of overdiagnosis.

RESULTS

Of 132 studies, 47 (36%) did not include a Fair Umpire to adjudicate additional diagnoses. When present, the most common Umpire was a single test or risk factor (32% of studies), with disease-specific clinical outcome Umpires used in only 21% of studies. Estimates of overdiagnosis included 43-45% of screen-detected acute abdominal aneurysms, 54% of cases of acute kidney injury, and 77% of cases of oligohydramnios in pregnancy.

CONCLUSION

Much of the current evidence for overdiagnosis in noncancer conditions is weak. Application of the framework can guide development of robust studies to detect and estimate overdiagnosis in noncancer conditions, ultimately informing evidence-based policies to reduce it.

Predicting perineal trauma during childbirth using data from a general obstetric population

Background

Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population.

Methods

Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation.

Results

Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance.

Conclusions

Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

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.

Follow up of women after obstetric anal sphincter injuries (OASI)-What is the role of anorectal testing?

AIMS

To evaluate the benefit of performing anorectal studies on all women following primary obstetric anal sphincter injury (OASI) repair over performing them on symptomatic women only.

METHODS

Women who attended perineal clinic between 2007 and 2020 underwent symptom assessment and anorectal studies at 6 weeks and 6 months postpartum. Anorectal studies including endo anal ultrasound (EAUS) and anal manometry (AM) were performed. The anorectal studies of symptomatic women who were the case group, were compared with asymptomatic women who were the control group.

RESULTS

A total of 1348 women were seen in the perineal clinic over 13 years. A total of 454 (33.7%) women were symptomatic. A total of 894 (66.3%) women were asymptomatic. A total of 313 (35%) asymptomatic women had two abnormal anorectal studies, 274 (31%) had abnormal AM alone, and 86 (9.6%) had abnormal EAUS alone. A total of 221 (24.7%) asymptomatic women had normal anorectal studies.

CONCLUSION

Almost 70% of women were asymptomatic 6 months following primary OASI repair. Most had at least one abnormal anorectal study result. Selectively performing anorectal tests on symptomatic women would not identify asymptomatic women at risk of future faecal incontinence following further vaginal birth. Without anorectal study results, women would not receive accurate counseling about the risks of vaginal birth. Anorectal studies should be offered to all women following OASI where resources allow.

Implementation of Episcissors-60 for Prevention of Obstetric Anal Sphincter Injuries (OASIS) in a Centre with Low Episiotomy Rates

OBJECTIVE

The purpose of this study was to determine whether introduction of Episcissors-60 into a labour and birth unit would decrease the incidence of Obstetric Anal Sphincter Injuries (OASIS).

METHODS

A before-and-after quality improvement study was conducted between April 1, 2020 and March 31, 2021. All patients who had a vaginal delivery were included in this study. All healthcare providers who perform vaginal deliveries were offered an educational session. Episcissors-60 were then introduced into a labour and birth unit. The primary outcome measure was the change in incidence of OASIS before and after introduction of Episcissors-60. Secondary outcome measures were episiotomy rates before and after introduction of Episcissors-60, device-related adverse events, and provider satisfaction and feedback. Data was analyzed using chi-square tests, independent t-tests, and Mann-Whitney tests.

RESULTS

A total of 1383 vaginal deliveries occurred prior and 1254 vaginal deliveries after introduction of Episcissors-60. There was a decrease in the total OASIS rate from 7.37% of all vaginal deliveries prior to 5.37% after introduction of Episcissors-60 (P = .037). The episiotomy rate was 11.42% prior to and 9.97% after introduction of Episcissors-60 (P = .228). OASIS rate in women who had an episiotomy was 12.02% before and 13.60% after introduction of Episcissors-60 (P = .421).

CONCLUSION

Although introduction of Episcissors-60 was associated with a statistically significant decrease in total OASIS rate, there was no difference in OASIS rates within the subgroup that received an episiotomy. Therefore, reduction in the total OASIS rate in this study cannot be attributed to the use of Episcissors-60.

Underdiagnosis of internal anal sphincter trauma following vaginal delivery

OBJECTIVE

Damage to the anal sphincter during childbirth remains the leading cause of fecal incontinence in women. Defects in the internal (IAS) or external anal sphincter, alongside symptoms and sphincter tone, will generally dictate the suggested mode of delivery in any successive pregnancy. This study aimed to examine using endoanal ultrasonography the prevalence of IAS damage in women referred with Grade-3a or -3b obstetric anal sphincter injury (OASI) in a tertiary-referral perineal clinic.

METHODS

This was a retrospective observational study of all women referred to a tertiary-referral perineal clinic after primary repair of OASI (Grade 3a-c, 4) diagnosed for the first time following vaginal delivery between January 2016 and December 2019, inclusive. Women were assessed using the Wexner bowel continence questionnaire, digital examination of sphincter tone and endoanal ultrasound. Injuries in each sphincter were classified as a scar (≤ 30°) or defect (> 30-90° or > 90°) on endoanal imaging in the axial plane.

RESULTS

In total, 615 women were referred following primary repair of OASI. Sonographic evidence of damage to the IAS was seen in 9.1% (46/506) of women diagnosed with a Grade-3a/3b injury. In women referred with a Grade-3a/3b tear, symptom scores were statistically higher (P = 0.025) in those with an IAS defect > 30° compared to those with an intact or scarred IAS, although the median score was zero in both groups. The proportion of women in each group with severe symptoms (score > 9) was similar (2.6% vs 6.5%; P = 0.148). Among women referred with a Grade-3a/3b tear, sphincter tone was reduced more frequently in those with a defect of the IAS than in those with an intact or scarred IAS (52.2% vs 11.7%; odds ratio, 8.14 (95% CI, 4.26-15.67); P < 0.001). Regardless of the reason for referral, women with reduced sphincter tone on rectal examination were four times as likely to have had an IAS defect > 30° than were those with normal resting tone (risk ratio, 4.58 (95% CI, 3.25-6.45); P < 0.001).

