Can levator avulsion be predicted antenatally?

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.

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.

Diagnosis of maternal birth trauma by pelvic floor ultrasound

BRIEF SUMMARY

Maternal somatic birth trauma due to vaginal delivery is more common than generally assumed and an important cause of future morbidity. Maternal birth trauma may involve both psychological and somatic morbidity, some of it long-term and permanent. Somatic birth trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle, termed 'avulsion'. This review will focus on recent developments in the imaging diagnosis of maternal birth trauma, discuss the most important risk factors and strategies for primary and secondary prevention. Translabial and exo-anal ultrasound allow the assessment of maternal birth trauma in routine clinical practice and enable the use of levator avulsion and anal sphincter trauma as key performance indicators of maternity services. This is likely to lead to a greater awareness of maternal birth trauma amongst maternity caregivers and improved outcomes for patients, not the least due to an increasing emphasis on patient autonomy and informed consent in antenatal and intrapartum care.

Assessment of Pelvic Floor Disorders due to the Gestational Diabetes Mellitus Using Three-Dimensional Ultrasonography: A Narrative Review

Gestational diabetes mellitus (GDM)is an entity with evolving conceptual nuances that deserve full consideration. Gestational diabetes leads to complications and adverse effects on the mother's and infants' health during and after pregnancy. Women also have a higher prevalence of urinary incontinence (UI) related to the hyperglycemic status during pregnancy. However, the exact pathophysiological mechanism is still uncertain. We conducted a narrative review discussing the impact of GDM on the women's pelvic floor and performed image assessment using three-dimensional ultrasonography to evaluate and predict future UI.

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?

Levator plate descent angle in pelvic floor disorders

BACKGROUND

The levator plate descent angle (LPDA) quantifies the levator plate position with reference to the pubic bone and perineal body at rest. Unfortunately, research on this notable new parameter is lacking, but it is clear that levator ani deficiency (LAD) will undermine the fundamental role of the levator ani muscle (LAM) in organ support. The aim of this study was to establish the relationship between the LPDA and LAD in patients with pelvic floor disorders.

METHODS

This retrospective study was conducted at Seoul Songdo Hospital, Korea between August 2019 and August 2020 on women with symptoms of pelvic floor disorder such as urinary incontinence, constipation, and fecal incontinence. In all cases, three-dimensional pelvic floor ultrasound was performed for LAD scoring, minimal levator hiatus, and LPDA evaluation. We evaluated LAD using a scoring system that graded levator injury according to the insertion point of each subdivision scored unilaterally. For the entire LAM group, a cumulative LAD score that ranged between 0 and 18 was possible. Scores were categorized as mild (0-6 points), moderate (7-12 points), and severe (13-18 points) deficiency RESULTS: A total of 93 patients were included in the study (mean age 65.89 ± 11.12 [range, 34-86] years). Thirteen participants had mild LAD scores (14.0%), 42 had moderate LAD scores (45.2%), and 38 had severe LAD scores (40.9%). There was a significant difference in mean age (59.23 ± 12.55 years vs. 64.43 ± 10.03 vs. 69.79 ± 10.55 years, p = 0.005) and mean parity (1.85 ± 0.90 vs 2.48 ± 1.15 vs 2.76 ± 1.10, p = 0.038) of patients between groups. There was also a significant difference in the mean Wexner incontinence score (7.14 ± 3.63 vs 7.24 ± 5.76 vs 11.41 ± 5.54, p = 0.028) and in the mean fecal incontinence quality of life (FIQOL) score (12.91 ± 3.11 vs 14.10 ± 3.87 vs 10.41 ± 3.65, p = 0.014). The mean value of the LPDA in the group with mild LAD scores was 14.65° (SD ± 3.54) and in the group with moderate LAD scores was 9.66° (SD ± 3.36). In the group with severe LAD scores, the mean LPDA was 1.83° (SD ± 4.71). The mean value for minimal levator hiatus (MLH) area in the mild LAD score group was 14.16cm² (SD ± 2.72), that in the moderate LAD score group was 15.82cm² (SD ± 2.30), and that in the severe LAD score group was 17.99cm² (SD ± 2.81). There were significant differences between the three groups both in decreasing LPDA (p < 0.001) and increasing MLH (p < 0.001). There was a negative correlation between the LAD score and LPDA and the Pearson correlation coefficient was -0.528 (moderate correlation). There was a positive correlation between the LAD score and MLH, and the Pearson correlation coefficient was 0.303 (weak correlation).

CONCLUSIONS

The LAD score and LPDA have a moderate negative correlation. In patients with severe pelvic floor symptoms and extensive LAM injury, high LAD scores and low LPDA results were confirmed. In the treatment of patients with pelvic floor disorders, the LPDA seems to be a very useful parameter in determining the severity of structural defects.

Has the prevalence of levator avulsion after forceps delivery changed over the last six decades? A retrospective study in a urogynaecological population

OBJECTIVE

Forceps delivery is associated with a higher risk of maternal birth trauma. It is speculated that it is due to sub-optimal use of forceps in inexperienced hands. The aim of this study was to determine the association between time of forceps birth and prevalence of levator avulsion over the last six decades.

