Levator ani muscle avulsion during childbirth: a risk prediction model

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

OBJECTIVES

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Pelvic Floor Symptoms 4 Years After Elective Labor Induction: A Randomized Clinical Trial

IMPORTANCE

Pelvic floor disorders are common and burdensome. Data on the effect of induction of labor on pelvic floor disorders are sparse and results are mixed.

OBJECTIVE

Our aim was to evaluate whether elective labor induction in nulliparous women increases the risks of symptomatic urinary incontinence (UI), anal incontinence (AI), or pelvic organ prolapse (POP) 4 years after delivery.

STUDY DESIGN

In this single-site follow-up study of "A Randomized Trial of Induction Versus Expectant Management" (ARRIVE) that randomized low-risk nulliparous women with a singleton fetus to elective induction of labor versus expectant management, we compared pelvic floor symptoms between groups at a median of 4 years (interquartile range, 3.5-5.3) after first delivery using validated questionnaires.

RESULTS

Seventy hundred sixty-six of 1,042 (74%) original participants responded, and 647 participants (62%) were included in the analysis after exclusions. The overall prevalence rates of symptomatic moderate to severe UI, AI, and POP were 21%, 14%, and 8%, respectively. There were no significant differences in any of the outcomes between women randomized to induction of labor and those to expectant management, either in unadjusted or adjusted analyses. There were also no differences in secondary outcomes, including subtypes of UI or flatal versus stool incontinence.

CONCLUSIONS

In this single-site study, we found no significant differences in any UI, AI, and POP symptoms between nulliparous women randomized to elective induction of labor and to expectant management; however, for the least frequent outcome (POP), meaningful differences cannot be ruled out.

Pelvic floor dysfunction after intervention, compared with expectant management, in prolonged second stage of labour: A population-based questionnaire and cohort study

OBJECTIVE

To investigate the effect of vacuum extraction (VE) or caesarean section (CS), compared with expectant management, on pelvic floor dysfunction (PFD) 1-2 years postpartum in primiparous women with a prolonged second stage of labour.

DESIGN

A population-based questionnaire and cohort study.

SETTING

Stockholm, Sweden.

POPULATION

A cohort of 1302 primiparous women with a second stage duration of ≥3 h, delivering from December 2017 to November 2018.

METHODS

The 1-year follow-up questionnaire from the Swedish National Perineal Laceration Register was distributed 12-24 months postpartum. Exposure was VE or CS at 3-4 h or 4-5 h, compared with expectant management.

MAIN OUTCOME MEASURES

Pelvic floor dysfunction was defined as at least weekly symptoms of urinary incontinence, pelvic organ prolapse or a Wexner score of ≥4. The risk of PFD was calculated using Poisson regression with robust variance estimation, presented as crude and adjusted relative risks (RRs and aRRs) with 95% confidence intervals (95% CIs). The implication of obstetric anal sphincter injury (OASI) on pelvic floor disorders was investigated through mediation analysis.

RESULTS

In total, 35.1% of women reported PFD. Compared with expectant management, the risk of PFD was increased after VE at 3-4 h (aRR 1.33, 95% CI 1.06-1.65) and 4-5 h (aRR 1.34, 95% CI 1.05-1.70), but remained unchanged after CS. The increased risk after VE was not mediated by OASI.

CONCLUSIONS

Pelvic floor dysfunction was common in primiparous women after a prolonged second stage, and the risk of PFD increased after VE but was unaffected by CS, compared with expectant management. If a spontaneous vaginal delivery eventually occurred, allowing an extended duration of labour did not increase the risk of PFD.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association Between Urinary Stress Incontinence and Levator Avulsion Detected by 3D Transperineal Ultrasound

PURPOSE

 To determine the association between levator avulsion and urinary stress incontinence (USI) by 3/4D transperineal ultrasound.

MATERIALS AND METHODS

 842 patients who were admitted to our hospital from 2016 to 2019 were recruited for our study. 3D/4D transperineal ultrasound was performed. After standard interview and clinical evaluation, general conditions and levator hiatus data were collected and measured to compare with each group. The odds ratio (OR) of USI symptoms or ultrasound features with levator avulsion were calculated.

RESULTS

 A total of 593 women were studied: 204 suffered from levator avulsion (96 cases of left-side avulsion, 80 cases of right-side avulsion and 28 cases of bilateral avulsion) and 389 women had no avulsion. The gravidity and episiotomy conditions of the avulsion groups were significantly different from the no-avulsion group. Significant differences were found in the transverse diameters and anteroposterior diameters between the levator avulsion group and the no-avulsion group, but there was no difference among the avulsion groups, regardless of whether the patient was at rest or performing the Valsalva maneuver. Interestingly, a significant difference was found in the presence of USI symptoms between the uni-avulsion group and the no-avulsion group. The odds ratio (OR) of USI symptoms in the uni-avulsion group is 2.786 (95 %CI, 1.663-4.669), but 0.939 (95 %CI, 0.276-3.199) for the bilateral avulsion and no-avulsion groups.

CONCLUSION

 Unilateral levator avulsion may be a risk factor for urinary stress incontinence.

Effect of the length of the second stage of labor on pelvic floor dysfunction

BACKGROUND

Pelvic floor dysfunction refers to any combination of incontinence, overactive bladder, pelvic organ prolapse, and sexual dysfunction. Pelvic floor dysfunction affects approximately 25% to 30% of women and is linked to parity and age. Some obstetrical risk factors have been highlighted, though the second stage of labor has not been as thoroughly investigated. Allowing a longer second stage has been suggested as a method of reducing the rates of cesarean delivery in nulliparous women, though it has also been linked to pelvic floor injuries.

OBJECTIVE

This study aimed to determine the effect of the length of the second stage of labor on self-reported pelvic floor dysfunction.

STUDY DESIGN

This was a single-center prospective cohort study in a tertiary referral obstetrical unit. Nulliparous women attending routine antenatal clinics were recruited to complete the Australian Pelvic Floor Questionnaire during pregnancy and again 3 months after delivery. The primary outcome in this study was the effect of the length of the second stage of labor on total pelvic floor scores when analyzed using multiple regression. The models were adjusted for the mother's age, mother's body mass index, length of the second stage of labor, fetal birthweight, mode of delivery, and perineal trauma. The secondary outcomes included the comparison of maternal, obstetrical, and functional pelvic floor outcomes based on the mode of delivery and the length of the second stage of labor.

RESULTS

Among the 295 women who were recruited, the length of the second stage of labor and body mass index were associated with self-reported bladder dysfunction on multiple regression, whereas maternal age was protective. Compared with those with 60 to 120 minutes or <60 minutes of second stage of labor, women with that longer than 120 minutes had higher rates of stress incontinence (85.7% [>120 minutes] vs 41.7% [60-120 minutes] or 52.5% [<60 minutes], P=.001), urinary urgency (89.3% [>120 minutes] vs 39.6% [60-120 minutes] or 53.8% [<60 minutes], P<.001), and fecal incontinence (10.7% [>120 minutes] vs 0% [60-120 minutes] or 1.2% [<60 minutes], P=.027). There were no differences in the rates of sexual activity or dyspareunia. Women delivering vaginally had higher rates of stress incontinence (57.6% vs 38.0%, P=.006) than those undergoing cesarean delivery, though there were no differences in other pelvic floor symptoms or pelvic floor scores.

CONCLUSION

A prolonged second stage of labor is associated with more self-reported bladder dysfunction at 3 months postnatal in primiparous women. Women with a longer second stage of labor should be informed about the risk of short-term bladder dysfunction, though the prevalence of long-term sequelae is unknown.

All or nothing? A second look at partial levator avulsion

OBJECTIVE

To define associations between partial levator trauma and symptoms and signs of pelvic organ prolapse (POP).

METHODS

This was a retrospective study of 3484 women attending a tertiary urogynecology unit for symptoms of pelvic floor dysfunction between January 2012 and February 2020. All women underwent a standardized interview, clinical pelvic organ prolapse quantification (POP-Q) examination and tomographic ultrasound imaging of the pelvic floor. Women with full levator avulsion were excluded from analysis. Partial levator avulsion was quantified using the tomographic trauma score (TTS), in which slices 3-8 are scored bilaterally for abnormal insertions. Binomial multiple logistic regression was analyzed independently for the outcome variables prolapse symptoms, symptom bother and objective prolapse on clinical examination and imaging, with age and body mass index as covariates. Two continuous outcome variables, prolapse bother score and hiatal area on Valsalva, were analyzed using multiple linear regression.

RESULTS

Of the 3484 women, ultrasound data were missing or incomplete in 164 due to lack of equipment, clerical error and/or inadequate image quality. Full levator avulsion was diagnosed in 807 women, leaving 2513 for analysis. TTS ranged from 0-10, with a median of 0. Partial trauma (TTS > 0) was observed in 667/2513 (26.5%) women. All subjective and objective measures of POP were associated significantly with TTS, most strongly for cystocele. Associations were broadly linear and similar for all slice locations but disappeared after accounting for hiatal area on Valsalva.