CONCLUSIONS

One in 11 women diagnosed with a Grade-3a or -3b tear have evidence of damage to their IAS on endoanal ultrasound. Damage to this muscle is linked to fecal incontinence in women and can have a significant impact on the planning of any future deliveries. This study highlights the importance of established perineal clinics with access to ultrasound. Nonetheless, if reduced sphincter tone is felt on rectal examination, a clinician should have a high index of suspicion for an occult IAS injury. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Use of endoanal ultrasound in detecting obstetric anal sphincter injury immediately after birth

INTRODUCTION

Obstetric anal sphincter injury (OASI) complicates around 5% of deliveries in primiparas. The study objective was to assess the utility of three-dimensional endoanal ultrasonography (3D-EAUS) in the diagnosis of OASI.

MATERIAL AND METHODS

The present study was designed to mirror screening settings with an unselected cohort of nulliparous women. All enrolled patients underwent clinical examination of the perineum by the caregiver, and 3D-EAUS was conducted. Post-processing of ultrasonography volume data was performed by an experienced colorectal surgeon who was blinded to all other data. The sensitivity, specificity, negative predictive value, and positive predictive value of 3D-EAUS in the diagnosis of OASI was evaluated. The trial is registered at ISCRTN: 18006769.

RESULTS

A total of 680 scans were performed, of which 18.5% were judged as "non-assessable", resulting in 554 assessable recordings. Sphincter defects were observed in 12.8% of all assessable recordings on 3D-EAUS (n = 71). With clinical examination set as the reference standard, ultrasound sensitivity in the diagnosis of OASI was 30.4%, whereas its specificity was 87.9%. The negative predictive value was 96.7% and the positive predictive value was only 9.9%. Comments were left on 175 examinations, of which 74% referred to the management of the examination.

CONCLUSIONS

Using 3D-EAUS in a maternity ward is demanding because staff generally have little experience in endoanal ultrasound, which contributes to difficulties in obtaining good image quality. When 3D-EAUS is performed to mirror screening settings, it adds no convincing diagnostic power to clinical examination in the diagnosis of OASI.

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.

Predicting perineal trauma during childbirth using data from a general obstetric population

Background: Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population. Methods: Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation. Results: Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance. Conclusions: Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.

Anal endosonographic assessment of the accuracy of clinical diagnosis of obstetric anal sphincter injury

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injuries (OASIS) are a common cause of maternal morbidity with an overall incidence in the UK of 2.9% (range 0-8%). They can cause a range of physical symptoms and psychological distress. This study aims to assess the accuracy of clinical diagnosis of OASIS using endoanal ultrasound (EAUS) and the correlation between confirmed injury and change to anorectal physiology squeeze pressure and the incidence of bowel symptoms.

METHODS AND MATERIALS

Retrospective study of prospectively collected data from 1135 women who attended the Third- and Fourth-Degree Tears Clinic at our institution, 12 weeks post-delivery, between June 2008 and October 2019.

RESULTS

OASIS was confirmed in 876 (78.8%) women and 236 (21.3%) had no injury. Of the women who underwent anorectal physiology, 45.6% had a mean maximal resting pressure below the normal range and 68.8% had a mean incremental squeeze pressure below normal. Women with confirmed OASIS had significantly lower pressures (p < 0.001) than those without a confirmed sphincter injury. Three hundred ninety-three (34.8%) women reported bowel symptoms, with those with endosonographic evidence of injury more likely to develop flatus incontinence.

CONCLUSION

Of the women in this study with a suspected OASIS, 21.2% could be reassured that they did not have an injury. This information is useful for women considering future mode of delivery. Those with confirmed injury are more likely to complain of flatus incontinence and have reduced anal sphincter pressures.

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.

Can transperineal ultrasound improve the diagnosis of obstetric anal sphincter injuries?

INTRODUCTION AND HYPOTHESIS

Women with missed obstetric anal sphincter injuries (OASIs) are at an increased risk of anal incontinence. Our aim was to assess the accuracy of three-dimensional (3D) transperineal ultrasound (TPUS) compared with clinical examination for detecting OASIs.

METHODS

A cross-sectional study of women undergoing their first vaginal delivery. Perineal trauma was initially assessed by the doctor or midwife performing the delivery (accoucheur) and women were then re-examined by the trained research fellow (KW). A 3D TPUS was performed immediately after delivery before suturing to identify OASIs. The research fellow's clinical diagnosis was used as the reference standard. A power calculation determined that 216 women would be required for the study.

RESULTS

Two hundred and sixty-four women participated and 226 (86%) delivered vaginally. Twenty-one (9%) sustained OASIs. Six (29%) of these tears were missed by the accoucheur but were identified by the research fellow. TPUS identified 19 of the 21 (90.5%) OASIs. One percent (n = 2) had sonographic appearances of an anal sphincter defect that was not seen clinically. The positive and negative predictive value of TPUS to detect OASIs was 91% and 99% respectively. TPUS identified 91% of OASIs compared with 71% detected by the accoucheur, which was not statistically significant.

CONCLUSIONS

The detection rate of OASIs with TPUS and with the clinical findings of the accoucheur was similar. Given the training and financial implications needed for TPUS, attention needs to be focused on the training of midwives and doctors to identify anal sphincter injuries by clinical examination.