STUDY DESIGN

This was a retrospective analysis of datasets of women with a history of forceps delivery, seen at a tertiary urogynaecological centre between January 2014 and August 2018. They had undergone a standardized interview, clinical examination and four-dimensional translabial ultrasound. Archived imaging data was reviewed for levator avulsion offline at a later date, blinded against all clinical data. Associations between levator avulsion, maternal age at first vaginal birth, the weight of the first vaginally born baby, and time since forceps delivery categorised by decade were tested by univariable analysis. Factors found to be significant on univariable analysis were included in a multivariable logistic regression model to test the association between prevalence of levator avulsion and time of forceps delivery while controlling for confounders.

RESULTS

In total, 2026 patients were seen during the study period. Among them 511 (25.2%) had a history of forceps delivery. Fourteen volume datasets were incomplete or missing, leaving 497 complete datasets for analysis. Mean age at presentation was 58 ± 12 years (23-91). Mean body mass index was 29 ± 6 kg/m². Mean age at first delivery was 25 ± 5 years. Mean birth weight of the first vaginal birth was 3454 ± 557 g. 457 women (92%) had had one forceps delivery, 31 had two forceps deliveries (6%) and 9 had three forceps deliveries (2%). Mean time interval between forceps delivery and assessment was 32 ± 13 years (0.3-64.8). 229 women (46%) were diagnosed with levator avulsion. The prevalence of avulsion after forceps increased significantly from 34% to 56% between 1950 and 2017 (P = 0.04). However this difference became insignificant when controlling for maternal age at 1st vaginal delivery and birth weight.

CONCLUSIONS

We found no evidence of a changed prevalence of levator avulsion at forceps delivery over the last 67 years.

Rotational forceps: a retrospective study evaluating anatomical and functional consequences for the pelvic floor

INTRODUCTION AND HYPOTHESIS

The use of Kielland's rotational forceps is considered to involve greater technical difficulty and may be associated with a higher rate of pelvic floor trauma. Our main objective was to evaluate the association between avulsion of the levator muscle and rotational and non-rotational forceps.

METHODS

This was an observational study carried out at a tertiary hospital that recruited singleton cephalic vaginally primiparous women with previous Kielland's forceps delivery between March 2012 and May 2017. Patients were retrieved from a local database, contacted consecutively and blinded to all clinical data. Power calculations determined a sample of n = 160 patients. All women underwent a urogynecological interview, clinical examination and 4D translabial ultrasound (TLUS). The 4D TLUS volumes were stored and analyzed offline by an experienced ultrasound examiner who was blinded to all clinical data.

RESULTS

A total of 165 patients were available for analysis. Rotational forceps accounted for 27.3% (45 out of 165) of the study sample. Avulsion was present in 41.8% (69 out of 165) of all forceps deliveries. On multivariate analysis, rotational forceps was associated with avulsion, with an adjusted odds ratio (OR) of 2.57 (CI 95% 1.20-5.62, p = 0.016). Body mass index at the beginning of gestation was found to be a protective factor, with an adjusted OR of 0.918 (CI 95% 0.847-0.986, p = 0.025).

CONCLUSION

Rotational forceps is associated with a higher avulsion rate than non-rotational forceps, with an adjusted OR of over 2.5. Obstetricians need to consider the potential long-term consequences of performing a rotational forceps for mothers.

Ultrasound imaging of maternal birth trauma

INTRODUCTION AND HYPOTHESIS

The term 'maternal birth trauma' has undergone substantial changes in meaning over the last 2 decades. Leaving aside psychological morbidity, somatic trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle. This review covers diagnosis of maternal birth trauma by translabial ultrasound imaging.

METHODS

Narrative review.

RESULTS

Tomographic imaging of pelvic structures with the help of 4D ultrasound, used since 2007, has allowed international standardization and seems to be highly reproducible and valid for the diagnosis of OASI and levator avulsion.

CONCLUSIONS

Translabial and exo-anal ultrasound allows the assessment of maternal birth trauma in routine clinical practice and the utilization of avulsion and sphincter trauma as key performance indicators of maternity services. It is hoped that this will lead to a greater awareness of maternal birth trauma among maternity caregivers and improved outcomes for patients, both in the short term and in the decades to come.

The Prevalence of Pelvic Floor Hematoma After Vaginal Delivery

OBJECTIVE

The goal of this study was to evaluate differences in levator ani hematoma formation within 3 days of delivery between adult women after their first vaginal delivery and adult women who have had multiple vaginal deliveries.

METHODS

This was a cross-sectional study at a single institution from 2013 to 2015 using a high-resolution endovaginal ultrasound transducer to identify postvaginal delivery hematoma formation. Logistic regression was used to examine the association between hematoma formation and vaginal parity while considering potential confounders including induction, vaginal operative delivery, vaginal birth after cesarean, fetal weight, fetal head circumference, race and ethnicity, body mass index, age at delivery, gestational age, and length of second-stage labor.

RESULTS

Ninety women (46 vaginal-primiparous; 44 vaginal-multiparous) were included in this study. After adjusting for oxytocin use, length of second-stage labor, and body mass index, the odds of pelvic floor hematoma of 1000 mm3 or greater were 2.93 (95% confidence interval, 0.78-10.91) times greater in women after their first vaginal delivery compared with women with a history of multiple vaginal deliveries. The adjusted odds of pelvic floor hematoma of 1500 mm3 or greater were 6.02 (95% confidence interval, 1.09-33.24) times greater in vaginal-primiparous compared with vaginal-multiparous women.

CONCLUSIONS

Although the prevalence of pelvic floor hematoma was higher in vaginal-primiparous women than vaginal-multiparous women after vaginal delivery, hematomas were present in both groups. Future prospective studies are needed to evaluate the additive effect of multiple vaginal deliveries on the pelvic floor.

