Functional Anatomy of Urogenital Hiatus Closure: the Perineal Complex Triad Hypothesis.

INTRODUCTION: Urogenital hiatus enlargement is a critical factor associated with prolapse and operative failure. This study of the perineal complex was performed to understand how interactions among its three structures: the levator ani, perineal membrane, and perineal body-united by the vaginal fascia-work to maintain urogenital hiatus closure. METHODS: Magnetic resonance images from 30 healthy nulliparous women with 3D reconstruction of selected subjects were used to establish overall geometry. Connection points and lines of action were based on perineal dissection in 10 female cadavers (aged 22-86 years), cross sections of 4 female cadavers (aged 14-35 years), and histological sections (cadavers aged 16 and 21 years). RESULTS: The perineal membrane originates laterally from the ventral two thirds of the ischiopubic rami and attaches medially to the perineal body and vaginal wall. The levator ani attaches to the perineal membrane's cranial surface, vaginal fascia, and the perineal body. The levator line of action in 3D reconstruction is oriented so that the levator pulls the medial perineal membrane cranio-ventrally. In cadavers, simulated levator contraction and relaxation along this vector changes the length of the membrane and the antero-posterior diameter of the urogenital hiatus. Loss of the connection of the left and right perineal membranes through the perineal body results in diastasis of the levator and a widened hiatus, as well as a downward rotation of the perineal membrane. CONCLUSION: Interconnections involving the levator ani muscles, perineal membrane, perineal body, and vaginal fascia form the perineal complex surrounding the urogenital hiatus in an arrangement that maintains hiatal closure.

Relationship between pelvic floor muscle function and insulin resistance among non-diabetic females: a 3d ultrasound evaluation.

BACKGROUND: To use the three-dimensional (3D) ultrasound for assessment of pelvic floor muscle function in non-diabetic females with insulin resistance (IR), and to evaluate its functional relationship with insulin levels. METHODS: From October 2022 to November 2023, 216 non-diabetic females with insulin-resistant (IR group) and 118 normal females (control group) were sequentially recruited from our hospital for our study. The 3D ultrasound was used to assess the levator hiatus in resting state for all females regarding diameter lines, perimeters and areas; as well as the Valsalva manoeuvre (VM). The t-test and linear regression model were used to analyse the collected data. RESULTS: The analysis indicates that there were significant differences in the resting state of the levator hiatus between the IR and the control groups (14.8 ± 5.8 cm2 and 11.6 ± 2.7 cm2, p < 0.05); and in the VM (18.2 ± 6.3 cm2 and 13.4 ± 3. 4 cm2, p < 0.05). In addition, the anterior-posterior (AP) diameters of the hiatus on VM were significantly increased in the IR group (40.0 ± 4.7 mm and 33.0 ± 4.4 mm, p < 0.05). With insulin levels as the dependent variable, multivariate regression analysis shows that insulin levels were significantly correlated with the levator hiatus area on VM (p < 0.05) and waist circumference (p < 0.05). The pelvic organ descent on VM in the IR group was significant (p < 0.05). CONCLUSIONS: The areas of resting state levator hiatus and on VM were significantly larger in the IR than that in the control groups. In addition, the position of the pelvic organ on VM in the IR group was significantly descended. The insulin levels were correlated with the pelvic floor muscle function.

With regard to insulin resistance and pelvic floor function, previous studies focused on the role of polycystic ovaries, metabolic syndrome, and pelvic prolapse. The use of ultrasound can improve understanding of the static, dynamic and organ prolapse conditions. This study aimed to assess pelvic floor muscle function in non-diabetic women with insulin resistance, a condition where the body uses insulin less effectively. A total of 216 women with insulin resistance and 118 without it were examined using 3D ultrasound during rest and while performing the Valsalva manoeuvre. Our results show that the pelvic floor muscles had extra space between them and moved differently in women with insulin resistance than in those without the condition. This suggests that insulin resistance may affect function of pelvic floor muscles to cause adverse consequences.