CONCLUSION

Partial avulsion is associated with POP and prolapse symptoms. This association was strongest for cystocele, both on POP-Q and ultrasound imaging. The effect of partial avulsion on POP and prolapse symptoms is explained fully by its effect on hiatal area. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion

OBJECTIVE

To estimate the diagnostic test accuracy of magnetic resonance imaging (MRI) and pelvic floor ultrasound for levator ani muscle (LAM) avulsion in a general parous population, with view to establishing if ultrasound could substitute for MRI to diagnose LAM avulsion.

METHODS

This was a cross-sectional study of 135 women 4 years after their first delivery. Signs and symptoms of pelvic floor dysfunction were assessed using validated methods. All women underwent four-dimensional transperineal ultrasound (TPUS), three-dimensional endovaginal ultrasound (EVUS) and MRI. Images were acquired at rest, on pelvic floor muscle contraction (PFMC) and on maximum Valsalva maneuver, and analyzed by two blinded observers. Predefined cut-off values were used to diagnose LAM avulsion. In the absence of a reference standard, latent class analysis (LCA) was used to establish diagnostic test characteristics for LAM avulsion as the primary outcome measure. Secondary outcomes were kappa (κ) agreement between imaging techniques, intraclass correlation coefficients (ICC) for hiatal measurements at rest, on PFMC and on maximum Valsalva maneuver, and the association of LAM avulsion with signs and symptoms of pelvic floor dysfunction.

RESULTS

The prevalence of LAM avulsion was 23.0% for MRI, 11.1% for TPUS and 17.8% for EVUS. The prevalence of LAM avulsion using LCA was 15.7%. The sensitivity for LAM avulsion of TPUS (71% (95% CI, 50-90%)) and EVUS (91% (95% CI, 74-100%)) was lower than that of MRI (100% (95% CI, 84-100%)). The specificity of TPUS (100% (95% CI, 97-100%)) and EVUS (95% (95% CI, 91-99%)) was higher than that of MRI (91% (95% CI, 85-97%)). MRI and EVUS had high predictive values for the assessment of major LAM avulsion (positive predictive value (PPV), 95% and negative predictive value (NPV), 100%; PPV, 100% and NPV, 98%, respectively), while TPUS had high predictive values for minor LAM avulsion (PPV, 100% and NPV, 95%). Major LAM avulsion on MRI and EVUS was associated with anterior vaginal wall prolapse, which was not found for TPUS. The agreement in the diagnosis of LAM avulsion (κ, 0.69) and hiatal measurements (ICC, 0.60-0.81) was highest between MRI and EVUS.

CONCLUSIONS

Pelvic floor ultrasound can be implemented as a triage test to assess parous women for LAM avulsion because of its high specificity. Ultrasound cannot substitute for MRI because of its lower sensitivity. The predictive ability of ultrasound is moderate for the presence, and very good for the absence, of LAM avulsion. A positive test should be confirmed by a different observer or imaging technique. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

A review of levator ani avulsion after childbirth: Incidence, imaging and management

Key Content • Levator ani muscle (LAM) avulsion injury occurs occultly during childbirth, most commonly during operative vaginal deliveries. • Injuries of levator ani have long term sequelae for pelvic floor health. As life expectancy increases the burden of disease upon urogynaecology services will need to be considered. • Diagnosis of this condition can be difficult as there is no agreed 'gold standard' imaging modality. • There is no consensus regarding surgical management of LAM avulsion. Learning objectives • Review anatomy and function of levator ani muscle • Identify the risk factors for levator ani avulsion injury • Role of imaging to appropriately identify LAM injury and current management options including appropriate follow up • Management of subsequent pregnancy following LAM avulsion Ethical issues • Is there value to the patient in diagnosing levator ani avulsion when there is no recommended treatment for these injuries?

Associations of Maternal Complaints to Levator Ani Muscle Trauma within 9 Months after Vaginal Birth: A Prospective Observational Cohort Study

Introduction. Pelvic floor trauma in the form of partial or complete avulsions of the levator ani muscle (LAM) affects 6-42% of women after vaginal birth and can cause tremendous long-term morbidity. Many studies assessed morphological pelvic floor trauma after childbirth but lacked to evaluate women’s associated short-term complaints. A proper assessment of trauma and subjective complaints after birth could help to assess possible associations between them and their relevance to women’s daily life. Therefore, we aimed to assess women’s complaints within the first months after birth in association to their LAM trauma. Materials and Methods. Between 3/2017 and 4/2019, we prospectively evaluated vaginal births of 212 primiparous women with singletons in $\text{vertex}\text{presentation}\ge 36+0$ gestational weeks for levator ani muscle (LAM) trauma by translabial ultrasound, for pelvic organ prolapse by clinical examination, and for urogynecological complaints using questionnaires 1-4 days (P1), 6-10 weeks (P2), and 6-9 months (P3) after birth. The questionnaires were self-designed but oriented to and modified from validated questionnaires. Women’s complaints were evaluated for P1-P3 according to their LAM trauma state. Results. At P1, 67% of women showed an intact LAM, whereas 14.6% presented a hematoma, 6.6% a partial avulsion (PAV), and 11.8% a complete avulsion (CAV). At P2, 75.9% showed an intact LAM, 9.9% a PAV, and 14.2% a CAV. At P3, 72.9% of women with a LAM trauma in P1 and/or P2 were assessed with 21.6% being intact and 39.2% having a PAV and CAV, respectively. Obstetrical and baseline characteristics differed slightly between the groups. When comparing the time before and during pregnancy with the time after childbirth, birth itself affected women’s complaints in all LAM state groups, but the presence of a LAM trauma, especially a CAV, had more negative effects. Conclusions. Vaginal birth changes the anatomical structure of the maternal birth canal and genital tract, and it alters women’s perceptions and body function. In our study, LAM trauma did not change these effects tremendously within the first months. Therefore, other maternal, fetal, and obstetrical factors need consideration for the explanation of maternal complaints, in addition to long-term effects of trauma and dysfunction of the LAM and other birth canal structures.

Anal incontinence after a prolonged second stage of labor in primiparous women

The objective was to investigate the effect of delivery mode on anal incontinence 1–2 years after delivery in primiparous women with prolonged second stage of labor. This population-based cohort and questionnaire study performed in Stockholm Region, Sweden, included 1302 primiparous women with a second stage ≥ 3 h from December 1st, 2017 through November 30th, 2018. Background characteristics and outcome data were retrieved from computerized records. Questionnaires based on Wexner score were distributed 1–2 years after delivery. Risk of anal incontinence, defined as Wexner score ≥ 2, was calculated using logistic regression and presented as crude and adjusted odds ratios (OR and aOR) with 95% confidence intervals (CI). Compared with cesarean section, vacuum extraction was associated with anal incontinence (aOR 2.25, 95% CI 1.21–4.18) while spontaneous delivery was not (aOR 1.55, 95% CI 0.85–2.84). Anal incontinence was independently associated with obstetric anal sphincter injuries (aOR 2.03, 95% CI 1.17–3.5) and 2nd degree perineal tears (aOR 1.36, 95% CI 1.03–1.81) compared with no or 1st degree perineal tear. Obstetric anal sphincter injury at vacuum extraction inferred the highest risk of anal incontinence (aOR 4.06, 95% CI 1.80–9.14), compared with cesarean section. Increasing duration of the prolonged second stage did not affect the risk.

Prediction models in gynaecology: Transparent reporting needed for clinical application

The clinical application of prediction models is increasing within the field of gynaecology and obstetrics. This is mostly due to the fact that clinicians and patients prefer individualized counselling and person specific, more objective outcome assessment. To prevent using inadequate models, it is important to construct and perform prediction model studies correctly. Therefore, the TRIPOD statement (the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) was developed. The aim of this review is to obtain an overview of the existing published prediction models for benign gynaecology and to investigate to what extent these studies meet the TRIPOD criteria. We performed a literature search in the databases PubMed, Embase and Cochrane Library from inception to August 2020. Searching the cross-references of the relevant studies within our search identified additional articles. Publications were included if the aim of the study was to develop a multivariable prediction model within the field of benign gynaecology. Two independent reviewers extracted the data. Analysis of the studies was performed by using a checklist derived from the TRIPOD criteria. Based on our search, 2487 studies were selected, including potential duplications. Eventually, a total of twenty-two studies were selected. 91% of these studies handled their predictors by univariable analysis before developing a multivariable prediction model. Fifteen studies described having missing data, but not all of them (9%) handled these missing data. Four different internal validation methods were used in twenty studies. Fifteen studies (68%) had prediction models with a C-index ≥ 0.7, which indicates a good model. Half of the studies (50%) did not measure the calibration, overall performance was described in two studies (9%). External validation was performed in 9% of the studies. The correct development of a prediction model within benign gynaecology and subsequent transparent reporting of the model development is important to facilitate clinical use. Without transparent reporting, wrong assumptions can be made leading to incorrect application of a specific prediction model. This overview shows that excepting carrying out an external validation, only one article met all the criteria. Therefore, we strongly recommend use of the TRIPOD criteria for developing and validating a prediction model (study). In addition, prior to publication, content experts should critically and statistically review the prediction model. If too many criteria are not met, refusing publication should be considered.