Change in prevalence of major levator ani muscle defects from 6 weeks to 1 year postpartum, and maternal and obstetric risk factors: A longitudinal ultrasound study

INTRODUCTION

The present study aimed first to investigate the change in prevalence of major levator ani muscle (LAM) defects, also called avulsions, from 6 weeks to 1 year postpartum, and second to assess maternal and obstetric risk factors for having persistent major LAM defects/avulsions at 1 year postpartum.

MATERIAL AND METHODS

This is a secondary analysis of data from a prospective cohort study including 300 nulliparous women at 17-19 weeks of gestation. Major LAM defects were diagnosed at 6 weeks and 1 year postpartum using transperineal ultrasonography. We defined persistent major LAM defects as a defect diagnosed both at 6 weeks and 1 year postpartum. Maternal and obstetric data were obtained from the hospital's electronic birth records. Pelvic floor muscle function was measured vaginally by manometer at 21 weeks of gestation. The main outcome measurement was change in prevalence of major LAM defects. Maternal and obstetric risk factors for having persistent major LAM defect were also assessed.

RESULTS

Prevalence of major LAM defects was 19.4% at 6 weeks and 10.4% at 1 year postpartum. No new major LAM defects were diagnosed at 1 year postpartum. Persisting major LAM defects were associated with longer second stage of labor (median 74.5 minutes vs median 48.0 minutes, P = .012) and higher neonatal birthweight (mean difference of 232.3 g, 95% confidence interval [CI] 21.5-443.1). Vacuum delivery was independently associated with persistent major LAM defects, adjusted OR 3.0 (95% CI 1.0-9.0).

CONCLUSIONS

There was a 50% reduction of sonographically diagnosed major LAM defects from 6 weeks to 1 year postpartum. This finding suggests that assessment of the major LAM 6 weeks postpartum may be too early to diagnose defects/avulsions. Long second stage of labor, high neonatal birthweight and vacuum delivery were associated with persistent major LAM defects/avulsions.

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.

Postnatal pelvic floor muscle stiffness measured by vaginal elastometry in women with obstetric anal sphincter injury: a pilot study

Introduction and hypothesis

Vaginal childbirth is associated with pelvic floor muscle (PFM) damage in a third of women. The biomechanics prediction, detection and management of PFM damage remain poorly understood. We sought in this pilot study to determine whether quantifying PFM stiffness postnatally by vaginal elastometry, in women attending a perineal trauma clinic (PTC) within 6 months of obstetric anal sphincter injury, correlates with their antecedent labour characteristics, pelvic floor muscle damage, or urinary/bowel/sexual symptoms, to inform future definitive prospective studies.

Methods

In this pilot study, we measured postnatal PFM stiffness by vaginal elastometry in 54 women. A subset of participants (n = 14) underwent magnetic resonance imaging (MRI) to define any levator ani (LA) muscle defects from vaginal childbirth. We investigated the association of PFM stiffness with demographics, labour and delivery characteristics, clinical features and MRI evidence of LA damage.

Results

Raised maternal BMI was associated with reduced pelvic floor stiffness (r = −0.4; p < 0.01). Higher stiffness values were associated with forceps delivery for delayed second stage of labour (n = 14) vs non-forceps vaginal delivery (n = 40; 630 ± 40 N/m vs 500 ± 30 N/m; p < 0.05), and a non-significant trend towards longer duration of the second stage of labour. Women with urinary, bowel or sexual symptoms (n = 37) demonstrated higher pelvic floor stiffness values than those without (570 ± 30 N/m vs 450 ± 40 N/m; p < 0.05).

Conclusions

A history of delayed second stage of labour and forceps delivery was associated with higher PFM stiffness values in the postnatal period. Whether high pelvic muscle stiffness antenatally is a risk factor for instrumental vaginal delivery and LA avulsion is unknown.

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.

Fundal pressure in second stage of labor (Kristeller maneuver) is associated with increased risk of levator ani muscle avulsion

OBJECTIVE

To investigate the association between application of fundal pressure during the second stage of labor (Kristeller maneuver) and the risk of levator ani muscle (LAM) injury.

METHODS

This was a prospective case-control study of women recruited immediately after their first vaginal delivery in our university hospital between March 2014 and September 2016. Women who underwent the Kristeller maneuver were recruited as cases. For each case, a control (no Kristeller) was recruited matched for body mass index, use of epidural analgesia, duration of second stage of labor and birth weight. All women were invited to undergo four-dimensional (4D) transperineal ultrasound (TPU) 3-6 months postpartum. The main outcome measure was the presence of LAM avulsion on 4D-TPU. TPU results were compared between cases and controls. Multivariate logistic regression analysis was performed to identify independent risk factors for LAM avulsion.

RESULTS

During the study period, 134 women in the Kristeller maneuver group and 128 women in the control group underwent TPU assessment. Women who underwent the Kristeller maneuver had a higher prevalence of LAM avulsion than did controls (38/134 (28.4%) vs 18/128 (14.1%); P = 0.005). In addition, women in the Kristeller-maneuver group had a larger hiatal area on maximum Valsalva maneuver and a greater increase in hiatal area from rest to maximum Valsalva. On multivariate logistic regression analysis, use of the Kristeller maneuver was the only independent factor associated with LAM avulsion (odds ratio, 2.5 (95% CI, 1.29-4.51)).