A unified pelvic floor conceptual model for studying morphological changes with prolapse, age, and parity.

Several 2-dimensional and 3-dimensional measurements have been used to assess changes in pelvic floor structures and shape. These include assessment of urogenital and levator hiatus dimensions, levator injury grade, levator bowl volume, and levator plate shape. We argue that each assessment reflects underlying changes in an individual aspect of the overall changes in muscle and fascial structures. Vaginal delivery, aging, and interindividual variations in anatomy combine to affect pelvic floor structures and their connections in different ways. To date, there is no unifying conceptual model that permits the evaluation of how these many measures relate to one another or that reflects overall pelvic floor structure and function. Therefore, this study aimed to describe a unified pelvic floor conceptual model to better understand how the aforementioned changes to the pelvic floor structures and their biomechanical interactions affect pelvic organ support with vaginal birth, prolapse, and age. In this model, the pelvic floor is composed of 5 key anatomic structures: the (1) pubovisceral, (2) puborectal, and (3) iliococcygeal muscles with their superficial and inferior fascia; (4) the perineal membrane or body; and (5) the anal sphincter complex. Schematically, these structures are considered to originate from pelvic sidewall structures and meet medially at important connection points that include the anal sphincter complex, perineal body, and anococcygeal raphe. The pubovisceral muscle contributes primarily to urogenital hiatus closure, whereas the puborectal muscle is mainly related to levator hiatus closure, although each muscle contributes to the other. Dorsally and laterally, the iliococcygeal muscle forms a shelflike structure in women with normal support that spans the remaining area between these medial muscles and attachments to the pelvic sidewall. Other features include the levator plate, bowl volume, and anorectal angle. The pelvic floor conceptual model integrates existing observations and points out evident knowledge gaps in how parturition, injury, disease, and aging can contribute to changes associated with pelvic floor function caused by the detachment of one or more important connection points or pubovisceral muscle failure.

Validation of an automatic method for reconstruction, delineation, and measurement of levator hiatus in clinical practice.

OBJECTIVES: To evaluate the concordance between an automatic software program and manual evaluation in reconstructing, delineating, and measuring the levator hiatus (LH) on maximal Valsalva maneuver. METHODS: This was a retrospective study analyzing archived raw ultrasound imaging data of 100 patients underwent transperineal ultrasound (TPUS) examination. Each data were assessed by the automatic Smart Pelvic System software program and manual evaluation. The Dice similarity index (DSI), mean absolute distance (MAD), and Hausdorff distance (HDD) were calculated to quantify delineation accuracy of LH. Agreement between automatic and manual measurement of levator hiatus area was assessed by intraclass correlation coefficient (ICC) and Bland-Altman method. RESULTS: The satisfaction rate of automatic reconstruction was 94%. Six images were recognized as unsatisfactory reconstructed images for some gas in the rectum and anal canal. Compared with satisfactory reconstructed images, DSI of unsatisfactory reconstructed images was lower, MAD and HDD were larger (p = 0.001, p = 0.001, p = 0.006, respectively). The ICC was up to 0.987 in 94 satisfactory reconstructed images. CONCLUSIONS: The Smart Pelvic System software program had good performance in reconstruction, delineation, and measurement of LH on maximal Valsalva maneuver in clinical practice, despite misidentification of the border of posterior aspect of LH due to the influence of gas in the rectum.

Hiatal failure: effects of pregnancy, delivery, and pelvic floor disorders on level III factors.