In vivo evaluation of the levator ani muscle in primiparous women using diffusion tensor imaging and fiber tractography

OBJECTIVE

To characterize the levator ani muscle (LAM) injury after first vaginal delivery and investigate the clinical application of diffusion tensor imaging (DTI) and fiber tractography in evaluating the LAM.

METHODS

Fifty-eight primiparous women at 6 weeks after vaginal delivery and 27 nulliparous women as controls underwent T2-weighted sequence and DTI sequence of the pelvic floor. A LAM scoring system was used to characterize the morphological changes. Fiber tractography of each major subdivision of LAM was performed, followed by assessment of the quality of fiber tracking. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), fiber volume, and length were calculated.

RESULTS

Puborectalis and iliococcygeus injuries were observed in 30/58 (51.7%) and 10/58 (17.2%) primiparae, respectively. No LAM defects were identified in the control group. For the puborectalis, the FA values were lower (P = 0.010) and ADC values were higher (P = 0.024) in the primiparous group than in the control group. For the iliococcygeus, the fiber volume values were lower in the primiparous group than in the control group (P = 0.004).

CONCLUSION

Vaginal delivery can result in LAM injury at the puborectalis. DTI parameters can assist in the quantitative diagnosis of the LAM injury.

Which factors are associated with anal incontinence after obstetric anal sphincter injury?

OBJECTIVES

Obstetric anal sphincter injury (OASI) is an important factor in the etiology of anal incontinence. This study aimed to evaluate whether anal sphincter defects, levator avulsion or levator ballooning after OASI are associated with severity of anal incontinence. Furthermore, we evaluated whether factors such as constipation and altered stool consistency are associated with symptoms of incontinence after OASI.

METHODS

In this multicenter prospective observational cohort study, women with OASI were invited to participate at least 3 months after primary repair. All women completed validated questionnaires, including St Mark's incontinence score, Bristol stool scale (BSS) and Cleveland clinic constipation score (CCCS), and underwent four-dimensional (4D) transperineal ultrasound for assessment of the levator ani muscle and anal sphincter.

RESULTS

In total, 220 women were included. Median follow-up was 4 months (range, 3-98 months). Univariate linear regression analysis showed an association of St Mark's incontinence score with a residual defect of the external anal sphincter (EAS) (β, 1.55 (95% CI, 0.04-3.07); P = 0.045), higher parity (β, 0.85 (95% CI, 0.02-1.67); P = 0.046), BSS (β, 1.28 (95% CI, 0.67-1.89); P < 0.001) and CCCS (β, 0.36 (95% CI, 0.18-0.54); P < 0.001). However, multivariate linear regression found an association of St Mark's incontinence score only with BSS (β, 1.50 (95% CI, 0.90-2.11); P < 0.001) and CCCS (β, 0.46 (95% CI, 0.29-0.63); P < 0.001).

CONCLUSIONS

Residual defects of the EAS, detected on 4D transperineal ultrasound, are associated with severity of anal incontinence symptoms measured using St Mark's incontinence score 4 months after OASI repair. Furthermore, clinical factors such as constipation and altered stool consistency appear to influence this association and may therefore play a more important role in clinical management. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Natural history of levator ani muscle avulsion 4 years following childbirth

OBJECTIVES

The primary aim was to evaluate prospectively the natural history of levator ani muscle (LAM) avulsion 4 years following first delivery and its correlation with signs and symptoms of pelvic floor dysfunction (PFD). The secondary aim was to investigate the effect of a second vaginal delivery on the incidence of LAM avulsion and PFD.

METHODS

This was a prospective longitudinal study of nulliparous women recruited antenatally, who were assessed at 36 weeks' gestation and 3 months, 1 year and 4 years postpartum for signs and symptoms of PFD and presence of LAM avulsion. Pelvic floor muscle strength was assessed by digital palpation, and pelvic organ prolapse (POP) was assessed using the POP quantification (POP-Q) system. Validated questionnaires were used to evaluate urinary, bowel and sexual function and symptoms of POP. Transperineal ultrasound was performed to assess LAM integrity and hiatal biometry. Differences in signs and symptoms of PFD over time were evaluated using a linear mixed model, separately in women who had had one delivery and in those who had two or more deliveries during the study period.

RESULTS

Of 269 women recruited, 147 (55%) attended the 4-year follow-up and were examined at a mean interval of 3.8 ± 0.4 years after their first delivery. Of these, 74 (50%) had a subsequent delivery. The prevalence of LAM avulsion 4 years after a first vaginal delivery was 13%, with no difference between women who had one and those who had two or more vaginal deliveries. Women with an intact LAM and one or more deliveries showed no change in signs and symptoms of PFD at 4 years compared with the previous assessments. Of women with one vaginal delivery who were diagnosed with LAM avulsion 3 months or 1 year postpartum, those in whom the LAM avulsion was no longer evident at 4 years (42%) showed worsening of POP-Q measurements, whereas those with persistent LAM avulsion (58%) showed significant worsening in pelvic floor muscle strength and hiatal area on ultrasound. After a second vaginal delivery, no new avulsions were diagnosed, however, previous LAM avulsion became more extensive in 44% of women and hiatal area increased in women with persistent LAM avulsion.

CONCLUSIONS

The first vaginal delivery carries the greatest risk for LAM avulsion, with impact on signs of PFD 4 years later. A second vaginal delivery could result in deterioration of LAM avulsion, but no new avulsions were found. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Levator ani avulsion: a Systematic evidence review (LASER)

BACKGROUND

There is variation in the reported incidence rates of levator avulsion (LA) and paucity of research into its risk factors.

OBJECTIVE

To explore the incidence rate of LA by mode of birth, imaging modality, timing of diagnosis and laterality of avulsion.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, CINAHL, AMED and MIDIRS with no language restriction from inception to April 2019.

STUDY ELIGIBILITY CRITERIA

A study was included if LA was assessed by an imaging modality after the first vaginal birth or caesarean section. Case series and reports were not included.

DATA COLLECTION AND ANALYSIS

RevMan v5.3 was used for the meta-analyses and SW SAS and STATISTICA packages were used for type and timing of imaging analyses.

RESULTS

We included 37 primary non-randomised studies from 17 countries and involving 5594 women. Incidence rates of LA were 1, 15, 21, 38.5 and 52% following caesarean, spontaneous, vacuum, spatula and forceps births, respectively, with no differences by imaging modality. Odds ratio of LA following spontaneous birth versus caesarean section was 10.69. The odds ratios for LA following vacuum and forceps compared with spontaneous birth were 1.66 and 6.32, respectively. LA was more likely to occur unilaterally than bilaterally following spontaneous (P < 0.0001) and vacuum-assisted (P = 0.0103) births but not forceps. Incidence was higher if assessment was performed in the first 4 weeks postpartum.

CONCLUSIONS

LA incidence rates following caesarean, spontaneous, vacuum and forceps deliveries were 1, 15, 21 and 52%, respectively. Ultrasound and magnetic resonance imaging were comparable tools for LA diagnosis.

TWEETABLE ABSTRACT

Levator avulsion incidence rates after caesarean, spontaneous, vacuum and forceps deliveries were 1, 15, 21 and 52%, respectively.

Adding Insult to Injury: Levator Ani Avulsion in Women With Obstetric Anal Sphincter Injuries

OBJECTIVE

In women with obstetric anal sphincter injuries, we compared the rate of major levator ani avulsion after forceps-assisted delivery versus spontaneous vaginal delivery.

METHODS

Prospective cohort of primiparous women with obstetric anal sphincter injuries. The primary outcome was the rate of major levator ani avulsion as measured by 3-dimensional transvaginal ultrasonography performed between 1 and 2 weeks postpartum. Secondary outcomes included ultrasonographic anteroposterior hiatal diameter, levator hiatal area, and levator-urethra gap, and differences in validated pelvic disorder questionnaires scores at 1 to 2 and 13 weeks postpartum.

RESULTS

Sixty-two women (30 spontaneous deliveries, 32 forceps deliveries) were included in the final analysis. After controlling for delivery variables, women who underwent forceps-assisted delivery were more likely to experience a major avulsion as compared with those who underwent spontaneous delivery (21/32, [65.6%] vs 8/30 [26.7%]; odds ratio, 5.9; 95% confidence interval, 1.5-24.5; P = 0.014). They were also more likely to have larger levator-urethra gaps bilaterally (P = 0.012, 0.016). After controlling for potential confounders, levator ani avulsion was independently associated with persistent anal incontinence symptoms at 13 weeks postpartum (P = 0.02).