CONCLUSION

The Kristeller maneuver is associated with an increased risk of LAM avulsion when applied in women during their first vaginal delivery. This should be taken into account when deciding to use fundal pressure to accelerate the second stage of labor and when counseling women following childbirth. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Levator Avulsion Is Associated With Pelvic Organ Prolapse 23 Years After the First Childbirth

OBJECTIVES

This study aimed to ascertain the association between levator avulsion and pelvic organ prolapse (POP).

METHODS

This was a cross-sectional study involving 195 women enrolled in a longitudinal cohort study and seen 20 years after an index birth. All had a standardized patient-administered questionnaire, the International Continence Society Pelvic Organ Prolapse Quantification assessment and 4D translabial ultrasound. Main outcome measures were objective POP clinically and on translabial ultrasound. Postimaging assessment of levator integrity and sonographically determined pelvic organ descent was done blinded against other data.

RESULTS

Of 195 women who were seen a mean of 23 (range, 19.4-46.2) years after their first birth, one declined ultrasound assessment and was excluded, leaving 194. Mean age was 50.2 (range 36.9-66.5) years with a mean body mass index (BMI) of 27.6 (range, 18.3-54.3) kg/m² . Median parity was 3 (range 1-14). Ninety-one percent (n = 176) had delivered vaginally. Eighteen percent (n = 34) were symptomatic of prolapse. Clinically, 36% (n = 69) had significant POP. Levator avulsion was diagnosed in 16% (n = 31). Mean levator avulsion defect score was 2.2 (range, 0-12). On univariate analysis, levator avulsion and levator avulsion defect score were associated with clinically and sonographically significant POP, that is, odds ratio 2.6 (1.2-5.7), P = .01; and odds ratio 3.3 (1.4-7.7); P = .003, respectively; Ba (P < .001); bladder (P < .001); uterine (P < .001) and rectal ampulla (P = .009) descent, but not POP symptoms, C, and Bp. Multivariate analysis controlling for potential confounders confirmed our findings.

CONCLUSIONS

Levator avulsion is associated with female pelvic organ prolapse, especially of the anterior and central compartments. This association may become stronger with aging.

Atraumatic normal vaginal delivery: how many women get what they want?

BACKGROUND

Trauma to the perineum, levator ani complex, and anal sphincter is common during vaginal childbirth, but often clinically underdiagnosed, and many women are unaware of the potential for long-term damage.

OBJECTIVE

In this study we use transperineal ultrasound to identify how many women will achieve a normal vaginal delivery without substantial damage to the levator ani or anal sphincter muscles, and to create a model to predict patient characteristics associated with successful atraumatic normal vaginal delivery.

STUDY DESIGN

This is a retrospective, secondary analysis of data sets gathered in the context of an interventional perinatal imaging study. A total of 660 primiparas, carrying an uncomplicated singleton pregnancy, underwent an antepartum and postpartum interview, vaginal exam (Pelvic Organ Prolapse Quantification), and 4-dimensional translabial ultrasound. Ultrasound data were analyzed for levator trauma and/or overdistention and residual sphincter defects. Postprocessing analysis of ultrasound volumes was performed blinded against clinical data and analyzed against obstetric data retrieved from the local maternity database. Levator avulsion was diagnosed if the muscle insertion at the inferior pubic ramus at the plane of minimal hiatal dimensions and within 5 mm above this plane on tomographic ultrasound imaging was abnormal, ie the muscle was disconnected from the inferior pubic ramus. Hiatal overdistensibility (microtrauma) was diagnosed if there was a peripartum increase in hiatal area on Valsalva by >20% with the resultant area ≥25 cm². A sphincter defect was diagnosed if a gap of >30 degrees was seen in ≥4 of 6 tomographic ultrasound imaging slices bracketing the external anal sphincter. Two models were tested: a first model that defines severe pelvic floor trauma as either obstetric anal sphincter injury or levator avulsion, and a second, more conservative model, that also included microtrauma.

RESULTS

A total of 504/660 women (76%) returned for postpartum follow-up as described previously. In all, 21 patients were excluded due to inadequate data or intercurrent pregnancy, leaving 483 women for analysis. Model 1 defined nontraumatic vaginal delivery as excluding operative delivery, obstetric anal sphincter injuries, and sonographic evidence of levator avulsion or residual sphincter defect. Model 2 also excluded microtrauma. Of 483 women, 112 (23%) had a cesarean delivery, 103 (21%) had an operative vaginal delivery, and 17 (4%) had a third-/fourth-degree tear, leaving 251 women who could be said to have had a normal vaginal delivery. On ultrasound, in model 1, 27 women (6%) had an avulsion and 31 (6%) had a residual defect, leaving 193/483 (40%) who met the criteria for atraumatic normal vaginal delivery. In model 2, an additional 33 women (7%) had microtrauma, leaving only 160/483 (33%) women who met the criteria for atraumatic normal vaginal delivery. On multivariate analysis, younger age and earlier gestation at time of delivery remained highly significant as predictors of atraumatic normal vaginal delivery in both models, with increased hiatal area on Valsalva also significant in model 2 (all P ≤ .035).

CONCLUSION

The prevalence of significant pelvic floor trauma after vaginal child birth is much higher than generally assumed. Rates of obstetric anal sphincter injury are often underestimated and levator avulsion is not included as a consequence of vaginal birth in most obstetric text books. In this study less than half (33-40%) of primiparous women achieved an atraumatic normal vaginal delivery.

