Levator Ani Muscle Avulsion Research Articles

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

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. 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. 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. 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.

Parturition mode recommendation and symptoms of pelvic floor disorders after obstetric anal sphincter injuries.

Our primary objective was to evaluate parturition mode (PM) recommendations following obstetric anal sphincter injuries (OASIs) and adherence to these recommendations and to evaluate recurrence of OASIs in women who had a subsequent vaginal delivery (VD). The hypothesis was that adherence to the PM recommendations leads to a reasonable OASI recurrence rate. This was a retrospective observational cohort study of patients with previous OASIs between 2010 and 2016. After an outpatient visit including 3D transperineal ultrasound to screen for pelvic floor and anal sphincter injuries, all patients received recommendations for a subsequent PM. Patients were invited to complete validated questionnaires 2 to 5years post-OASIs. The majority of invited patients (265/320) attended follow-up, with 264 receiving a recommendation for PM. Only 5.6% did not adhere to the received recommendation. One hundred sixty-one patients delivered again, 58% had a VD, and 42% had a cesarean section (CS). Recurrence of OASIs was observed in 4.3% of the patients that had a VD. Fecal incontinence occurred in 4.9%, however any form of anal incontinence in 48% of patients. While dyspareunia was common in patients with residual external anal sphincter (EAS) injuries and levator ani muscle (LAM) avulsions, anal pain occurred more frequently in EAS injuries and fecal incontinence in LAM avulsions. This study showed that the vast majority of patients followed PM recommendations, and this resulted in a low recurrence of OASIs with a high CS rate. Fecal incontinence after OASIs was correlated with the degree of OASIs.

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

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. 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. 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). 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.

Prevalence of levator hiatal overdistension after vacuum and forceps deliveries.

Levator ani avulsion rates after assisted vaginal delivery have been reported in the literature. However, there are no definitive data regarding the association between overdistention and assisted vaginal delivery. Therefore, our aim is to report overdistention rates after assisted vaginal delivery with a postpartum ultrasound examination. This multicenter study involved a retrospective analysis of data from primiparous women (n = 602) who had previously been recruited at three tertiary hospitals between January 2015 and January 2017. Overdistention was assessed at 6 months postpartum using three-/four-dimensional transperineal ultrasound. Patients with levator ani muscle avulsion were excluded. Overdistention was defined as a levator hiatal area ≥ 25 cm2 on Valsalva. Of the 602 primiparous patients, 250 patients who satisfied the inclusion criteria (139 patients who underwent forceps delivery and 111 patients who underwent vacuum delivery) were evaluated. Overdistention occurred in 20% (50 of 250) of these patients. Overdistention was observed for 1% (1/111) of vacuum deliveries and 35.3% (49 of 139) of forceps deliveries. We found an increased risk of overdistention following forceps delivery compared to vacuum delivery, with a crude odds ratio (OR) of 59.9 (95% confidence interval [CI]: 8.1, 442.2) and an adjusted OR (adjusted for maternal age, second-stage duration, and head circumference) of 17.6 (95% CI: 2.3, 136.7). Postpartum overdistention occurred for 20% of assisted vaginal deliveries, with an increased risk of overdistention following forceps delivery compared to vacuum delivery.

Comparison between pelvic floor ultrasound and physical examination in the evaluation of cystocele

The main aim of this study was to explore the agreement between physical examination and ultrasound findings in the assessment of cystocele. It was a prospective observational study of women with primary cystocele. It enrolled 54 patients who underwent an interview, physical examination and 2D/3D transperineal ultrasound. The study included two observers: one who conducted the interview and carried out the examination, and another who performed the transperineal ultrasound. There was a concordance of 51.8% between examination and ultrasound concerning cystocele grading. In paravaginal defects, the concordance was 46.3%. In 42.6% of the patients, the ultrasound yielded better results for diagnosing paravaginal defect than the physical examination. Ultrasound revealed that levator ani muscle avulsion was present in 60.4% of patients and hiatal ballooning in 69.8%. In conclusion, the main utility of transperineal ultrasound is the evaluation of levator ani muscle integrity and urogenital hiatus through the axial plane in 3D.

Pelvic floor rehabilitation in patients with levator ani muscle avulsion

Pelvic floor rehabilitation in patients with levator ani muscle avulsion

The role of a new three-dimensional ultrasound technique in the diagnosis of levator ani muscle avulsion.