CONCLUSIONS

In women with obstetric anal sphincter injuries, the risk of levator ani avulsion is almost 6 times higher after forceps-assisted vaginal delivery as compared with spontaneous vaginal delivery. In those with avulsion, recovery of anal continence is compromised, suggesting that adding insult (avulsion) to injury (obstetric anal sphincter injury) may have negative functional consequences.

Effects of Oxytocin for Induction and Augmentation of Labor on Pelvic Floor Symptoms and Support in the Postpartum Period

OBJECTIVE

The aim of the study was to determine whether oxytocin for induction or augmentation of labor impacts the incidence or persistence of pelvic floor symptoms and support 5 to 10 weeks after first vaginal delivery.

METHODS

Participants in this prospective cohort study were nulliparous women 18 years or older that delivered vaginally at 37 weeks gestation or more and completed the Epidemiology of Prolapse and Incontinence Questionnaire (EPIQ) and the Pelvic Organ Prolapse Quantification examination in third trimester and 5 to 10 weeks postpartum. We compared the incidence and persistence of symptomatic EPIQ domains and worse vaginal support (maximal vaginal descent ≥0 cm) between women who received oxytocin with those that did not (with or without prostaglandin or mechanical methods in both groups). We performed modified binomial regression to calculate adjusted relative risks of each outcome with 95% confidence intervals.

RESULTS

The mean (SD) age of the 722 participants was 28.3 (5.2) years; 20% were Hispanic. There were no significant differences according to oxytocin exposure in either incidence or persistence of symptomatic EPIQ domains or worse vaginal support. We found similar results in sensitivity analyses comparing women who received oxytocin as the sole pharmacologic agent to women who received no pharmacologic agent. After adjusting for demographic and obstetric factors associated with incidence and persistence of symptoms and support, oxytocin exposure continued to have no effect.

CONCLUSIONS

Oxytocin during labor does not significantly increase the risks for the incidence or persistence of pelvic floor symptoms or worse vaginal support in the early postpartum period, although power for less frequent outcomes was limited.

Pelvic floor ultrasound finds after episiotomy and severe perineal tear: systematic review and meta-analysis

AIM

Vaginal delivery is a well-known risk factor for pelvic floor muscle (PFM) injuries, mainly when associated to prolonged labor, instrumental birth and perineal trauma such as episiotomy and perineal tears. The purpose of this meta-analysis was to test the hypothesis that episiotomy and severe perineal tear may increase the risk of pelvic floor damage.

METHODS

We performed a systematic literature search through electronic databases including MEDLINE via PubMed, LILACS via BVS, Embase via Elsevier and Cochrane Library up to January 2019. We included articles that reported as outcome one or more morphological aspects of the PFM evaluated by ultrasonography in primiparous women three to 24 months postpartum. This review is registered in the PROSPERO database (registration number: CRD42017075750).

RESULTS

the final selection was composed of 18 articles for the systematic review, and 10 for the meta-analysis. Women with levator ani muscle (LAM) avulsion were 1.77 times more likely to have undergone episiotomy (OR = 1.77, CI 95% 1.25-2.51, five trials), 4.31 times more likely to have severe perineal tear (OR = 4.31, CI 95% 2.34-7.91, two trials). Women with defects in the anal sphincters were 2.82 times more likely to have suffered severe perineal tear (OR = 2.82, 95% CI 1.71-4.67, three trials).

CONCLUSIONS

Both episiotomy and severe perineal tear are risk factors for LAM avulsion and anal sphincter injury, and this can be useful for identifying women who are at greater risk of developing PFM dysfunctions.

The effect of replacing vacuum with forceps in operative vaginal delivery: an observational study

INTRODUCTION AND HYPOTHESIS

An increase in vaginal delivery with forceps may increase rates of pelvic floor trauma. This study was designed to predict trauma rates resulting from policies preferencing forceps.

METHODS

This is an observational cohort study utilizing data from 660 primiparae enrolled in an RCT in two tertiary obstetric units in Sydney, Australia. Participants were assessed clinically and with 4D translabial ultrasound in the late third trimester and again at 3-6 months postpartum. Incidence of trauma associated with mode of delivery was adjusted to reflect change associated with a conversion of vacuum to forceps delivery. Primary outcome measures were third-/fourth-degree tear, levator avulsion (LA) and external anal sphincter (EAS) trauma diagnosed sonographically.

RESULTS

Five hundred four women were seen at a mean of 5.1 (2.3-24.3) months postpartum. After exclusion of 21 because of missing data, 483 women were analysed: 112 (23%) had a CS, 268 (55%) a normal vaginal delivery (NVD), 69 (14%) a vacuum (VD) and 34 (7%) a forceps (FD). One hundred fifty-two women had EAS trauma and/or LA; 17 sustained both. After VD, 32/69 (46%) women suffered LA and/or EAS trauma; after FD, it was 33/34 (97%). Converting VD to FD was estimated to result in an increase in trauma from 152/483 (31%) to 187/483 (39%). A formula can be generated based on local obstetric and ultrasound data to estimate trauma incidence.

CONCLUSIONS

A change in obstetric practice resulting in the conversion of primary VD to primary FD would be expected to substantially increase the likelihood of pelvic floor trauma.

Prevalence of levator ani avulsion in a multicenter study (PAMELA study)

PURPOSE

The objective is to determine the prevalence of levator ani muscle (LAM) avulsion using four-dimensional ultrasound in primiparous women after vaginal delivery and according to delivery mode.

METHODS

This prospective, multicenter study included 322 women evaluated at 6-12 months postpartum by four-dimensional transperineal ultrasound to identify levator ani muscle avulsion. The researcher who performed the ultrasound was blinded to all clinical data. Meaningful data about the birth were also recorded: mode of delivery, mother's age and body mass index, duration of second stage, episiotomy, perineal tearing, anesthesia, assistant, head circumference and fetal weight.

RESULTS

303 volumes were valid for evaluation. The overall prevalence of levator ani muscle avulsion was 18.8% (95% CI 14.4-23.2%). In our multivariate analysis, only mode of delivery reached statistical significance as a risk factor for levator ani muscle avulsion (p < 0.001). The prevalence according to the different modes of delivery was 7.8% in spontaneous delivery, 28.8% in vacuum-assisted and 51.1% in forceps-assisted delivery. Compared with spontaneous delivery, the OR for LAM avulsion was 12.31 with forceps (CI 95% 5.65-26.80) and 4.78 with vacuum-assisted delivery (CI 95% 2.15-10.63).

CONCLUSIONS

Levator ani avulsion during vaginal delivery in primiparous women occurs in nearly one in every five deliveries. Delivery mode is a significant and modifiable intrapartum risk factor for this lesion. The incidence is lower in spontaneous delivery and significantly increases when an instrument is used to assist delivery, especially forceps.

Association between the side of levator Ani muscle trauma and fetal position at birth - a prospective observational study

INTRODUCTION

Trauma of the levator ani muscle (LAM) is common after vaginal birth and can most reliably be diagnosed by 3-dimensional (3D) translabial ultrasound (TLUS). Multiple risk factors are known in general, but not in association to a specific side of the body. Therefore, our aim was to evaluate different impact factors which cause LAM trauma on either side of the body or bilateral by focusing on the fetal position at birth.

MATERIAL AND METHODS

As part of a prospective cohort study between 3/2017 and 4/2019, we analyzed vaginal births of nulliparous women with singletons in vertex presentation≥36+0 gestational weeks. We evaluated their pelvic floor for hematomas, partial and complete LAM avulsions by 3D TLUS 2-4 days postpartum and searched for an association between the affected body side and different fetal, maternal and obstetrical factors.

RESULTS

71 out of 213 women (33.3%) suffered from LAM trauma - 17 (23.9%) on the right side, 20 (28.2%) on the left side and 34 (47.9%) bilateral. No association between the different evaluated factors and the affected body side could be identified, except for the quality of fetal heart rate tracing.

CONCLUSIONS

No significant impact factors of LAM trauma could be associated with a specific side of the body. Other possible mechanisms need investigation in the future, such as the time of the birth canal and the fetus to adapt to each other, including adequate time for the tissue to stretch and the fetus to rotate into the ideal position within the LAM hiatus.

EINLEITUNG

Levatormuskelverletzungen sind häufig nach Vaginalgeburten und können zuverlässig mittels translabialem 3D-Ultraschall diagnostiziert werden. Diverse Risikofaktoren sind hierfür bekannt, allerdings keine hinsichtlich der Assoziation zu einer der beiden Körperseiten. Daher war das Ziel dieser Arbeit, verschiedene Einflussfaktoren im Rahmen vaginaler Geburten zu evaluieren, welche eine Levatorverletzung auf einer der beiden Körperseiten bzw. beidseitig begünstigen, v. a. hinsichtlich der Kindsposition im Geburtskanal.

MATERIAL UND METHODIK

In einer prospektiven Kohortenstudie analysierten wir von 3/2017-4/2019 Erstgebärende mit vaginalen Einlingsgeburten aus Schädellage≥36+0 SSW. Wir evaluierten 2-4 Tage postpartal ihren Beckenboden mittels 3D-Ultraschall hinsichtlich Hämatomen sowie partiellen und kompletten Levatoravulsionen und suchten nach Assoziationen zwischen der betroffenen Körperseite und fetalen, maternalen und geburtshilflichen Einflussfaktoren.