Recovery of puborectalis muscle after vaginal delivery: an ultrasound study

OBJECTIVES

To assess change in levator hiatal dimensions between pregnancy and different timepoints after vaginal delivery, and map recovery of the hiatus in order to contribute to secondary prevention of symptoms of pelvic floor disorders.

METHODS

Twenty nulliparous women with a singleton pregnancy underwent ultrasound assessment of the pelvic floor at rest, on maximum pelvic floor muscle contraction (PFMC) and on Valsalva maneuver at 12 weeks' gestation and at 1 day and 1, 2, 3, 4, 6, 12, 18 and 24 weeks after vaginal delivery. Dimensions of the levator hiatus were measured and contractility and distensibility were calculated. The Wilcoxon signed rank test was used to compare each postpartum value with that at 12 weeks' gestation.

RESULTS

Levator hiatal area at rest, on PFMC and on Valsalva maneuver was significantly increased at 1 day and at 1 and 2 weeks after vaginal delivery compared with measurements at 12 weeks' gestation. Hiatal area at rest and on PFMC from 3 weeks postpartum onward, as well as contractility from 6 weeks onward, were comparable to values at 12 weeks' gestation, whereas, a significant difference remained on Valsalva maneuver until 24 weeks after delivery. Moreover, distensibility was still increased at 24 weeks postpartum compared with measurements at 12 weeks' gestation.

CONCLUSION

The puborectalis muscle has the ability to recover anatomically from a first vaginal delivery, and recovery occurs mainly during the first 3 weeks after delivery. Stretching of the puborectalis muscle, as reflected by distensibility, persisted 24 weeks after the first vaginal delivery. The data provide a better understanding of the early 'normal' regeneration process and we hypothesize that the first 3 weeks postpartum is the best window in which to start secondary prevention. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Ultrasound in the assessment of pelvic organ prolapse

Imaging is increasingly being used in urogynaecology. Because of low cost and universal availability, ultrasound (US) is the most commonly used diagnostic modality, which allows the observation of manoeuvres such as Valsalva and pelvic floor muscle contraction in real time. The ability to see beyond surface anatomy is particularly important in the posterior compartment and in obstructed defecation where this method may replace defecation proctography. Imaging is especially useful in the form of 3D/4D multiplanar and tomographic translabial US, as these modalities give access to the axial plane and the levator ani. This allows assessment of both avulsion, i.e. major maternal birth trauma, and hiatal overdistension, i.e. ballooning. Both are major risk factors for both prolapse and prolapse recurrence. This review will outline current clinical utility, introduce recent research in the respective field and provide an overview of likely future utility of imaging in the investigation of pelvic organ prolapse.

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.

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.

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.

Determination of a cutoff value for pelvic floor distensibility using the Epi-no balloon to predict perineal integrity in vaginal delivery: ROC curve analysis. Prospective observational single cohort study

CONTEXT AND OBJECTIVE

Several risk factors are involved in perineal lacerations during vaginal delivery. However, little is known about the influence of perineal distensibility as a protective factor. The aim here was to determine a cutoff value for pelvic floor distensibility measured using the Epi-no balloon, which could be used as a predictive factor for perineal integrity in vaginal delivery.

DESIGN AND SETTING

Prospective observational single cohort study conducted in a maternity hospital.

METHODS

A convenience sample of 227 consecutive at-term parturients was used. All women had a single fetus in the vertex presentation, with up to 9.0 cm of dilation. The maximum dilation of the Epi-no balloon was measured using a tape measure after it had been inflated inside the vagina up to the parturients' maximum tolerance. The receiver operating characteristic (ROC) curve was used to obtain the Epi-no circumference measurement with best sensitivity and specificity.

RESULTS

Among the 161 patients who were included in the study, 50.9% underwent episiotomy, 21.8% presented lacerations and 27.3% retained an intact perineum. Age > 25.9 years; number of pregnancies > 3.4; number of deliveries > 2.2 and circumference measured by Epi-no > 21.4 cm were all directly correlated with an intact perineum. Circumference measurements using the Epi-no balloon that were greater than 20.8 cm showed sensitivity and specificity of 70.5% and 66.7% (area under curve = 0.713), respectively, as a predictive factor for an intact perineum in vaginal delivery.

CONCLUSION

Circumferences greater than 20.8 cm achieved using the Epi-no balloon are a predictive factor for perineal integrity in parturients.

Pelvic floor dysfunction, and effects of pregnancy and mode of delivery on pelvic floor

Pelvic floor dysfunction (PFD), although seems to be simple, is a complex process that develops secondary to multifactorial factors. The incidence of PFD is increasing with increasing life expectancy. PFD is a term that refers to a broad range of clinical scenarios, including lower urinary tract excretory and defecation disorders, such as urinary and anal incontinence, overactive bladder, and pelvic organ prolapse, as well as sexual disorders. It is a financial burden on the health care system and disrupts women's quality of life. Strategies applied to decrease PFD are focused on the course of pregnancy, mode and management of delivery, and pelvic exercise methods. Many studies in the literature define traumatic birth, usage of forceps, length of the second stage of delivery, and sphincter damage as modifiable risk factors for PFD. Maternal age, fetal position, and fetal head circumference are nonmodifiable risk factors. Although numerous studies show that vaginal delivery affects pelvic floor structures and their functions in a negative way, there is not enough scientific evidence to recommend elective cesarean delivery in order to prevent development of PFD. PFD is a heterogeneous pathological condition, and the effects of pregnancy, vaginal delivery, cesarean delivery, and possible risk factors of PFD may be different from each other. Observational studies have identified certain obstetrical exposures as risk factors for pelvic floor disorders. These factors often coexist; therefore, the isolated effects of these variables on the pelvic floor are difficult to study. The routine use of episiotomy for many years in order to prevent PFD is not recommended anymore; episiotomy should be used in selected cases, and the mediolateral procedures should be used if needed.