INTRODUCTION AND HYPOTHESIS: The failure of the levator hiatus (LH) and urogenital hiatus (UGH) to remain closed is not only associated with pelvic floor disorders, but also contributes to recurrence after surgical repair. Pregnancy and vaginal birth are key events affecting this closure. An understanding of normal and failed hiatal closure is necessary to understand, manage, and prevent pelvic floor disorders. METHODS: This narrative review was conducted by applying the keywords "levator hiatus" OR "genital hiatus" OR "urogenital hiatus" in PubMed. Articles that reported hiatal size related to pelvic floor disorders and pregnancy were chosen. Weighted averages for hiatal size were calculated for each clinical situation. RESULTS: Women with prolapse have a 22% and 30% larger LH area measured by ultrasound at rest and during Valsalva than parous women with normal support. Women with persistently enlarged UGH have 2-3 times higher postoperative failure rates after surgery for prolapse. During pregnancy, the LH area at Valsalva increases by 29% from the first to the third trimester in preparation for childbirth. The enlarged postpartum hiatus recovers over time, but does not return to nulliparous size after vaginal birth. Levator muscle injury during vaginal birth, especially forceps-assisted, is associated with increases in hiatal size; however, it only explains a portion of hiatus variation-the rest can be explained by pelvic muscle function and possibly injury to other level III structures. CONCLUSIONS: Failed hiatal closure is strongly related to pelvic floor disorders. Vaginal birth and levator injury are primary factors affecting this important mechanism.

Postpartum pelvic floor muscle training, levator ani avulsion and levator hiatus area: a randomized trial.

INTRODUCTION AND HYPOTHESIS: Vaginal delivery may lead to tearing of the levator ani (LA) muscle from its bony insertions (complete LA avulsion) and increased levator hiatus (LH) area, both risk factors for pelvic floor dysfunctions. Early active rehabilitation is standard treatment after musculo-skeletal injury. We hypothesized that pelvic floor muscle training (PFMT) early postpartum would reduce the presence of LA avulsions and reduce LH area. METHODS: We carried out a planned secondary analysis from a randomized controlled study. Primiparous women (n=175) giving birth vaginally were included 6 weeks postpartum, stratified on complete LA avulsion, and thereafter randomized to PFMT or control. The training participants (n=87) attended a supervised PFMT class once a week and performed home-based PFMT daily for 16 weeks. The control participants (n=88) received no intervention. Presence of complete LA avulsion, LH area at rest, maximal contraction, and maximal Valsalva maneuver were assessed by transperineal ultrasound. Between-group comparisons were analyzed by analysis of covariance for continuous data, and relative risk (RR) for categorical data. RESULTS: Six months postpartum, the number of women who had complete LA avulsion was reduced from 27 to 14 within the PFMT group (44% reduction) and from 28 to 17 within the control group (39% reduction). The between-group difference was not significant, RR 0.85 (95% CI 0.53 to 1.37). Further, no significant between-group differences were found for LH area at rest, during contraction, or Valsalva. CONCLUSIONS: Supervised PFMT class combined with home exercise early postpartum did not reduce the presence of complete LA avulsion or LH area more than natural remission.

The Correlation Between the Sonographic Course of Transobturator Slings and Sling-Related Pain.

OBJECTIVES: To determine whether transobturator slings follow a consistent path and whether there is an association between ultrasonographically visualized sling pattern or position with sling-related pain. METHODS: This was a cross-sectional retrospective pilot study. We evaluated women who were presented to our clinic for pain or other urogynecologic symptoms following transobturator sling placement between 2009 and 2014. Patients had undergone a 3-dimensional endovaginal pelvic floor ultrasound, assessing minimal levator hiatus, antero-posterior diameter, left-right diameter, and the hiatal shape. The mesh patterns were categorized as seagull patterns (normal), lopsided, flat, and convoluted. RESULTS: A total of 68 cases were reviewed. Fifty patients reported pain, and 18 did not. There were wide variations in the course of the slings. The sling center- minimal levator hiatus position ranged 14.8 mm below and 17.9 mm above the minimal levator hiatus. The lateral arm insertion points ranged between 17.1 mm below and 16.6 mm above the minimal levator hiatus. The right arm insertion points ranged between 9.6 mm below and 18.8 mm above the minimal levator hiatus. Thirty-five of 68 (70%) patients with pain and 13 of 18 (72.2%) without had abnormal sling patterns. The abnormal sling shape was not correlated with pain (P = 1). The levator shape trended toward a statistical significant correlation with sling shape abnormality (P = .084). CONCLUSIONS: This population of women with transobturator sling complications demonstrated wide variations in anatomic paths. Neither the abnormal sling shape nor the distance of the center of the tape from the minimal levator hiatus level were correlated with pain.