ERGEBNISSE

Von 213 Frauen erlitten 71 (33.3%) eine Levatorverletzung - 17 (23.9%) rechtsseitig, 20 (28.2%) linksseitig und 34 (47.9%) beidseitig. Es wurden keine Assoziationen zwischen den untersuchten Einflussfaktoren und der betroffenen Körperseite gefunden, bis auf die Qualität der fetalen Herzfrequenz.

DISKUSSION

Es konnten keine signifikanten Einflussfaktoren für das Auftreten einer Levatorverletzung einer spezifischen Körperseite eruiert werden. Daher bedarf es in Zukunft der Untersuchung weiterer Mechanismen, wie der Adaptationsvorgänge von Geburtskanal und Fet und der adäquaten Zeit für das Gewebe zur notwendigen Dehnung, v. a. im Bereich der Levatoröffnung.

Prediction of levator ani muscle avulsion by genital tears after vaginal birth-a prospective observational cohort study

INTRODUCTION

Visible birth tears and levator ani muscle (LAM) trauma are common after birth. For the diagnosis of LAM trauma ultrasound evaluation is advisable. As ultrasound equipment and trained personnel are not available everywhere at all times, we aimed to evaluate whether specific overt birth tears are an indicator for LAM trauma.

METHODS

In a prospective cohort study at our center from March 2017-April 2019, we evaluated vaginal births of nulliparous women with singletons in vertex presentation ≥ 36 + 0 gestational weeks for LAM trauma by translabial ultrasound and for overt birth tears by inspection. We then calculated the association of overt birth tears with complete LAM avulsion.

RESULTS

Of 213 women, 23.9% had any kind of LAM trauma, with 14.1% being complete avulsions. In univariate analysis, solely high-grade perineal tears (OASIS) were significantly associated with complete LAM avulsions.

CONCLUSIONS

Fourteen percent of women suffered a complete LAM avulsion after vaginal birth, with OASIS being the only associated parameter of significance. The occurrence of such trauma might be an indicator for a mismatch between the size of the fetus and the structures of the birth canal, leading to birth trauma. Assessing for LAM trauma by translabial ultrasound in women with OASIS might be worthwhile.

Postpartum sexual function; the importance of the levator ani muscle

Introduction and hypothesis

Pelvic floor muscle function plays an important role in female sexual functioning. Smaller genital hiatal dimensions have been associated with sexual dysfunction, mainly dyspareunia. On the other hand, trauma of the levator ani muscle sustained during childbirth is associated with increased genital hiatus, which potentially can affect sexual functioning by causing vaginal laxity. This study aims to determine the association between levator hiatal dimensions and female sexual dysfunction after first vaginal delivery.

Methods

This is a secondary analysis of a prospective observational study. Two hundred four women who had a first, spontaneous vaginal delivery at term between 2012 and 2015 were recruited at a minimum of 6 months postpartum. Thirteen pregnant women were excluded. We analyzed the association of total PISQ-12 score, as well as individual sexual complaints (desire, arousal, orgasm and dyspareunia), with levator hiatal dimensions at rest, with maximum Valsalva and during pelvic floor muscle contraction as measured by 4D transperineal ultrasound. Statistical analysis was performed using linear regression analysis and Mann-Whitney U test.

Results

One hundred ninety-one women were evaluated at a median of 11 months postpartum. There was no significant association between total PISQ-12 score and levator hiatal dimensions. Looking at individual sexual complaints, women with dyspareunia had significantly smaller levator hiatal area and anterior-posterior diameter on maximum Valsalva. By using multivariate logistic regression analysis however we found dyspareunia was not independently associated with levator hiatal dimensions.

Conclusions

After first vaginal delivery sexual dysfunction is not associated with levator hiatal dimensions as measured by 4D transperineal ultrasound.

Malmström vacuum or Kielland forceps: which causes more damage to pelvic floor?

OBJECTIVE

To determine whether differences exist in the rate of levator ani muscle (LAM) avulsion between women who had undergone either Malmström vacuum delivery (MVD) or Kielland forceps delivery (KFD), allowing for potential confounding factors.

METHODS

This was a prospective observational study of nulliparous women undergoing instrumental delivery using Malmström vacuum extractor or Kielland forceps, at two hospital centers in Spain. Fetal head position (anterior, posterior or transverse) and fetal head station (low or mid) were assessed by ultrasound and digital examination, respectively. Avulsion was defined on tomographic ultrasound imaging as an abnormal insertion of the LAM in the three central slices from the plane of minimal hiatal dimensions.

RESULTS

In total, 414 patients were included in the study (212 MVD and 202 KFD). We observed a higher rate of LAM avulsion in the KFD group (KFD 49.5% vs MVD 32.5%; P = 0.001). When the results were evaluated according to fetal head position and station, we observed no differences in LAM avulsion. The crude odds ratio (OR) for the difference in avulsion between women in the KFD and MVD groups was 2.03 (95% CI, 1.36-3.03). However, when adjusted for duration of second stage of labor, fetal head circumference and fetal head station, the OR was no longer statistically significant (OR, 2.14 (95% CI, 0.95-4.85); P = 0.068).

CONCLUSION

When potential confounding factors are taken into account, the rate of LAM avulsion does not differ between women according to whether they have undergone KFD or MVD. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Device to predict pelvic floor integrity during vaginal delivery: an intra- and interrater reliability study of the Epi-no distensibility measurement

Objective: To determine the test-retest reliability of the pelvic floor distensibility evaluation with Epi-no^® device.Methods: Prospective, blinded observational study with 32 women pregnant from 35 gestational weeks. An Epi-no^® balloon was inflated within the pregnant woman's vagina and the maximum circumference achieved was measured using a standard metric measuring tape. Measurements were performed twice in a day by two physiotherapists in a randomized order. Intraobserver reproducibility was obtained with another evaluation 7-14 d after the initial examination. The intraclass correlation coefficient (ICC) was used to determine the intra and interrater reliability and the respective 95% confidence intervals with an alpha level of 0.05.Results: From a total of 32 included pregnant women, 28 were analyzed; they were 29.3 (±5.97) years old, were at 37 (±1.3) weeks' gestation and presented a mean Epi-no^® circumference of 20.4 (±2.4) cm. Regarding the intraobserver analysis, examiner 1 observed a maximum circumference of 20.6 (±2.6) cm in the first evaluation and 20.2 (±2.4) cm in the second evaluation, with good reliability (ICC = 0.85). Examiner 2 observed 19.7 (±2.4) cm in the first evaluation and 21.0 (±2.0) cm in the second one, with moderate reliability (ICC = 0.58). Regarding the interobserver analysis, there was good reliability on two evaluation days, with an ICC of 0.76 and 0.82, respectively.Conclusions: Epi-no^® device is a reliable device for physiotherapists to measure pelvic floor distention during pregnancy.

The correlation between the type of forceps application and the rate of levator ani muscle avulsion: A prospective cohort study

OBJECTIVES

The association between the use of forceps and levator ani muscle (LAM) avulsion seems to be clear-cut. However, whether the lesion is due to the mechanical trauma yielded by the instrument or to the intrinsic complexity of this type of delivery, is yet to be determined. This study aims at determining the difference in LAM avulsion rate between Kielland rotational forceps and non-rotational forceps.

STUDY DESIGN

Prospective observational study with 94 nulliparous women with forceps-assisted deliveries (FD) between July 2015 and January 2016. 3D-TpUS was performed 6 months after every patient's delivery, during which LAM avulsion, and levator hiatus area and anteroposterior and transverse diameters were assessed.

RESULTS

A total of 89 nulliparous were studied, comprising 27 rotational-FD, and 62 non-rotational-FD. No differences in obstetric, intrapartum, or neonatal characteristics were observed between study groups. There were no statistically significant differences in the presence of avulsion between cases of rotational forceps (44.4% vs 35.5%, OR: 1.5 [0.6-3.6]), correction of asinclitism of the fetal head (34.4% vs. 40.4% OR: 0.8 [0.3-1.9]) or station (midforceps: 32.8% vs low forceps: 50.0% OR: 2.0 [0.8-5.1]).

CONCLUSIONS

We have not observed differences in the LAM-avulsion rate between rotational forceps and non-rotational forceps performed by highly experienced personnel in instrumental deliveries.

Influence of the disengagement of the forceps on levator ani muscle injuries in instrumental delivery: A multicenter study

INTRODUCTION

Forceps use is the main risk factor for levator ani muscle (LAM) injuries. We believe that the disengagement of the forceps branches before delivery of the fetal head could influence LAM injuries, so we aimed to determine the influence of the disengagement of the forceps on the occurrence of LAM avulsion during forceps delivery.