To evaluate the intermethod agreement between the tomographic ultrasound imaging (TUI), considered as the gold standard, and the OmniView-VCI in the diagnosis of levator ani muscle (LAM) avulsion and in the measurement of levator-urethral gap (LUG). We acquired dynamic 4D transperineal ultrasound volumes from 114 women. Each data set was analyzed on maximal pelvic floor contraction by TUI and OmniView-VCI techniques to check for LAM avulsion. Moreover, we measured LUG using both TUI and OmniView-VCI, twice by an operator and once by another to assess intraobserver and interobserver reproducibility. Reproducibility and intermethod agreement were studied by means of intraclass correlation coefficient (ICC) and Cohen's kappa coefficient. In the diagnosis of ani levator avulsion, the two techniques showed a good agreement (Cohen's κ = 0.691, 95% confidence interval [CI], 0.522-0.860; P < .001); we also reported a good intraobserver and interobserver agreement (Cohen's κ = 0.738, 95% CI, 0.597-0.879; P < .001, and Cohen's κ = 0.864, 95% CI, 0.750-0.978; P < .001, respectively). LUG measurements by OmniView-VCI technique showed high intraobserver (ICC 0.895; 95% CI, 0.866-0.918) and interobserver (ICC 0.821; 95% CI, 0.774-0.858) reproducibility. High intermethod agreement was demonstrated between the two methods (ICC 0.813; 95% CI, 0.764-0.853). The area under the receiver-operating characteristic curve of LUG in predicting avulsion was 0.931 (0.868-0.994, 95% CI; P < .001) with 24 mm showing the best sensitivity (82%) and specificity (97%). OmniView-VCI is a reliable method for LUG measurement and for levator avulsion diagnosis.

Are there differences in the damage to the pelvic floor between malmstrom's and kiwi omnicup vacuums? A multicenter study.

The objective of this study is to investigate a multicenter study to establish if differences exist in the levator ani muscle avulsion (LAM) rates between deliveries performed with Malmstrom's vacuum and the Kiwi vacuum. A prospective, multicenter observational study with 199 primiparous subjects was performed. All patients had undergone vaginal delivery by vacuum (Malmstrom's or Kiwi). Avulsion was defined as an abnormal insertion of LAM in the lower pubic branch in the multiplanar mode, as identified in the three central sections by transperineal 3/4D echography 6 months after delivery. The area of ​​the levator hiatus was measured in the plane of minimum dimensions at rest, during the Valsalva maneuver and during contraction. LAM avulsion occurred in 33.1% of cases in which Malmstrom's vacuum was used and in 29.4% of cases in which the Kiwi vacuum was used (the difference was not statistically significant), which resulted in a crude odds ratio (OR) of 0.977 (0.426, 2.241; P = .957) and an adjusted OR of 2.90 (0.691; 12.20; P = .146). Women in the Malmstrom's vacuum group had a larger LHA at rest 14.77 vs 12.64 cm2 ; P = .001) and at maximum contraction (13.41 vs 10.83 cm2 ; P < 0.001) in comparison with the Kiwi group, although the difference did not reach statistical significance under Valsalva maneuver (18.71 vs 17.21 cm2 ; P = .051).Differences between both groups were detected in the measurements of the hiatus area levator at rest (14.77 vs 12.64 cm2 ), during the Valsalva maneuver (18.71 vs 17.21 cm2 ) and during maximum contraction (13.41 vs 10.83 cm2 ). In the present study, Malmstrom's vacuum was not associated with a higher risk of LAM in comparison with Kiwi's Omnicup.

EP36.12: 4D ultrasound‐based triage to assess levator ani muscle avulsion in the surgical management of pelvic organ prolapse: preliminary results

EP36.12: 4D ultrasound‐based triage to assess levator ani muscle avulsion in the surgical management of pelvic organ prolapse: preliminary results