Detailed classification of second-degree perineal tears in the delivery ward: an inter-rater agreement study

INTRODUCTION

Second-degree perineal tears can vary widely as to the extent of trauma, which may be relevant for women's pelvic floor health postpartum. However, the short- and long-term consequences of second-degree perineal tears are poorly understood, likely due to the lack of a detailed classification system. Such a classification system for second-degree tears has been suggested but the inter-rater agreement has not yet been assessed. The aim of this study was to assess the inter-rater agreement of the already established classification system for perineal tears recommended by the Royal College of Obstetricians and Gynaecologists (RCOG classification) among midwives. Further, we aimed to assess the inter-rater agreement of a classification system that provides three sub-categories for second-degree perineal tears.

MATERIAL AND METHODS

This was an inter-rater agreement study, conducted at Akershus University Hospital in Norway from 31 August to 29 November 2020. All midwives working in the delivery ward participated in the study. Midwives classified the integrity of the perineum of all women delivering vaginally within the study period. During the first month of the study, tears were classified by two midwives who were blinded to each other's findings, and the agreement of the RCOG classification was assessed. The following month, the detailed classification system was introduced to the midwifery staff. The last month, perineal tears were classified by two midwives using the detailed classification system, and the agreement was assessed. Inter-rater agreement was measured using Fleiss multirater kappa (k) and Kendall's coefficient of concordance (KCC_w ).

RESULTS

The inter-rater agreement for the RCOG classification was good to very good, with k = 0.705 (95% confidence interval [CI] 0.62-0.79, P < 0.001), KCC_w  = 0.928 (P < 0.001). The inter-rater agreement for the detailed classification system was good to very good, with k = 0.748 (95% CI 0.67-0.83, P < 0.001), KCC_w  = 0.956 (P < 0.001).

CONCLUSIONS

The inter-rater agreement among midwives using both the RCOG classification and the detailed classification system among midwives was good to very good. The detailed classification system provides additional information about the extent of tissue trauma in second-degree tears, warranted for future research on women's pelvic floor health postpartum.

Is there a role for transperineal ultrasound imaging of the anal sphincter immediately after primary repair of third degree tears?

OBJECTIVE

When obstetric anal sphincter injuries are identified, it is crucial that the defects are repaired appropriately to achieve a better outcome. Although the presence of an intact anal sphincter is not the sole mechanism for maintaining continence, and not all women with an anal sphincter defect are symptomatic, there is an association between sphincter defects and anal incontinence. Our aim was to evaluate whether transperineal ultrasound (TPUS) is useful in assessing anal sphincter integrity immediately following primary repair of obstetric anal sphincter injuries (OASIs).

STUDY DESIGN

This is a prospective observational study of women who sustained OASIs during their first vaginal delivery. Three dimensional (3D) TPUS was performed immediately after repair of OASIs to identify anal sphincter defects. A repeat TPUS was performed 12 weeks following repair.

RESULTS

21 women sustained OASIs of whom 20 (95%) attended follow up. Eight (40%) had a grade 3a tear and 12 (60%) a 3b tear. 8/20 (40%) women had residual external anal sphincter (EAS) defects identified by TPUS immediately after repair. Of these eight defects, six (75%) persisted at 12 weeks postpartum. No new defects were seen at follow up among the twelve women in whom no defect was seen immediately following the repair. Six residual EAS defects were found at 12 weeks postpartum. An EAS defect at 12 weeks postpartum was associated with anal incontinence (p = 0.04). Women with 3b tears were more likely to have anal incontinence (AI) and residual sonographic EAS defects when compared with 3a tears but this was not statistically significant.

CONCLUSIONS

Women who had no TPUS defect detected immediately following primary repair of OASIs, remained as such at 12 weeks postpartum. Of those in whom a defect was seen immediately after repair, it persisted in 75% of cases at 12 weeks. We believe that the value of TPUS immediately after repair appears to be limited and would need to be defined if it were to be considered for routine practice. Further research on its role immediately after repair of major tears (Grade 3C/4) is needed. In addition, performing ultrasound would require widespread training of obstetricians to develop expertise. This highlights the importance of adequate training of obstetricians in OASI repair.

Under-classified obstetric anal sphincter injuries

INTRODUCTION AND HYPOSTHESIS

Obstetric anal sphincter injuries (OASIs) that are missed at delivery can have long-term consequences. OASIs that are under-classified at delivery are likely to be inadequately repaired, resulting in a persistent anal sphincter defect. We aimed to identify women who have persistent defects on endoanal ultrasound, inconsistent with the original diagnosis, and compare the effect on St Mark's incontinence scores (SMIS). We also aimed to look for changes in numbers of under-classification over time.

METHODS

Records of women attending a perineal clinic who had endoanal ultrasound from 2012 to 2020 were reviewed. Women who had a modified Starck score implying a defect greater than the classification [indicated by the depth of external anal sphincter or internal anal sphincter (IAS) defect] at delivery were identified.

RESULTS

A total of 1056 women with a diagnosis of 3a or 3b tears were included. Of these, 120 (11.36%) were found to have a defect greater than the original diagnosis and therefore were incorrectly classified at delivery. Women who had a 3b tear diagnosed at delivery, but had an IAS defect, had a significantly higher SMIS (p < 0.01). When comparing two 4-year periods, there was a significant improvement in the diagnosis of IAS tears.

CONCLUSION

Some women with OASIs that have under-classified OASIs are associated with worse anorectal symptoms. This is likely because of an incomplete repair. Some improvement in diagnosis of IAS tears has been noted. We propose improved training in OASIs can help reduce the number of incorrectly classified tears and improve repair.