MATERIAL AND METHODS

A prospective, observational, multicenter study was conducted with 261 women who underwent forceps delivery. The women were classified according to whether the branches of the forceps had been disengaged before delivery of the fetal head. LAM avulsion was defined using a multislice mode (3 central slices).

RESULTS

In all, 255 women completed the study (160 without disengagement and 95 with disengagement). LAM avulsions were observed in 37.9% of women in the group with disengagement and in 41.9% of women in the group without disengagement. The crude OR (without disengagement vs with disengagement) for avulsion was 0.90 (95% CI 0.49-1.67, P = 0.757) and an adjusted OR of 0.82 (95% CI 0.40-1.69, P = 0.603).

CONCLUSIONS

We did not observe a statistically significant reduction in the LAM avulsion rate with disengagement of the forceps branches before delivery of the fetal head.

Levator ani muscle morphology and function in women with obstetric anal sphincter injury

OBJECTIVES

To estimate the prevalence of, and explore the risk factors for, levator ani muscle (LAM) injury in women with clinically diagnosed obstetric anal sphincter injury (OASI). The secondary aim was to assess the association between LAM injury and pelvic floor muscle contraction, anal incontinence (AI) and urinary incontinence (UI) in women with OASI.

METHODS

This was a cross-sectional study of 250 women with OASI, recruited between 2013 and 2015 from a tertiary referral center at Croydon University Hospital, UK. AI symptoms were assessed using the modified St Mark's incontinence score and UI was assessed using the International Consultation on Incontinence modular Questionnaire for Urinary Incontinence - Short Form. All participants underwent three/four-dimensional transperineal ultrasound at rest and on maximum pelvic floor muscle contraction. Major LAM injury was defined as a unilateral or bilateral defect in all three central slices on tomographic ultrasound imaging. Muscle contraction was assessed using the modified Oxford scale (MOS) and measured on ultrasound as the proportional change in the anteroposterior (AP) levator hiatal diameter between rest and contraction. Multivariable logistic regression analysis was used to study risk factors for LAM injury. Differences in contraction and AI and UI symptoms between women with intact and those with injured LAM were studied using multivariable ANCOVA and the Mann-Whitney U-test.

RESULTS

Of the 248 women with OASI for whom ultrasound volumes of adequate quality were available, 29.4% were found to have major LAM injury. The prevalence of LAM injury was 23.6% after normal vaginal delivery and 40.2% after operative vaginal delivery (adjusted odds ratio, 4.1 (95% CI, 1.4-11.9); P = 0.01). LAM injury was associated with weaker pelvic floor muscle contraction, with an adjusted mean difference for proportional change in AP diameter of 5.0 (95% CI, 3.0-6.9) and MOS of 0.6 (95% CI, 0.3-0.9) (P < 0.001 for both). AI and UI symptom scores were similar between women with intact and those with injured LAM.

CONCLUSIONS

Operative vaginal delivery was a risk factor for LAM injury in women with OASI. LAM injury was associated with weaker pelvic floor muscle contraction. Special attention is recommended for women with OASI and LAM injury, as they are at high risk for future pelvic floor disorders. The benefits of implementation of an intensive, focused and structured pelvic floor rehabilitation program need to be evaluated in these women. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

A comparable rate of levator ani muscle injury in operative vaginal delivery (forceps and vacuum) according to the characteristics of the instrumentation

INTRODUCTION

Forceps delivery is associated with a high rate of levator ani muscle (LAM) trauma (avulsion) at 35%-65% whereas data on avulsion rates after vacuum delivery vary greatly. Nevertheless, a common characteristic of all previous studies carried out to evaluate the association between instrumental deliveries (forceps and vacuum) and LAM avulsion, is the fact that characteristics of the instrumentation have not been described or evaluated. The objective of this study is to compare the rate of LAM avulsion between forceps and vacuum deliveries according to the characteristics of the instrumentation.

MATERIAL AND METHODS

Prospective, observational study, including 263 nulliparous women, who underwent an instrumental delivery with either Malmström vacuum or Kielland forceps. The characteristics of the instrumentation, position (anterior position and other position) and height of the fetal head at the moment of instrumentation (low instrumentation [vertex at +2 station] and mid-instrumentation [head is involved but leading part above +2 station]) were assessed. Evaluation of LAM avulsion was performed at 6 months postpartum by three-/four-dimensional transperineal ultrasound. Using the multi-view mode, a complete avulsion was diagnosed when the abnormal muscle insertion was identified in all three central slices, that is, in the plane of minimal hiatal dimensions and the 2.5-mm and 5.0-mm slices cranial to this one. To detect a 30% or 15% difference in the LAM injury rate, with 80% power and 5% α-error, we needed, respectively 42 and 99 women per study group.

RESULTS

In all, 263 nulliparous individuals have been evaluated (162 vacuum deliveries, 101 forceps deliveries). Instrumentation in an occipito-anterior position was more frequent in vacuum deliveries (75.3% vs 56.4%, P = .002), whereas other positions were more frequent in the forceps deliveries group (24.7% vs 43.6%). No statistically significant differences were noted regarding the height of the fetal head at the moment of instrumentation. No statistically significant differences were found in the presence of LAM avulsion (41.4% vs 38.6%) between vacuum and forceps deliveries. The univariate analysis of the crude odds ratio was 1.17, 95% CI 0.67-1.98, P = .70 for the avulsion of the LAM and the multivariate of the adjusted OR 0.90, 95% CI; 0.53-1.55, P = .71.

CONCLUSIONS

We consider that, in our population, LAM avulsion rate should not be a factor taken into account when choosing the type of instrumentation (Malmström vacuum or Kielland forceps) in an operative delivery.

Association between pelvic floor muscle trauma and contraction in parous women from a general population

OBJECTIVE

To study possible associations between pelvic floor muscle contraction, levator ani muscle (LAM) trauma and/or pelvic organ prolapse (POP) ≥ Stage 2 in parous women recruited from a general population.

METHODS

This was a secondary analysis of data from a cross-sectional study of 608 parous women from a general population examined using the POP quantification system (POP-Q) and three-dimensional/four-dimensional transperineal ultrasound for identification of LAM macrotrauma (avulsion) and microtrauma (distension of levator hiatal area > 75^th percentile on Valsalva maneuver). Muscle contraction was assessed using the modified Oxford scale (MOS), perineometry and ultrasound measurement of proportional change of anteroposterior hiatal diameter and levator hiatal area at rest and on pelvic floor muscle contraction. The Mann-Whitney U-test was used to study associations between pelvic floor muscle contraction, LAM trauma and POP.

RESULTS

Women with macrotrauma (n = 113) had significantly weaker median pelvic floor muscle contraction, as measured using MOS and perineometry, than did women with an intact LAM (n = 493) (contraction strength was 1.5 (range, 0.0-5.0) vs 3.5 (range, 0.0-5.0) on MOS, and vaginal squeeze pressure was 15.0 (range, 0.0-78.0) cmH₂ O vs 28.0 (range, 0.0-129.0) cmH₂ O on perineometry; P < 0.001). This was also demonstrated by ultrasound measurement, with a proportional change in hiatal area of 19.9% (range, 4.1-48.0%) vs 34.0% (range, 0.0-64.0%) (P < 0.001) and proportional change in anteroposterior diameter of 16.2% (range, -5.7 to 42.6%) vs 26.0% (range, -3.4 to 49.4%) (P < 0.001). No statistically significant difference between women with (n = 65), and those without (n = 378), microtrauma was found after excluding women with macrotrauma. Women with POP had weaker muscle contraction than those without; in those with POP-Q ≥ 2 (n = 275) compared with those with POP-Q < 2 (n = 333), muscle contraction strength was 3.0 (range, 0.0-5.0) vs 3.5 (range, 0.0-5.0) on MOS, vaginal squeeze pressure was 21.0 (range, 0.0-98.0) cmH₂ O vs 28.0 (range, 3.0-129.0) cmH₂ O on perineometry, proportional change in hiatal area was 29.6% (range, 0.0-60.9%) vs 33.8% (range, 0.0-64.4%) and proportional change in anteroposterior diameter was 22.8% (range, -5.7 to 49.4%) vs 25.7% (range, -3.4 to 49.4%) (P < 0.001 for all).

CONCLUSIONS

LAM macrotrauma was associated with weaker pelvic floor muscle contraction measured using palpation, perineometry and ultrasound. Women with POP had weaker contraction than did women without POP. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Delivery mode and the risk of levator muscle avulsion: a meta-analysis

INTRODUCTION AND HYPOTHESIS

Female pelvic organ prolapse (POP) is a common condition, with a lifetime risk for surgery of 10-20%. Pregnancy and childbirth are the commonest modifiable risk factors for POP, and avulsion of the levator ani muscle is likely to be an etiological factor. Avulsion is more common in instrumental delivery. However, we were unable to identify a meta-analysis on this issue. Our aim was to perform a systemic review and quantitative meta-analysis of the prevalence of avulsion relative to delivery mode.