The effect of the first vaginal birth on pelvic floor anatomy and dysfunction

Introduction and hypothesisFirst vaginal delivery severely interferes with pelvic floor anatomy and function. This study determines maternal and pregnancy-related risk factors for pelvic floor dysfunction (PFD), including urinary incontinence (UI), urgency, anal incontinence (AI), pelvic organ prolapse (POP) and levator ani muscle (LAM) avulsion.MethodsThis is a single-centre prospective observational cohort study on healthy women in their first singleton pregnancy. All underwent clinical and 3D transperineal ultrasound examination at 6 weeks and 12 months postpartum. Objective outcomes were POP-Q and presence or absence of LAM trauma. Functional outcomes were measured by the ICIQ-SF and PISQ 12. Multivariate regression was performed to determine birth and maternal habitus-related risk factors for UI, urgency, AI, dyspareunia, LAM avulsion and ballooning.ResultsNine hundred eighty-seven women were included. Risk factors for UI were maternal age per year of age (OR: 1.09; 95% CI: 1.04–1.13; p = 0.0001) and BMI before pregnancy (OR: 1.08; 95% CI: 1.04–1.13; p = 0.001); for POP stage II+ maternal age (OR: 1.08; 95% CI: 1.08–1.14; p = 0.005). Avulsion was more likely after forceps (OR: 3.22; 95% CI:1.54–8.22; p = 0.015) but less likely after epidural analgesia (OR: 0.58; 95% CI: 0.37–0.90; p = 0.015) and grade I perineal rupture (OR: 0.50; 95% CI: 0.29–0.85; p = 0.012). Ballooning was more likely at increased maternal age (OR: 1.08; 95% CI: 1.02–1.13; p = 0.005), epidural (OR: 1.64; 95% CI: 1.06–2.55; p = 0.027) and grade I perineal rupture (OR: 1.79; 95% CI: 1.10–2.90; p = 0.018).ConclusionThough maternal characteristics at birth such as age or BMI increase the risk of PFD, labour and birth factors play a similarly important role. The most critical risk factor for MLA avulsion was forceps delivery, while an epidural had a protective effect.

Impact of levator muscle avulsions on Manchester procedure outcomes in pelvic organ prolapse surgery.

Levator ani muscle avulsions potentially increase recurrence after anterior colporrhaphies. We aimed at evaluating the impact of avulsions on anatomical and patient-reported outcomes 1year after the Manchester procedure for primary anterior compartment pelvic organ prolapse. Prospective cohort study of 189 women undergoing the Manchester procedure between October 2014 and January 2017. Avulsions were diagnosed by transperineal ultrasound. Women with and without avulsions were compared for 1-year postoperative outcomes; Pelvic Organ Prolapse Quantification measurements, subjective satisfaction (1-worse to 4-cured), failure (new prolapse treatment), response to validated questionnaires on pelvic floor distress and sexual function, and a composite outcome (subjectively cured and optimal anterior compartment outcome (stage 0-I)). Optimal mid-compartment outcome was defined as cervix≥5cm above the hymen. Factors potentially associated with poor anatomical outcomes (anterior compartment stage ≥II) or pelvic floor distress were analyzed using regression analyses. Fewer women with avulsions (present in 50.8%) obtained optimal mid-compartment outcomes (88.2% vs 77.1%; P=0.05). The groups were otherwise similar in terms of mid-compartment reduction, anterior compartment results, failure rate, subjective satisfaction, pelvic floor/sexual symptoms, and combined optimal subjective and anatomical outcome. Only preoperative anterior compartment stage ≥III was associated with poor anatomical outcome (P<0.01). A high preoperative symptom score was associated with a high postoperative symptom score (P<0.001). Although fewer women with avulsions obtained optimal mid-compartment results, avulsions had no impact on other anatomical or symptomatic outcomes 1year after the Manchester procedure for primary anterior compartment prolapse.

Pelvic organ prolapse as a function of levator ani avulsion, hiatus size, and strength