Pelvic floor ultrasound imaging: are physiotherapists interchangeable in the assessment of levator hiatal biometry?

PURPOSE

To evaluate inter-examiner reliability in the ultrasound (US) assessment of levator hiatal dimensions when different physiotherapists perform independent data acquisition and analysis.

METHODS

In this cross-sectional observational study, 14 asymptomatic nulliparous women were imaged at rest, during pelvic floor muscle contraction, and during Valsalva manoeuvre by two physiotherapists using three-dimensional (3D) and four-dimensional (4D) transperineal US. Examiners each measured the dimensions of the levator hiatus (area and antero-posterior and transverse diameters) from the US volumes they respectively acquired. Inter-examiner reliability was determined using intra-class correlation coefficients (ICCs), and inter-examiner agreement was determined using Bland-Altman analyses.

RESULTS

The ICC results demonstrated very good inter-examiner reliability (ICC=0.84-0.98); Bland-Altman results showed high inter-examiner agreement across all measurements.

CONCLUSIONS

Trained examiners may be considered interchangeable in the US assessment of levator hiatal biometry. Overall, trained physiotherapists using transperineal US imaging to assess levator hiatal biometry can be confident when comparing their own clinical findings to those of their colleagues and to findings published in the literature.

The levator ani muscle during pregnancy and major levator ani muscle defects diagnosed postpartum: a three- and four-dimensional transperineal ultrasound study

OBJECTIVE

To investigate associations between levator hiatus area and levator ani muscle function during pregnancy and major levator ani muscle defects postpartum.

DESIGN

Observational prospective cohort study.

SETTING

University hospital, Norway.

SAMPLE

A cohort of 234 nulliparous women at 21 and 37 weeks of gestation, and at 6 weeks postpartum.

METHODS

Ultrasound measurements of the levator hiatus at rest, during pelvic floor muscle contraction, and during the Valsalva manoeuvre were taken at 21 and 37 weeks of gestation. Levator ani muscle function was estimated as the percentage changes in levator ani muscle length from rest to contraction, and the level of muscle stretch during the Valsalva manoeuvre. Major levator ani muscle defects were diagnosed at 6 weeks postpartum using tomographic ultrasound imaging.

MAIN OUTCOME MEASURES

Associations between ultrasound measurements antepartum and major levator ani muscle defects postpartum.

RESULTS

Women with major levator ani muscle defects postpartum had significantly smaller levator hiatus area at rest and during the Valsalva manoeuvre at mid-pregnancy (mean difference 1.03 cm(2) , 95% CI 0.31-1.76; 2.92 cm(2) , 95% CI 1.77-4.07), and at 37 weeks of gestation (mean difference 1.47 cm(2) , 95% CI 0.62-2.32; 2.84 cm(2) , 95% CI 0.88-4.80), than women without such defects. They also had significantly less shortening of the levator ani muscle during contraction at 37 weeks of gestation.

CONCLUSIONS

Smaller levator hiatus area at rest and during the Valsalva manoeuvre at mid and late pregnancy, and less shortening of the levator ani muscle during contraction at 37 weeks of gestation, are associated with major levator ani muscle defects postpartum.

Assessing the impact of twin pregnancies on the pelvic floor using 3-dimensional sonography: a pilot study

OBJECTIVES

The purpose of this study was to compare the morphologic characteristics of the pelvic floor musculature between women with twin and singleton pregnancies.

METHODS

We conducted a cross-sectional case-control study of 40 nulliparous women aged 20 to 38 years to compare women with singleton pregnancies (n = 23) to women with twin pregnancies (n = 17). Biometric measurements of the levator hiatus and the sagittal and coronal diameters were made by transperineal 3-dimensional sonography between the 28th and 38th gestational weeks. Comparisons were statistically assessed by the unpaired Student t test and Mann-Whitney U test.

RESULTS

For the women with singleton pregnancies, the mean sagittal diameters at rest, during the Valsalva maneuver, and during pelvic floor contraction were 5.3, 5.7, and 4.5 cm, respectively, and the mean coronal diameters under these conditions were 3.8, 4.1, and 3.6 cm. For the women with twin pregnancies, the corresponding values were as follows: mean sagittal diameters, 5.3, 5.8, and 4.6 cm; and mean coronal diameters, 4.3, 4.3, and 3.8 cm. The differences in coronal diameters were statistically significant at rest (P < .01) and during contraction (P = .04). The mean levator hiatal areas for the women with singleton pregnancies were 14.6, 16.9, and 11.7 cm(2) at rest, during Valsalva, and during contraction, respectively; for the women with twin pregnancies, these values were 16.0, 18.6, and 12.6 cm(2).

CONCLUSIONS

Hiatal measurements were higher in twin than in singleton pregnancies, with coronal diameters reaching significance at rest and during contraction, suggesting that pelvic support undergoes greater changes during twin pregnancy.