METHODS

Four electronic databases (MEDLINE, PubMed, Embase, and Google Scholar) were searched for studies published between 1991 and 1 October 2018 without language restrictions.

RESULTS

Twenty studies met inclusion criteria, and 14 were prospective. Seventeen used sonographic techniques; three were magnetic resonance (MR) studies. For this review, three comparisons were performed: forceps vs. vacuum (9 studies), forceps vs. normal vaginal delivery (NVD) (12 studies), and vacuum vs. NVD (12 studies). The first meta-analysis showed an increased risk for avulsion following forceps compared with vacuum, with an odds ratio (OR) of 4.57 and confidence interval (CI) 3.21-6.51, p < 0.001. The second showed an increased risk for avulsion following forceps compared with NVD, with an OR of 6.94 (4.93-9.78), p < 0.001. The third showed no significant increased risk for avulsion following vacuum compared with NVD, with an OR of 1.31 (1.00-1.72), p = 0.051.

CONCLUSIONS

Forceps is a strong risk factor for avulsion, with an OR of 6.94 (4.93-9.78) compared with NVD and an OR of 4.57 (3.21-6.51) compared with vacuum birth.

Association of levator injury and urogynecological complaints in women after their first vaginal birth with and without mediolateral episiotomy

BACKGROUND

Pelvic organ prolapse is a common health problem in women and has a negative influence on quality of life. A major cause of pelvic organ prolapse is levator injury.

OBJECTIVE

The objective of the study was to evaluate the association of mediolateral episiotomy with levator injury (levator avulsion, ballooning, or combined) and urogynecological complaints.

STUDY DESIGN

A prospective observational cohort study was performed in 204 primiparous women with a spontaneous vaginal delivery without anal sphincter tear in a general hospital between 2012 and 2015. One hundred three of these women had had a mediolateral episiotomy. Validated urogynecological questionnaires and transperineal 3-dimensional/4-dimensional ultrasound were completed after delivery. Outcome measures were levator avulsion, ballooning (hiatal area of more than 25 cm²), and urogynecological questionnaire scores. Statistical analysis was performed using univariate and multiple logistic regression analysis.

RESULTS

The median time at investigation after vaginal delivery was 13 months (range 6-33). Levator injury (avulsion, ballooning, or combined) was identified in 35 of the 103 women who had undergone mediolateral episiotomy (40.0%) and 33 of the 101 women without episiotomy (32.7%) (P = .69). No differences were found in the incidence of levator avulsion 27 (26.7%) vs 23 (22.8%) (P = .53) or in levator ballooning (20 [19.4%] vs 23 [22.8%] (P = .58) between both groups. There was an association between longer duration of the second stage of labor and the incidence of levator avulsion (odds ratio, 1.24 [95% confidence interval, 1.01-1.52]). Nonocciput anterior fetal position increased the risk of levator ballooning and levator injury (odds ratio, 10.19 [95% confidence interval, 1.89-54.91] and odds ratio, 12.16 [95% confidence interval, 1.41-104.38], respectively). No differences in urogynecological complaints were found.

CONCLUSION

Mediolateral episiotomy is not associated with the occurrence of levator injury or urogynecological complaints in women with a spontaneous vaginal delivery who did not obtain an anal sphincter injury. Levator injury was associated with a prolonged second stage of labor and a nonocciput anterior fetal position.

Prevalence of Maternal Birth Trauma in Nepali Women

OBJECTIVES

Pelvic organ prolapse is very common among women in Nepal, especially uterine prolapse. This would suggest a high rate of levator trauma, which is a strong predictor of such prolapse in the Western world. Hence, we decided to study the prevalence of maternal birth trauma in Nepali women.

METHODS

In November 2016, we offered an interview, clinical examination, and 4-dimensional translabial sonography to women attending a gynecology clinic. Of 129 women seen, 5 were excluded due to previous pelvic surgery. Translabial sonography volume data sets were obtained and analyzed by tomographic imaging for levator ani and anal sphincter trauma at a later date, blinded against all clinical data.

RESULTS

Mean age was 39 (21-74) years, median vaginal parity was 2 (0-9), mean age at first delivery 21 (14-40). Seventeen (14%) had not given birth vaginally; of these, 14 (11%) delivered by cesarean only, and 3 (2%) were nulliparous. Tomographic assessment for levator avulsion and anal sphincter trauma was possible in 124 women and performed as previously described. We found 2 (2%) unilateral avulsions and significant external anal sphincter defects in another 2 women.

CONCLUSIONS

Levator and anal sphincter trauma are significantly less prevalent in Nepali women in comparison to Western populations. This is intriguing, especially in view of the high prevalence of prolapse in Nepali women.

Correlation Between Delivery Mode and Pelvic Organ Prolapse Evaluated by Four-Dimensional Pelvic Floor Ultrasonography

BACKGROUND This study explored symptoms and signs of pelvic organ prolapse (POP) evaluated by 4-dimensional pelvic floor ultrasonography and analyzed the relationship between delivery mode and POP. MATERIAL AND METHODS A total of 578 women who underwent 4-dimensional transperineal ultrasound were enrolled in this study. Obstetric history together with other clinical information were gathered from clinical questionnaires and gynecologists. Patients were thereafter classified into 4 groups: women with normal vaginal delivery, women with forceps delivery, women with cesarean, and nullipara women. We assessed symptoms and signs of POP among these 4 groups by use of 2 evaluation methods. The first method was clinical assessment applying International Continence Society (ICS) pelvic organ prolapse quantification (POP-Q). The second method was the use of ultrasonography in the quantification of anterior, middle, and posterior compartment prolapse. RESULTS Nulliparae women exhibited the lowest probability of POP (POP-Q: cystocele of 15.6%, uterine prolapse of 11.1%, rectocele of 20.0%; ultrasound exam: 6.7%, 8.9%, 13.3% in sequence), while women with forceps delivery had the highest probability of POP (POP-Q: 59.6%, 50.8%, 63.2% in sequence; ultrasound exam: 45.6%, 52.6%, 42.1% in sequence). Regarding the correlation between POP and delivery mode, the adjusted odds ratio was 2.40 (95%CI: 1.301~4.590) and 3.20 (95%CI: 1.651~6.121) in the normal vaginal delivery group and forceps group, respectively, compared with the cesarean group. CONCLUSIONS Four-dimensional pelvic floor ultrasonography can be used as a preferred method in evaluating POP. Regarding the relationship between delivery mode and POP, there is a significant correlation between vaginal delivery and POP.

Maternal and neonatal outcomes from a comparison of spontaneous and directed pushing in second stage

AIM

To compare the effect of directed or spontaneous maternal pushing effort on duration of second stage labour, perineal injury and neonatal condition at birth.

METHODS

A retrospective cross-sectional design provided data for term women with singleton, cephalic presentation experiencing a non-operative vaginal birth without regional analgesia from January 2011 to December 2017 (n=69,066) Participants matching the inclusion criteria (n=19,212) were grouped based upon spontaneous or directed pushing. Propensity score matching was used to select equally sized cohorts of similar characteristics (n=10,000). The associations with outcomes of interest were estimated using odds ratios obtained by multivariate analysis.

FINDINGS

Directed pushing was associated with a longer duration of second stage labour for nulliparous (mean 14.4min [12.0-16.8]) and multiparous (mean 8.0min [6.8-9.2]) women, and an increased risk of prolonged 2nd stage of labour in multiparous women. The use of episiotomy in the directed pushing group was significantly higher both prior to and following PS matching and adjustment. Directed pushing was also associated with an significantly increased risk of neonatal resuscitation and nursery admission. There was no difference in rates of Apgar <7 recorded at 5min of age.

CONCLUSION

Directed pushing is associated with an increased duration of second stage labour and risk of adverse neonatal outcomes. Our study suggests that in the absence of regional analgesia women should be supported to follow their own expulsive urges.

Can we predict levator ani muscle avulsion in instrumental deliveries through intrapartum transperineal ultrasound?

Introduction: To determine whether intrapartum translabial ultrasound (ITU) is useful for the prediction of levator ani muscle (LAM) avulsions in instrumental deliveries (vacuum and forceps). Materials and methods: Prospective, observational study, including (1/2016 - 5/2016) 77 nulliparous women, with singleton pregnancies of ≥37 weeks of gestation and with cephalic presentation, who required vacuum or forceps instrumentation to complete the delivery. The ITU parameters evaluated were Angle of Progression (AoP), Progression Distance (PD), Head Direction (HD), and Midline Angle (MLA), both at rest and with maternal push. Evaluation of LAM avulsion was performed at 6 months postpartum with 3-4D transperineal ultrasound. Complete avulsion was defined as an abnormal insertion of LAM in the lower pubic branch identified in all three central slices. Results: Data from 48 nulliparous women were finally included in the study (34 vacuum and 14 forceps). We observed no difference in obstetric parameters between the two study groups (group with avulsion of LAM -14 cases, 29.2% - and group without avulsion of LAM -34 cases, 70.8%). The "LAM avulsion group" had an AoP and a PD of 136.7 ± 22.4 and 43.5 ± 15.6, respectively, versus 141.6 ± 21.3 and 47.2 ± 16.8 recorded in the group without avulsion (NS), respectively. We obtained a ROC curve for AoP and PD with a push of 0.66 (95% CI, 0.28-1.00) and 0.57 (95% CI, 0.39-0.75), respectively. Conclusions: ITU is not a useful technique to predict the occurrence of LAM avulsion in instrumental deliveries with vacuum or forceps.