Obstetrical levator ani muscle avulsion is detected after 10%-30% of vaginal deliveries and is associated with pelvic organ prolapse later in life. However, the mechanism by which levator avulsion may contribute to prolapse is unknown. This study investigated the extent by which size of the levator hiatus and pelvic muscle weakness may explain the association between levator avulsion and pelvic organ prolapse. This was a supplementary study of a longitudinal cohort of parous women enrolled 5-10 years after first delivery and assessed annually for prolapse (defined as descent beyond the hymen) for up to 9 annual visits. For this substudy, vaginally parous participants were assessed for levator avulsion using 3-dimensional transperineal ultrasound. Ultrasound was performed at a median interval of 11 years from delivery. Ultrasound volumes also were used to measure levator hiatus area with Valsalva. Pelvic muscle strength was measured with perineometry. Women with and without pelvic organ prolapse were compared for levator avulsion, levator hiatus area, and pelvic muscle strength, using multivariable logistic regression yielding a measure of mediation. Bootstrap methods were used to calculate the confidence interval corresponding to the measure of mediation by hiatus area and pelvic muscle strength. Prolapse was identified in 109 of 429 (25%) and was significantly associated with levator avulsion (odds ratio, 4.17; 95% confidence interval, 2.28-7.31). Prolapse also was associated with levator hiatus area (odds ratio, 1.52 per 5 cm2; 95% confidence interval, 1.34-1.73) and inversely with muscle strength (odds ratio, 0.87 per 5 cm H2O; 95% confidence interval, 0.81-0.94). In a multivariable logistic model including levator avulsion, levator hiatus area, and strength, the association between levator avulsion and prolapse was substantially attenuated and indeed was no longer statistically significant (odds ratio, 1.75; 95% confidence interval, 0.91-3.39). Hiatus area and strength mediated 61% (95% confidence interval, 34%-106%) of the association between avulsion and prolapse. Furthermore, since the 95% confidence interval for this estimate contained 100%, it cannot be ruled out that the 2 markers fully mediate the effect of avulsion on prolapse. The strong association between pelvic organ prolapse and levator avulsion can be explained to a large extent by a larger levator hiatus and weaker pelvic muscles after levator avulsion.

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

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. 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 6months 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. 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. 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.

Delivery mode, levator avulsion and obstetric anal sphincter injury: A cross-sectional study 20years after childbirth.

Levator ani muscle (LAM) and anal sphincter injuries are common after vaginal birth and are associated with pelvic organ prolapse and anal incontinence. Our objective was to investigate long-term association between delivery mode, LAM avulsion and obstetric anal sphincter injuries (OASIS) in women at least 20years after their first birth. All women recruited at 'index birth' of the Dunedin (New Zealand) arm of ProLong (PROlapse and incontinence LONG-term research) Study, were invited to have translabial and transperineal ultrasound assessment of LAM and anal sphincters. Post-processing analysis of imaging data was performed blinded against delivery data. Statistical analysis was performed using the χ2 test and results are expressed as odds ratios (OR). Of the initial 1250 participants, 196 women returned for examination. Mean age was 50.8years with a mean body mass index of 27.6 and median parity was three. They were seen on average 23years after their first delivery. Four data sets were unavailable and one declined ultrasound assessment, leaving 191 for analysis. LAM avulsion was diagnosed in 29 (15.2%), and 24 women (12.6%) had significant anal sphincter defect. LAM avulsion was associated with forceps delivery (OR 2.45, 95% CI 1.04-5.80, P=0.041). Forceps conveyed a greater risk of OASIS (21%) compared to a spontaneous vaginal delivery (11%) but did not reach statistical significance. Forceps delivery is associated with long-term injurious effect on pelvic floor structures. Discussions of the long-term negative impact of pelvic floor structures and their functions are necessary to achieve an informed consent toward an operative vaginal delivery.

The impact of variations in obstetric practice on maternal birth trauma

Forceps delivery and length of second stage are risk factors of maternal birth trauma, i.e., levator ani muscle (LAM) avulsion and anal sphincter trauma. The cesarean section (CS) rate has recently become the key performance indicator because of its increase worldwide. Attempts to reduce CS rates seem to have led to an increase in forceps deliveries and longer second stages. This study aimed to determine the association between variations in obstetric practice (between hospitals) and maternal birth trauma. This was a retrospective ancillary analysis involving 660 nulliparous women carrying an uncomplicated singleton term pregnancy in a prospective perinatal intervention trial at two Australian tertiary obstetric units. They had been seen antenatally and at 3-6months postpartum for a standardized clinical assessment between 2007 and 2014. Primary outcome measures were sonographically diagnosed LAM and external anal sphincter (EAS) trauma. The incidence of LAM avulsion (11.5% vs. 21.3%, P = 0.01) and composite trauma, i.e., LAM avulsion ± EAS injury (29.2% vs. 39.7%, P = 0.03) were higher in one of the two hospitals, where the forceps delivery rate was also higher (10.9% vs. 2.6%, P < 0.001). BMI (OR 0.9, P = 0.02), length of second stage (OR 1.01, P = 0.02) and forceps delivery (OR 5.24, P < 0.001) were significant predictors of the difference in LAM avulsion incidence between the hospitals. Maternal age (OR 1.06, P < 0.04) and forceps delivery (OR 8.66, P < 0.001) were significant predictors for composite trauma. A higher incidence of LAM avulsion and composite trauma in one of the two hospitals was largely explained by a higher forceps delivery rate.