Obstetric anal sphincter injuries and other delivery trauma: a US national survey of obstetrician-gynecologists

INTRODUCTION AND HYPOTHESIS

Obstetric lacerations complicate the majority of deliveries. The application of standardized guidelines for assessing delivery trauma has not been assessed thoroughly in the United States. We recently identified gaps in US midwives' clinical assessment of delivery trauma. We conducted a cross-sectional national survey of practicing obstetricians in the USA to characterize their classification of obstetric lacerations. We hypothesized that attending obstetricians' identification and diagnosis of delivery trauma would be similar to our findings for midwives with frequent inaccuracy.

METHODS

We recruited clinically active obstetricians through the Pregnancy-Related Care Research Network. We asked participants to classify (from written definitions) and diagnose (from standard illustrations) common forms of vaginal delivery trauma using the widely employed perineal laceration degree system. We performed bivariate analysis of high- and low-scoring respondents and logistic regression to model characteristics associated with higher diagnostic accuracy.

RESULTS

Of the 162 respondents who started the survey, 76% (123) were included for analysis (22% of solicited emails). Overall, we found wide variation in response accuracy with as few as 62% of respondents correctly classifying certain types of lacerations. Only 49 out of 123 (40%) use the Sultan third-degree subclassification system and 67 out of 123 (52%) continue to use the midline/median approach for episiotomies. Providers reporting fewer deliveries per month and fewer publicly insured patients earned higher scores.

CONCLUSIONS

Obstetricians in a nationally representative US perinatal provider network inconsistently identify perineal and nonperineal lacerations. We found important clinical knowledge gaps, suggesting that vaginal delivery diagnoses in obstetric quality studies and pelvic floor research might be inaccurate.

Postpartum ultrasound for the diagnosis of obstetrical anal sphincter injury

This review presents the available data on the diagnosis of obstetrical anal sphincter injury by postnatal ultrasound imaging. There is increasing evidence that anal sphincter tears are often missed after childbirth and, even when diagnosed, often suboptimally repaired, with a high rate of residual defects after reconstruction. Even after postpartum diagnosis and primary repair, 25% to 50% of patients will have persistent anal incontinence. As clinical diagnosis may fail in the detection and classification of obstetrical anal sphincter injury, the use of imaging has been proposed to improve the detection and treatment of these lacerations. Notably, 3-dimensional endoanal ultrasound is considered the gold standard in the detection of obstetrical anal sphincter injury, and recently, 4-dimensional transperineal ultrasound, commonly available in obstetrical and gynecologic settings, has proven to be effective as well. Avoidance of forceps delivery when possible, performance of a rectal examination after vaginal delivery and before repair of any severe perineal tear, and offering sonographic follow-up at 10 to 12 weeks after vaginal delivery in high-risk women (maternal age of ≥35 years, vaginal birth after cesarean delivery, forceps, prolonged second stage of labor, overt obstetrical anal sphincter injury, shoulder dystocia, and macrosomia) may help reduce morbidity arising from anal sphincter tears.

Effectiveness of structured education and training in perineal wound assessment and repair for midwives and midwifery students: A review of the literature

INTRODUCTION

Perineal trauma is a commonly observed complication of childbirth, affecting more than 75% of women who have a vaginal birth. Perineal trauma is associated with significant short- and long-term comorbidities that negatively impact women's quality of life. Severe perineal trauma (SPT) rates in Australia have almost doubled in the last decade. Reasons for increased rates are not completely understood; some researchers suggest improvements in diagnosis and reporting, while others have a view that it may be due to a lack of structured and standardized education in perineal wound assessment and repair for clinicians.

METHODS

The Joanna Briggs Institute (JBI) scoping review methodology was adopted as a systemic process to identify studies that have investigated the effectiveness of perineal wound assessment and repair education and training for midwives and midwifery students.

RESULTS

Five studies met the inclusion criteria for this review, to have evaluated a type of education or training, on childbirth-related perineal wound assessment and repair that included midwives and midwifery students. A total of 1279 midwives and midwifery students volunteered to participate in all five studies. The length of the education or training implemented varied between each study from a 1-day workshop to 100 hours of education. All five studies measured the effectiveness of each program through changes in participants' confidence, knowledge and skills in perineal assessment and repair before and after an intervention using various self-assessment questionnaires.

CONCLUSIONS

The implementation of a structured educational workshop on perineal wound assessment and repair improves the confidence, skills and knowledge of midwives and students.

Residual Defects of the Anal Sphincter Complex Following Primary Repair of Obstetrical Anal Sphincter Injuries at a Large Canadian Obstetrical Centre

OBJECTIVES

To determine the rates of residual anal sphincter defect following primary repair of obstetrical anal sphincter injury (OASIS), and to assess symptomatology in these patients.

METHODS

A retrospective observational study of patients who underwent primary repair of an OASIS sustained at Mount Sinai Hospital from January 2016 to June 2017. Records were reviewed for demographic and obstetrical data, symptoms of anal incontinence (AI), and the results of endoanal ultrasonography (EA-US).

RESULTS

One hundred and one women sustained an OASIS during the study period, of whom 53 had EA-US performed at Mount Sinai Hospital; 4 women were excluded from this analysis. There were 42 third-degree tears and 7 fourth-degree tears. EA-US revealed residual defects in 22 patients with third-degree tears and 5 patients with fourth-degree tears (52% vs. 71%; P = 0.44).  Twelve patients with third-degree tears and 4 patients with fourth-degree tears reported AI (29% vs. 57%; P = 0.20). EA-US revealed no evidence of a tear in 14 patients clinically diagnosed with third-degree tears and 1 patient clinically diagnosed with a fourth-degree tear (33% vs. 14%).