The association between vaginal parity and hiatal dimensions: a retrospective observational study in a tertiary urogynaecological centre

OBJECTIVE

Vaginal childbirth has a substantial effect on pelvic organ supports, which may be mediated by levator ani (LA) avulsion or hiatal overdistension. Although the impact of a first vaginal delivery on the hiatus has been investigated, little is known about the effect of subsequent births. This study was designed to evaluate the association between vaginal parity and hiatal dimension.

DESIGN

Retrospective observational study.

SETTING

A tertiary urogynaecological unit in Australia.

POPULATION

A total of 780 archived data sets of women seen for symptoms of lower urinary tract and pelvic floor dysfunction.

METHODS

Standardised in-house interview and assessment using the International Continence Society (ICS) pelvic organ prolapse quantification (POP-Q), and four-dimensional translabial ultrasound. Offline analysis for hiatal dimensions was undertaken blinded to history and clinical examination.

MAIN OUTCOME MEASURES

Hiatal area on maximum Valsalva.

RESULTS

Of 780 women, 64 were excluded because of missing ultrasound volumes, leaving 716 for analysis: 96% (n = 686) were parous, with a median parity of three (interquartile range, IQR 2-3), and 91.2% (n = 653) were vaginally parous. Levator avulsion was found in 21% (n = 148). The mean hiatal area on Valsalva was 29 cm(2) (SD 9.4 cm(2) ). On one-way anova, vaginal parity was significantly associated with hiatal area (P < 0.001). Most of the effect seems to occur with the first delivery. Subsequent deliveries do not seem to have any significant effect on hiatal dimensions. This remained true after controlling for potential confounding factors using multivariate regression analysis (P = 0.0123).

CONCLUSIONS

Vaginal parity was strongly associated with hiatal area on Valsalva. Most of this effect seems to be associated with the first vaginal delivery.

Levator hematoma at the attachment zone as an early marker for levator ani muscle avulsion

OBJECTIVES

Childbirth causes overstretching of the levator ani muscle (LAM), predisposing to avulsion. LAM avulsion has not been evaluated early postpartum using endovaginal ultrasound (EVUS). The aim of this study was to evaluate the relationship between hematomas and LAM avulsion using EVUS and palpation early and late postpartum.

METHODS

Nulliparous women were studied prospectively at 36 weeks' gestation and within 4 days and 3 months postpartum. Palpation and high-frequency three-dimensional EVUS were performed. Two independent investigators reviewed the scans.

RESULTS

No antenatal LAM avulsions were found (n = 269). 114/199 (57.3%) women seen early postpartum agreed to examination. 27/114 (23.7%) had well delineated, hypoechoic areas consistent with hematomas (100% agreement), 26 following vaginal delivery, one following emergency Cesarean section. In total, 38 hematomas were found (11 bilateral, 16 unilateral). Hematomas away from the attachment zone of the LAM to the pubic bone (n = 22) resolved. Hematomas at the attachment zone (n = 16) manifested as pubococcygeus avulsions 3 months postpartum. In addition to these 16 avulsions, we found another 20 at 3 months postpartum. 13/20 were not scanned early postpartum and in seven no hematomas were seen, but avulsion was seen early postpartum. Overall, LAM avulsion was found in 23/191 (12.0%) women (13 bilateral, 10 unilateral) 3 months postpartum. Hematomas were significantly associated with episiotomy, instrumental delivery and increased hiatal measurements. Palpation was unreliable early postpartum as only seven avulsions were diagnosed.

CONCLUSION

Hematomas at the site of LAM attachment to the pubic bone always result in avulsion diagnosed 3 months postpartum. However, one third of avulsions are not preceded by a hematoma at the site of LAM attachment to the pubic bone.

How common is pelvic floor muscle atrophy after vaginal childbirth?

OBJECTIVE

To determine if there is evidence of levator ani atrophy in primiparous women.

METHODS

This was a prospective observational cohort study of 202 primiparous women recruited between November 2006 and March 2008. Translabial ultrasound volumes were obtained at 36-38 weeks' gestation and at a mean of 4.5 months postpartum. Peripartum changes in bladder neck elevation and reduction of anteroposterior hiatal diameter on pelvic floor muscle contraction (PFMC) and changes in muscle thickness were analyzed.

RESULTS

Of the 202 participants enrolled, 158 (78%) completed the study. There was a significant reduction in bladder neck elevation (P = 0.001) and change in anteroposterior hiatal diameter (P = 0.03) on PFMC when comparing antenatal and postnatal results, the latter being significantly associated with delivery mode (P = 0.013). No significant changes were detected in muscle thickness (P = 0.76).

CONCLUSIONS

There is a reduction in sonographic measures of pelvic floor function after childbirth, but muscle atrophy is unlikely to be a significant factor.

Pelvic floor biometry during a first singleton pregnancy and the relationship with symptoms of pelvic floor disorders: a prospective observational study

OBJECTIVE

To assess pelvic floor biometry during pregnancy and the correlation with symptoms of pelvic floor disorders in women.

DESIGN

A prospective observational study.

SETTING

Antenatal clinic between August 2009 and May 2011.

POPULATION

Nulliparous women in their first pregnancy.

METHODS

Pelvic floor was assessed by translabial ultrasound and symptoms of pelvic floor disorders were explored with a standardised questionnaire at each trimester.

MAIN OUTCOME MEASURES

Pelvic floor biometry during pregnancy.