Maternal birth trauma: why should it matter to urogynaecologists?

PURPOSE OF REVIEW

There is increasing awareness of the importance of intrapartum events for future pelvic floor morbidity in women. In this review, we summarize recent evidence and potential consequences for clinical practice.

RECENT FINDINGS

Both epidemiological evidence and data from perinatal imaging studies have greatly improved our understanding of the link between childbirth and later morbidity. The main consequences of traumatic childbirth are pelvic organ prolapse (POP) and anal incontinence. In both instances the primary etiological pathways have been identified: levator trauma in the case of POP and anal sphincter tears in the case of anal incontinence. As most such trauma is occult, imaging is required for diagnosis.

SUMMARY

Childbirth-related major maternal trauma is much more common than generally assumed, and it is the primary etiological factor in POP and anal incontinence. Both sphincter and levator trauma can now be identified on imaging. This is crucial not only for clinical care and audit, but also for research. Postnatally diagnosed trauma can serve as intermediate outcome measure in intervention trials, opening up multiple opportunities for clinical research aimed at primary and secondary prevention.

Longitudinal pelvic floor biometry: which factors affect it?

OBJECTIVES

To evaluate pelvic floor biometry of women 3-5 years after their first delivery. The effect of a subsequent delivery and the mode of delivery on pelvic floor biometry were also studied.

METHODS

Three-hundred and twenty-eight women who had been examined by translabial ultrasound during their first singleton pregnancy and at 8 weeks and 1 year postpartum, were invited for a follow-up 3-5 years later. The positions of the bladder neck, cervix, anorectal junction and hiatal area (HA) were evaluated using translabial ultrasound. The effects of parity, mode of delivery and levator ani muscle avulsion were studied.

RESULTS

A total of 240 women completed the study. Of these, 179 had one or more vaginal deliveries (VD) (VD-only group), 52 had one or more Cesarean sections (CS) (CS-only group) and nine had both VD and CS at follow-up. The mean interval between the first delivery and follow-up was 3.8 years. A significantly lower bladder neck and anorectal junction on Valsalva, a lower cervix at rest, on Valsalva and pelvic floor muscle contraction, and a greater HA were observed in the VD-only group at follow-up, compared with findings at 1 year of follow-up or in the first pregnancy. The findings were similar in the CS-only group, except without a lower anorectal junction on Valsalva. Compared with the primiparous VD-only group, a greater HA at rest was observed in the multiparous VD-only group (P = 0.027). The VD-only group had a greater HA than the CS-only group.

CONCLUSIONS

At 3-5 years after first delivery, a lower bladder neck, cervix and anorectal junction, and a greater HA were observed compared with findings in the first trimester and at 1 year of follow-up, regardless of parity or mode of delivery. Women with two or more VDs had a greater HA compared with those who had only one VD, and women with at least one VD had a greater HA compared with those who delivered by CS only. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

New Measures for Predicting Birth-Related Pelvic Floor Trauma

OBJECTIVES

The aim of this study was to establish the predictive role of obstetric variables for obstetric outcomes and birth related levator ani muscle (LAM) trauma.

METHODS

In this prospective study, women underwent 3-dimensional pelvic floor ultrasound at their first appointment at 36 weeks and also 3 months postpartum. The measurements included minimal levator hiatus circumference (MLHC) and the ratio of fetal head circumference to MLHC = head-induced stretch ratio (HISR) as an indicator of the discrepancy between passage and passing canal. To derive the true impact of baby's mass on the levator ani musculature, we devised the levator ani stretch ratio (LASR), which was calculated by multiplying the HISR and the baby's weight.

RESULTS

Data set of 173 women was available for analysis. Mean HISR and LASR values were statistically different across all binary outcome categories, with 1 exception for HISR and levator ani injury. The odds ratios for LASR indicated positive and statistically significant associations with all obstetric outcomes examined. The probability of the LASR correctly classifying those with the adverse obstetric outcome, as estimated by the area under the curve, ranged from 0.64 to 0.80 with the strongest discriminatory ability observed for severe LAM trauma.

CONCLUSIONS

Fetal head circumference/mother MLHC ratio (HISR) is associated with longer length of second stage of labor, assisted delivery, and increased severity of perineal trauma. Similar associations were observed for LASR, but in addition, LASR had good discriminatory ability to identify severe LAM trauma.

Recent Advances in Understanding Pelvic-Floor Tissue of Women With and Without Pelvic Organ Prolapse: Considerations for Physical Therapists

Pelvic organ prolapse is a fairly common condition that imposes significant symptoms, diminished quality of life, social burden, financial expense, and surgical risk on women. As evidence supporting the benefit of pelvic-floor muscle training in nonsurgical management of pelvic organ prolapse grows, physical therapists are becoming a provider of choice interacting with women affected by pelvic organ prolapse. This perspective article will review recent research on tissue characteristics of 3 key components of pelvic organ support: skeletal muscle, ligament, and vaginal wall. This information will be summarized as implications for physical therapists. An improved understanding of pelvic-floor tissue in women with and without pelvic organ prolapse will provide a more comprehensive appreciation of the interaction of multiple systems in the disorder.

Intrapartum predictors of maternal levator ani injury

INTRODUCTION

Damage to the pelvic floor during vaginal childbirth is common, and may take the form of levator avulsion or irreversible overdistension of the levator hiatus (microtrauma). Such trauma is a major risk factor for pelvic organ prolapse later in life. In this study we aimed to identify intrapartum risk factors for levator trauma.

MATERIAL AND METHODS

This is a retrospective analysis of data obtained in two perinatal studies on primiparous women. Between 2005 and 2014, 1148 women carrying an uncomplicated singleton pregnancy in the late third trimester were seen for 4D pelvic floor ultrasound and an interview. They were invited for a repeat assessment at three months postpartum.

RESULTS

Of 1148 women, 871 (76%) returned for assessment at a mean of five months postpartum. The datasets of 844 women were analyzed due to missing data or concurrent pregnancy in 27. In all, 452 (54%) had a normal vaginal delivery, 102 (12%) a vacuum, 55 (6%) a forceps, and 235 (28%) a cesarean section. On multivariate analysis forceps, length of second stage and obstetric anal sphincter tears were significantly associated with levator avulsion. There were no significant predictors identified for irreversible overdistension.

CONCLUSIONS

The use of forceps, a prolonged second stage, and obstetric anal sphincter tears were associated with levator avulsion. There were no associated intrapartum predictors for hiatal overdistension.

Is obstetric anal sphincter injury a risk factor for levator ani muscle avulsion in vaginal delivery?

OBJECTIVE

To analyze whether women who sustain obstetric anal sphincter injury (OASI) in their first vaginal delivery have a higher incidence of levator ani muscle (LAM) avulsion than do women without OASI.

METHODS

We conducted a prospective observational cohort study of 80 primiparous women who gave birth at our tertiary obstetric unit between September 2011 and July 2013. The women were divided into two groups: women diagnosed with OASI during vaginal delivery (n = 40) and women without OASI (n = 40), matched by mode of delivery and newborn birth weight. Four-dimensional (4D) transperineal ultrasound was performed in all participants at 6-12 months after delivery to assess for integrity or avulsion of the LAM. Ultrasound images were evaluated by two observers who were blinded to group assignment and clinical data. Interobserver agreement was assessed to determine the reproducibility of 4D transperineal ultrasound for diagnosing LAM avulsion.

RESULTS

We found no statistically significant differences between the two groups. The incidence of LAM avulsion was 24.3% in the OASI group and 34.2% in the control group (P = 0.448). Interobserver agreement in the diagnosis of LAM avulsion in the study population using 4D transperineal ultrasound was 89.5%, with a kappa index of 0.76.

CONCLUSIONS

Our findings do not support OASI as a risk factor for LAM avulsion. Prospective studies in larger populations are needed to establish the biomechanical relationships of the pelvic floor structures involved in vaginal delivery. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

The Epidemiology of Pelvic Floor Disorders and Childbirth: An Update

Using a lifespan model, this article presents new scientific findings regarding risk factors for pelvic floor disorders (PFDs), focusing on the role of childbirth in the development of single or multiple coexisting PFDs. Phase I of the model includes predisposing factors, such as genetic predisposition and race. Phase II includes inciting factors, such as obstetric events. Prolapse, urinary incontinence (UI), and fecal incontinence (FI) are more common among vaginally parous women, although the impact of vaginal delivery on risk of FI is less dramatic than prolapse and UI. Phase III includes intervening factors, such as age and obesity.