CONCLUSION

These data demonstrate deficiencies in diagnosis and repair of OASIS. Continued training for health care providers on identification and effective repair of OASIS may improve outcomes for women who experience this complication.

Management and consequences of obstetrical anal sphincter injuries: Review

Obstetrical anal sphincter injuries (OASI), formerly referred to as "complete" or "incomplete" perineal tears, are a frequent complication of childbirth. They can lead to intestinal consequences (anal incontinence, ano-genital fistula) or sexual consequences (dyspareunia, genital pain). The complexity of management of OASI lies in the multi-factorial nature of these consequences but also in the frequently lengthy interval before their appearance, often long after childbirth. Indeed, while 2.4% of women in childbirth develop OASI, up to 61% of them will present with anal incontinence15 to 25 years after childbirth. Immediate or delayed repair of the sphincter and perineum within a few hours of injury is therefore the rule, but there is no consensus on longer-term management. The patient must be educated on preventive actions (avoidance of pushing or straining, regularization of stool transit, muscle strengthening, etc.). Early detection of anal incontinence leads to prompt management, which is more effective. This review aims to synthesize the information necessary to provide clear and up-to-date patient information on OASI (risk factors and prevalence), the management of OASI, and the management of eventual complications in the setting of dedicated specialty consultations. Dedicated "post-OASI" consultations by a specialist in ano-perineal pathologies could therefore become a first step in the development of care for women, particularly by removing the "shameful" nature of the symptoms.

One Plus One Equals Two-will that do? A trial protocol for a Swedish multicentre randomised controlled trial to evaluate a clinical practice to reduce severe perineal trauma {1}

Background

Severe perineal trauma sustained during childbirth is a serious complication since it can lead to both short- and long-term consequences for women. Some of the methods used to prevent perineal injuries have been evaluated in clinical trials, but there are still gaps in the evidence. A new clinical practice has been introduced, adopted by more than half of the maternity wards in Sweden with the aim of reducing severe perineal trauma. This procedure involves two midwives assisting the woman during the second stage of labour.

Methods/design

In this multicentre randomised controlled trial, 2946 women will be randomised to be assisted by one or two midwives during the second stage of labour. Women age 18–47, who plan for their first vaginal birth, with a singleton pregnancy in cephalic presentation, will be asked to participate when admitted to the maternity ward. Five maternity wards comprising 19,500 births/year in different parts of Sweden will participate in this study. The sample size is powered to demonstrate a 50% reduction (from 4.1–2.0%) in primary outcome, which is the prevalence of severe perineal trauma (3rd and 4th degree). Secondary outcomes will include maternal and neonatal outcomes, women’s experiences, midwives’ experiences of the intervention, incontinence, and pelvic floor symptoms. The primary analysis is intention to treat. Questionnaires will be sent to the women at 1 month and 1 year after the birth to assess women’s experiences, pain, incontinence, pelvic floor symptoms, sexual function, and mental health.

Discussion

It is important for care during labour and birth to be evidence based. There is a strong desire among midwives to reduce the risk of severe perineal trauma. This may lead to new strategies and practices being implemented into practice without scientific evidence. The intervention might have negative side effects or unintended consequences. On the other hand, there is a possibility of the intervention improving care for women.

Trial registration {2a}

ClinicalTrials.gov NCT03770962. Registered on 10 December 2018

How comparable is clinical grading of obstetric anal sphincter injury with that determined by four-dimensional translabial ultrasound?

OBJECTIVES

To evaluate the agreement between grading of obstetric anal sphincter injuries (OASI) on translabial ultrasound (TLUS), using a newly developed algorithm, and grading on postpartum examination. A secondary aim was to assess the correlation between tear severity, as defined on ultrasound, and symptoms of anal incontinence and/or fecal urgency.

METHODS

This was a retrospective study of patients seen at a perineal clinic between 2012 and 2018, after recent primary repair of OASI. All patients underwent a standardized interview including the St Mark's anal incontinence test and four-dimensional TLUS. Post-processing of ultrasound volume data was performed blinded to all other data. Using tomographic ultrasound imaging, a set of eight slices was obtained, and the central six slices were evaluated for sphincter abnormalities. Slices with distortion, thinning or defects were rated as abnormal. The following algorithm was used to grade OASI: a Grade-3a tear was diagnosed if the external anal sphincter (EAS) was abnormal in < 4/6 slices; a Grade-3b tear was diagnosed if the EAS was abnormal in ≥ 4/6 slices; and a Grade-3c/4 tear was diagnosed if both the EAS and internal anal sphincter were abnormal in ≥ 4/6 slices. Clinical grading of OASI was determined according to the Royal College of Obstetricians and Gynaecologists guidelines. Agreement between clinical and TLUS diagnosis of OASI was evaluated using weighted κ.