Birthweight and pelvic floor trauma after vaginal childbirth.

Birthweight seems to be a risk factor for levator ani muscle (LAM) avulsion and a predictive factor for pelvic organ prolapse (POP). Most trauma seems due to first vaginal birth. One thousand one hundred twenty-five women with at least two vaginal deliveries underwent a physician-directed interview, followed by clinical examination (digital palpation and Pelvic Organ Prolapse Quantification-POPQ) and 4D translabial ultrasound. Ultrasound volume data were obtained at rest, on pelvic floor contraction and Valsalva. The investigator, blinded to all other data, performed offline analysis of the LAM integrity and hiatal area on Valsalva. We tested for associations between birthweight of the first and of the largest vaginally born baby on the one hand and avulsion and symptoms/signs of prolapse on the other hand. Between July 2014 and July 2017, 1575 patients were seen. After exclusion of nulliparae and women with just one vaginal birth, 1202 remained. Another 77 were excluded due to missing data, leaving 1125. A significant association was found between birthweight and LAM avulsion as well as significant prolapse on POPQ. The birthweight of the first vaginally born baby was at least as predictive for avulsion as the birthweight of any subsequent births, even when adjusted for maternal age at first delivery and use of forceps. The birthweight of the first vaginally born baby is associated with levator avulsion and subsequent POP. Maximum weight of vaginal births does not seem to be a stronger predictor.

Pelvic Floor Disorders After Obstetric Avulsion of the Levator Ani Muscle.

With vaginal childbirth, 10% to 30% of women sustain levator ani muscle avulsion. The objective of this study was to estimate the cumulative incidence of prolapse and other pelvic floor disorders (PFDs), comparing vaginally parous women with and without levator avulsion. Parous women enrolled in a longitudinal study were assessed annually for PFDs with the Pelvic Organ Prolapse Quantification Examination (for prolapse) and the Epidemiology of Prolapse and Incontinence Questionnaire (for stress incontinence, overactive bladder, and anal incontinence). Three-dimensional transperineal ultrasound was used to identify levator avulsion. Women with and without levator avulsion after vaginal delivery were compared for the cumulative incidence of PFDs. Further analysis also stratified by forceps delivery. At the time of assessment, 453 participants were 6 to 17 years from first delivery (median, 11 years). Levator avulsion was identified in 15% (66/453) and was more common among those who had undergone forceps-assisted delivery (P < 0.001). Levator avulsion was strongly associated with prolapse beyond the hymen (odds ratio, 2.7; 95% confidence interval, 1.3-5.7) and with symptoms of prolapse (odds ratio, 3.0; 95% confidence interval-1.2, 7.3). These associations persisted after controlling for forceps-assisted delivery. In contrast, the odds of stress incontinence, overactive bladder, and anal incontinence were marginally (but not significantly) increased among women with levator avulsion in this cohort. Obstetric levator avulsion is strongly associated with pelvic organ prolapse. The relationship between levator avulsion and other PFDs may not be significant.

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

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. 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. 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)). 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.

Prediction Index of Levator Ani Muscle Avulsion After Vaginal Delivery: An Evidence-Based Appraisal

Pelvic floor dysfunction (PFD) due to vaginal delivery is related to tear of levator ani muscle (LAM) that potentially lead to the impairment of quality of life among women. A number of attempts to predict LAM injury after vaginal delivery had been conducted. This study aims to appraise the accuracy of several prediction index determining LAM injury after vaginal delivery. We conducted a search in Cochrane Library®, Pubmed®, and Medline® with the keywords of “pelvic floor dysfunction” AND “vaginal delivery” AND “prediction.” Critical appraisal determining the validity, importance, and applicability (VIA) was conducted by 2 independent authors. After 6 weeks to 3 months’ duration of follow up, the incidence of LAM avulsion was varied from 15.4% to 35.6% from three studies. Multivariate analysis showed that forceps delivery, OASIS, and active second stage (OR 3.8; 3.1; 1.61; respectively) as the most influential factors for LAM incidence. Maternal age and time spent in active pushing were also contributed to LAM incidence. OASIS and second stage of labor could be used as the most influential components of prediction index for LAM incidence. Prediction indexes for LAM incidence are developed. OASIS and second stage of labor are acknowledged as two most influential variables among three appraised studies.

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

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. 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. 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]). 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.