RESULTS

A total of 405 (91.6%) women completed the study. As the pregnancy advanced, there was significant descent of the bladder neck (BN), cervix, and anorectal junction. The hiatal area (HA) was significantly enlarged, with a mean increase of 15.1 ± 24.8% at rest, and 24.7 ± 28.5% at Valsalva, at third trimester when compared with first trimester. Risk factors for stress urinary incontinence (SUI) were: descent of BN at Valsalva (OR 3.2, 95% CI 1.2-8.5), increase in HA at pelvic floor contraction (PFMC; OR 1.3, 95% CI 1.0-1.6), and increase in maternal age (OR 1.1, 95% CI 1.0-1.2), at first trimester; increase in HA at PFMC (OR 1.3, 95% CI 1.1-1.5) at second trimester; and descent of BN at rest (OR 2.3, 95% CI 1.1-4.9) and increase in maternal age (OR 1.1, 95% CI 1.02-1.2) at third trimester. Descent of anorectal junction (OR 1.5, 95% CI 1.1-1.9) and increase in HA at rest (OR 1.2, 95% CI 1.0-1.3) were factors for prolapse symptoms at second and third trimester, respectively.

CONCLUSIONS

Pelvic floor changes begin during pregnancy. There was significant descent of the BN, cervix, and anorectal junction, and enlargement of the hiatal area, as the pregnancy advanced. SUI was associated with descent of the BN, and prolapse symptoms were associated with an increase in the hiatal area.

Does levator trauma 'heal'?

OBJECTIVE

To evaluate if pregnancy- and delivery-related changes to levator morphology and distensibility regress with time.

METHODS

488 nulliparous pregnant women, recruited between 36 and 38 weeks' gestation, were invited for assessment at 3-6 months and again at 2-3 years postpartum. All underwent an interview and four-dimensional translabial ultrasound examination. Hiatal morphometry and bladder neck descent (BND) were determined and compared between the two postpartum visits.

RESULTS

367 participants returned for assessment at 4.1 (interquartile range (IQR), 3.7-5.0) months and 161 returned at 2.6 (IQR, 2.0-3.1) years, allowing a groupwise comparison. There was no significant difference in hiatal area (22 vs 22 cm(2), P = 0.95) or BND on Valsalva maneuver (26.3 vs 25.5 mm, P = 0.49). Pairwise comparison in women who had attended both postpartum appointments without second births (n = 77), separately for those who had a cesarean section (n = 24) and those who had a vaginal delivery (n = 53) originally, showed no significant changes, except a reduction in BND (31.2 vs 28.3 mm, P = 0.025) in those who had delivered vaginally. Two women out of 12 diagnosed with a levator avulsion at 3-6 months showed obvious anatomical improvement on translabial ultrasound at 2-3 years.

CONCLUSIONS

We found no evidence of regression or healing of pregnancy- and delivery-related changes to levator distensibility on comparing imaging data obtained at 3-6 months and 2-3 years postpartum. However, we documented anatomical improvement on translabial ultrasound at the second postpartum visit in two women diagnosed with levator avulsion at 3-6 months postpartum.

Obstetric levator ani muscle injuries: current status

Levator ani muscle (LAM) injuries occur in 13-36% of women who have a vaginal delivery. Although these injuries were first described using magnetic resonance imaging, three-dimensional transperineal and endovaginal ultrasound has emerged as a more readily available and economic alternative to identify LAM morphology. Injury to the LAM is attributed to vaginal delivery resulting in reduced pelvic floor muscle strength, enlargement of the vaginal hiatus and pelvic organ prolapse. There is inconclusive evidence to support an association between LAM injuries and stress urinary incontinence and there seems to be a trend towards the development of fecal incontinence. Longitudinal studies with long-term follow-up assessing the LAM before and after childbirth are lacking. Furthermore, the consequence of LAM injuries on quality of life due to prolapse and/or urinary and fecal incontinence have not been evaluated using validated questionnaires. Direct comparative studies using the above-mentioned imaging modalities are needed to determine the true gold standard for the diagnosis of LAM injuries. This would enable consistency in definition and classification of LAM injuries. Only then could high-risk groups be identified and preventive strategies implemented in obstetric practice.

Four-dimensional sonographic evaluation of avulsion of the levator ani according to delivery mode

OBJECTIVE

To determine the frequency of avulsion of the levator ani muscle in primiparous women according to delivery mode, using introital four-dimensional ultrasonography.

METHODS

We performed a prospective observational study at a tertiary obstetric unit. One hundred and eighty primiparous women were included and divided into three groups: normal vaginal delivery without episiotomy, forceps delivery and Cesarean section groups. Between 40 and 120 days after delivery, four-dimensional ultrasonography was performed in order to evaluate the integrity of the levator ani muscle. The operator was blinded to all clinical data and was not aware of delivery mode. The influence of other variables associated with delivery such as birth weight, body mass index, maternal age and use of epidural anesthesia was also studied.

RESULTS

Avulsion of the puborectalis component of the levator ani muscle was detected on ultrasonography in 61.7% of women who had undergone a forceps delivery, compared with 13.3% of those who had had a normal vaginal delivery and 0% of those who had had a Cesarean section. Bilateral avulsion was observed in 12/60 (20.0%) of the forceps group and in 2/60 (3.3%) of the normal vaginal delivery group (P < 0.001). Other variables did not seem to influence prevalence.

CONCLUSIONS

Forceps delivery is associated with an increased rate of avulsion of the puborectalis component of the levator ani muscle. The effect of forceps use is independent of other delivery-related variables.