RESULTS

Of the 260 women seen during the study period, 45 (17%) were excluded owing to missing data or a repeat OASI, leaving 215 complete datasets for analysis. The average follow-up interval was 2.4 months (range, 1-11 months) after OASI and the mean age of the women was 29 years (range, 17-42 years). One hundred and seventy-five (81%) women were vaginally primiparous. OASI was graded clinically as Grade 3a in 87 women, Grade 3b in 80, Grade 3c in 29 and Grade 4 in 19. On imaging, full agreement between clinical and TLUS grading was noted in 107 (50%) women, with a weighted κ of 0.398. In 96 (45%) women, there was disagreement by one category, with a weighted κ of 0.74 and in 12 (6%) there was disagreement by two categories. Twenty-four (11%) women were found to have a normal anal sphincter on imaging. Overall, potential clinical over-diagnosis was noted in 72 (33%) women and potential under-diagnosis in 36 (17%). The seniority of the diagnosing obstetrician did not significantly alter agreement between clinical and sonographic OASI grading (κ 0.44, 0.43, and 0.34, for specialists and senior and junior residents, respectively). The association between symptoms of anal incontinence and/or fecal urgency and TLUS grading did not reach significance (P = 0.052).

CONCLUSIONS

Clinical and TLUS-based grading of OASI showed fair agreement. Clinical over-diagnosis may be increasingly common in our population, although under-diagnosis may still occur in a significant minority. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

A one-stop perineal clinic: our eleven-year experience

Introduction and hypothesis

The perineal clinic is a dedicated setting offering assessment for various childbirth-related presentations including obstetric anal sphincter injuries (OASIs), perineal wound complications, pelvic floor dysfunction and other conditions such as female genital mutilation(FGM). We describe the clinical presentation and outcomes of women from a tertiary perineal clinic based on data collected over an 11-year period.

Methods

This is a retrospective observational study. A one-stop outpatient service was offered to all women who sustained OASIs (postnatally and antenatally in a subsequent pregnancy), perineal complications (within 16 weeks postpartum), FGM and/or peripartum symptoms of urinary/anal incontinence or prolapse. Assessment included history with validated questionnaires, examination and anal manometry and endoanal ultrasound when appropriate. Outcomes were compared among different grades of OASIs. Management of each type of presentation was reported with outcomes.

Results

There were 3254 first attendance episodes between 2006 and 2016. The majority (58.1%) were for OASIs, followed by perineal wound complications. Compared to the lower grades, the higher grades of OASI were associated with poorer outcomes in terms of symptoms, investigations and complications. Women with OASIs had unrelated symptoms such as urinary incontinence, perineal pain and wound infections that needed further intervention. A high proportion(42%) of wound complications required further specialist management.

Conclusion

We describe a dedicated, one-stop perineal clinic model for antenatal and postnatal women for management of perineal and pelvic floor disorders. This comprehensive and novel data will enable clinicians to better counsel women regarding of outcomes after OASI and focus training to minimize risks of morbidities.

Risk of obstetric anal sphincter injuries (OASIS) and anal incontinence: A meta-analysis

BACKGROUND

Obstetric anal sphincter injuries (OASIS) are the commonest cause of anal incontinence in women of reproductive age. We determined the risk of anal sphincter defects diagnosed by ultrasound, and the risk of anal incontinence in (i) all women who deliver vaginally, (ii) in women without clinical suspicion of OASIS, and (iii) after primary repair of sphincter injury, by systematic review.

METHODS

We searched major databases until June 2018, without language restrictions. Random effects meta-analysis was used to obtain pooled estimates of ultrasound diagnosed OASIS and risk of anal incontinence symptoms at various time points after delivery, and of persistent sphincter defects after primary repair. We reported the association between ultrasound diagnosed OASIS and anal incontinence symptoms using relative risk (RR) with 95 % CI.

RESULTS

We included 103 studies involving 16,110 women. Of all women who delivered vaginally, OASIS were diagnosed on ultrasound in 26 % (95 %CI, 21-30, I² = 91 %), and 19 % experienced anal incontinence (95 %CI, 14-25, I² = 92 %). In women without clinical suspicion of OASIS (n = 3688), sphincter defects were observed in 13 % (10-17, I² = 89 %) and anal incontinence experienced by 14 % (95 % CI: 6-24, I² = 95 %). Following primary repair of OASIS, 55 % (46-63, I² = 98 %) of 7549 women had persistent sphincter defect with 38 % experiencing anal incontinence (33-43, I² = 92 %). There was a significant association between ultrasound diagnosed OASIS and anal incontinence (RR 3.74, 2.17-6.45, I² = 98 %).

INTERPRETATION

Women and clinicians should be aware of the high risk for sphincter defects following vaginal delivery even when clinically unsuspected. This underlines the need of careful and systematic perineal assessment after birth to mitigate the risk of missing OASIS. We also noted a high rate of persistent defects and symptoms following primary repair of OASIS. This dictates the need for provision of robust training for clinicians to achieve proficiency and sustain competency in repairing OASIS.

Identification of obstetric anal sphincter injuries (OASIs) and other lacerations: a national survey of nurse-midwives

INTRODUCTION AND HYPOTHESIS

Clinical quality improvement relies on accurate understanding of current practice. We performed a cross-sectional national survey of certified nurse-midwives (CNMs) assessing classification and identification of obstetric anal sphincter injury (OASI) and other delivery lacerations. We hypothesized laceration diagnoses are frequently inaccurate, and delivery records for obstetric lacerations may be of questionable quality.

METHODS

We emailed 6909 American College of Nurse Midwives members an internet-based survey link. Of respondents, we included clinically active CNMs who perform at least one delivery per month. We evaluated laceration knowledge and application using standard descriptive text and images and asked about processes for recording lacerations in the delivery record.

RESULTS

We received 1070 (15.5%) completed surveys and 832 (77.8%) met inclusion criteria. Over 50% characterized their OASI training and ability to identify OASI as good/excellent. Most (79%) had never attended education review on OASI. The overall accuracy for classification and identification of perineal lacerations ranged from 49 to 99%. Non-perineal lacerations were frequently categorized using the perineal/OASI system. Half of respondents (51%) document their deliveries in an electronic medical record but a quarter (28%) are not personally responsible for approving delivery data. Younger participants without a doctoral degree, with self-assessed good/excellent laceration training, and caring for < 50% publicly insured patients had higher accuracy for laceration identification and diagnosis.

CONCLUSIONS

We found high rates of inaccurate laceration diagnosis and inappropriate application of the perineal OASI degree system, suggesting education and training are needed. Clinical studies that rely on delivery diagnosis of OASI may not be reliable.

Variations in use of childbirth interventions in 13 high-income countries: A multinational cross-sectional study

BACKGROUND

Variations in intervention rates, without subsequent reductions in adverse outcomes, can indicate overuse. We studied variations in and associations between commonly used childbirth interventions and adverse outcomes, adjusted for population characteristics.

METHODS AND FINDINGS

In this multinational cross-sectional study, existing data on 4,729,307 singleton births at ≥37 weeks in 2013 from Finland, Sweden, Norway, Denmark, Iceland, Ireland, England, the Netherlands, Belgium, Germany (Hesse), Malta, the United States, and Chile were used to describe variations in childbirth interventions and outcomes. Numbers of births ranged from 3,987 for Iceland to 3,500,397 for the USA. Crude data were analysed in the Netherlands, or analysed data were shared with the principal investigator. Strict variable definitions were used and information on data quality was collected. Intervention rates were described for each country and stratified by parity. Uni- and multivariable analyses were performed, adjusted for population characteristics, and associations between rates of interventions, population characteristics, and outcomes were assessed using Spearman's rank correlation coefficients. Considerable intercountry variations were found for all interventions, despite adjustments for population characteristics. Adjustments for ethnicity and body mass index changed odds ratios for augmentation of labour and episiotomy. Largest variations were found for augmentation of labour, pain relief, episiotomy, instrumental birth, and cesarean section (CS). Percentages of births at ≥42 weeks varied from 0.1% to 6.7%. Rates among nulliparous versus multiparous women varied from 56% to 80% versus 51% to 82% for spontaneous onset of labour; 14% to 36% versus 8% to 28% for induction of labour; 3% to 13% versus 7% to 26% for prelabour CS; 16% to 48% versus 12% to 50% for overall CS; 22% to 71% versus 7% to 38% for augmentation of labour; 50% to 93% versus 25% to 86% for any intrapartum pain relief, 19% to 83% versus 10% to 64% for epidural anaesthesia; 6% to 68% versus 2% to 30% for episiotomy in vaginal births; 3% to 30% versus 1% to 7% for instrumental vaginal births; and 42% to 70% versus 50% to 84% for spontaneous vaginal births. Countries with higher rates of births at ≥42 weeks had higher rates of births with a spontaneous onset (rho = 0.82 for nulliparous/rho = 0.83 for multiparous women) and instrumental (rho = 0.67) and spontaneous (rho = 0.66) vaginal births among multiparous women and lower rates of induction of labour (rho = -0.71/-0.66), prelabour CS (rho = -0.61/-0.65), overall CS (rho = -0.61/-0.67), and episiotomy (multiparous: rho = -0.67). Variation in CS rates was mainly due to prelabour CS (rho = 0.96). Countries with higher rates of births with a spontaneous onset had lower rates of emergency CS (nulliparous: rho = -0.62) and higher rates of spontaneous vaginal births (multiparous: rho = 0.70). Prelabour and emergency CS were positively correlated (nulliparous: rho = 0.74). Higher rates of obstetric anal sphincter injury following vaginal birth were found in countries with higher rates of spontaneous birth (nulliparous: rho = 0.65). In countries with higher rates of epidural anaesthesia (nulliparous) and spontaneous births (multiparous), higher rates of Apgar score < 7 were found (rhos = 0.64). No statistically significant variation was found for perinatal mortality. Main limitations were varying quality of data and missing information.

CONCLUSIONS

Considerable intercountry variations were found for all interventions, even after adjusting for population characteristics, indicating overuse of interventions in some countries. Multivariable analyses are essential when comparing intercountry rates. Implementation of evidence-based guidelines is crucial in optimising intervention use and improving quality of maternity care worldwide.

Selective episiotomy versus no episiotomy for severe perineal trauma: a systematic review with meta-analysis

INTRODUCTION AND HYPOTHESIS

We hypothesized whether a non-episiotomy protocol or administration of selective episiotomy as an intrapartum intervention would modify the incidence of obstetric anal sphincter injuries (OASIS).

METHODS

We registered this systematic review with the PROSPERO database (CRD42018111018). Prospective randomized controlled trials (RCTs) were included from databases until February 2019. The primary outcome was OASIS, and the secondary outcomes were any perineal trauma, duration of the second stage of labor, instrumental delivery, and post-partum hemorrhage. The risk of bias (Cochrane Handbook) and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria were used to assess the RCTs.

RESULTS

A total of 1,833 results (PubMed 650, SCOPUS 1,144, Cochrane Library 33, LILACS 6) were obtained. However, only 2 studies fulfilled the criteria for quantitative analysis and meta-analysis (n = 574). The non-episiotomy arm included two episiotomies (1.7% of deliveries), whereas the selective episiotomy included 33 episiotomies (21.4%). Performance of selective episiotomy demonstrated no difference compared with that of the non-episiotomy group with regard to OASIS (OR = 0.46 [0.15-1.39]; n = 543; I² = 0%,p = 0.17), any perineal trauma (OR = 0.90 [0.61-1.33]; I² = 0%, n = 546, p = 0.59), instrumental delivery (OR = 1.40 [0.80-2.45]; I² = 0%, n = 545, p = 0.24), duration of the second stage of labor (MD = -3.71 [-21.56, 14.14]; I² = 72%,n = 546, p = 0.68), perineal pain (MD = 0.59 [0.01-1.17]; I² = 0%,p = 0.05), and post-partum hemorrhage (OR = 1.75 [0.87-3.54]; I² = 0%,n = 546,p = 0.12). The evaluated studies displayed a low risk of bias in at least four of the seven categories analyzed. GRADE demonstrated a low certainty for severe perineal tears, postpartum hemorrhage, duration of the second stage of labor, and a moderate certainty for any perineal tear.

CONCLUSIONS

There was no significant difference between non-episiotomy and selective episiotomy regarding OASIS. No RCT was able to confirm a benefit of the non-performance of episiotomies in the non-episiotomy arm.

Is endoanal, introital or transperineal ultrasound diagnosis of sphincter defects more strongly associated with anal incontinence?

INTRODUCTION AND HYPOTHESIS

Our aim was to explore the association between anal incontinence (AI) and persistent anal sphincter defects diagnosed with 3D endoanal (EAUS), introital (IUS) and transperineal ultrasound (TPUS) in women after obstetric anal sphincter injury (OASI) and study the association between sphincter defects and anal pressure.

METHODS

We carried out a cross-sectional study of 250 women with OASI recruited during the period 2013-2015. They were examined 6-12 weeks postpartum or in a subsequent pregnancy with 3D EAUS, IUS and TPUS and measurement of anal pressure. Prevalence of urgency/solid/liquid AI or flatal AI and anal pressure were compared in women with a defect and those with an intact sphincter (diagnosed off-line) using Chi-squared and Mann-Whitney U test.

RESULTS

At a mean of 23.6 (SD 30.1) months after OASI, more women with defect than those with intact sphincters on EAUS had AI; urgency/solid/liquid AI vs external defect: 36% vs 13% and flatal AI vs internal defect: 27% vs 13%, p < 0.05. On TPUS, more women with defect sphincters had flatal AI: 32% vs 13%, p = 0.03. No difference was found on IUS. Difference between defect and intact sphincters on EAUS, IUS and TPUS respectively was found for mean [SD] maximum anal resting pressure (48 [13] vs 55 [14] mmHg; 48 [12] vs 56 [13] mmHg; 50 [13] vs 54 [14] mmHg) and squeeze incremental pressure (33 [17] vs 49 [28] mmHg; 37 [23] vs 50 [28] mmHg; 36 [18] vs 50 [30] mmHg; p < 0.01).

CONCLUSIONS

Endoanal ultrasound had the strongest association with AI symptoms 2 years after OASI. Sphincter defects detected using all ultrasound methods were associated with lower anal pressure.

Coaching a slow birth with the woman in an empowered position may be less harmful than routine hands-on practice to protect against severe tears in birth - A discussion paper

BACKGROUND

Different hands-on interventions to protect women from severe perineal tears after birth have been widely implemented. Evidence to support the routine use of hands-on interventions to reduce severe tears is mainly based on aggregated data from observational studies.

AIM

To critically discuss the current evidence for the implementation of hands-on intervention as a routine practice to protect women from severe tears after birth.

DISCUSSION

Observational studies have been used to justify the routine use of hands-on intervention to protect women from severe perineal tears despite randomized controlled trials and systematic reviews showing lack of benefit. There is strong evidence supporting the slow speed at the time of birth to prevent severe perineal tears. While hands-on intervention does reduce the speed of birth, it may have a negative effect on the birth process, on neonatal outcomes and women's agency.

CONCLUSION

Evidence-based practice requires sufficient evaluation of interventions before being implemented in clinical practice as well as valuing the level of evidence when making clinical decisions. Evaluation of hands-on interventions to protect women from severe perineal tears must include not just one outcome of interest, but also an assessment of how the intervention interferes with the normal mechanism of birth, and how it affects neonatal outcomes and the autonomy of women.

Effect of subsequent vaginal delivery on bowel symptoms and anorectal function in women who sustained a previous obstetric anal sphincter injury

Introduction and hypothesis

Our primary objective was to prospectively evaluate anorectal symptoms, anal manometry and endoanal ultrasound (EAUS) in women who followed the recommended mode of subsequent delivery following index obstetric anal sphincter injuries (OASIs) using our unit’s standardised protocol. Our secondary objectives were to evaluate the role of internal anal sphincter defects and also to compare outcomes in a subgroup of symptomatic women with normal anorectal physiology.

Methods

This is a prospective follow-up study of pregnant women with previous OASIs who were counselled regarding subsequent mode of delivery between January 2003 and December 2014. Assessment involved the St Mark’s Incontinence Score (SMIS), anal manometry and EAUS at both antepartum and 3-month postpartum visits. Data were analysed using Wilcoxon and Mann–Whitney U tests.

Results

Three hundred and fifty women attended the perineal clinic over the study period, of whom 122 met the inclusion criteria (99 vaginal delivery [VD], 23 caesarean section). No significant worsening of anorectal symptoms was observed following subsequent delivery in the VD group (p = 0.896), although a reduced squeeze pressure was observed at 3 months postpartum (p < 0.001). There were no new defects on EAUS in either group.

Conclusions

This study showed no significant worsening of bowel symptoms and sphincter integrity apart from lower squeeze pressures at 3 months postpartum in the VD group when our standardised protocol was used to recommend subsequent mode of delivery. In the absence of a randomised study, use of this protocol can aid clinicians in their decision-making.