Restoration of bladder neck activity and levator hiatus dimensions in Asian primipara: a prospective study.

Pelvic floor muscle training (PFMT) reduces the symptoms in women with pelvic floor dysfunction (PFD); however, the optimal initial timing for secondary prevention of PFD by PFMT is not clear. To identify the optimal timing in Asian primiparas with vaginal delivery, bladder neck descent (BND), levator hiatus areas, and levator hiatus distensibility and contractility were assessed in 26 nulliparous women at 36 weeks of gestation and at 2, 4, 6, and 12 weeks postpartum. We found that BND increased significantly from 2 weeks onwards until 6 weeks postpartum (p = 0.004); the levator hiatus area at rest and contraction both showed the largest value at 2 weeks postpartum (p = 0.005 and p < 0.005 respectively), followed by a continuous decrease; the hiatus area during Valsalva manoeuvre, and the levator hiatus distensibility and contractility showed the lowest value at 2 weeks postpartum, followed by a continuous increase; the changes in BND showed no correlation with the changes in distensibility or hiatus area during Valsalva manoeuvre (p = 0.073 and 0.590 respectively). In Asian primiparas with vaginal delivery, the recovery of levator hiatus and bladder neck mobility begins at 2 and 6 weeks, respectively. This information could be useful in defining the best time to begin PFMT for secondary prevention of postpartum PFD in Asian primiparous women.IMPACT STATEMENTWhat is already known on this subject? Pelvic floor muscle training (PFMT) helps to reduce symptoms of pelvic floor dysfunction (PFD), however, there are no clear time strategies for the secondary prevention of PFD by PFMT in Asian primiparas with vaginal delivery.What do the results of this study add? This study was the first longitudinal study in Asian primipara to investigate the natural regeneration of pelvic floor functions in the early postpartum period by intensively monitoring the bladder neck mobility and levator hiatus dimensions at multiple time points. We found that bladder neck descent (BND) increased significantly from 2 weeks onwards until 6 weeks postpartum; the levator hiatus area at rest and contraction both showed the largest value at 2 weeks postpartum, followed by a continuous decrease; the hiatus area during Valsalva manoeuvre, and the levator hiatus distensibility and contractility showed the lowest value at 2 weeks postpartum, followed by a continuous increase; the changes in BND showed no correlation with the changes in distensibility or hiatus area during Valsalva manoeuvre.What are the implications of these findings for clinical practice and/or further research? Our study suggested that in Asian primipara, the recovery of bladder neck mobility after vaginal delivery begins at 6 weeks postpartum, while the levator hiatus muscle begins to recover within the first 2 weeks postpartum. Therefore, it could be useful in deciding the best time to start PFMT for secondary prevention of postpartum PFD in Asian primiparous women.

Automatic identification and segmentation of slice of minimal hiatal dimensions in transperineal ultrasound volumes.

OBJECTIVE: To develop and validate a tool for automatic selection of the slice of minimal hiatal dimensions (SMHD) and segmentation of the urogenital hiatus (UH) in transperineal ultrasound (TPUS) volumes. METHODS: Manual selection of the SMHD and segmentation of the UH was performed in TPUS volumes of 116 women with symptomatic pelvic organ prolapse (POP). These data were used to train two deep-learning algorithms. The first algorithm was trained to provide an estimation of the position of the SMHD. Based on this estimation, a slice was selected and fed into the second algorithm, which performed automatic segmentation of the UH. From this segmentation, measurements of the UH area (UHA), anteroposterior diameter (APD) and coronal diameter (CD) were computed automatically. The mean absolute distance between manually and automatically selected SMHD, the overlap (dice similarity index (DSI)) between manual and automatic UH segmentation and the intraclass correlation coefficient (ICC) between manual and automatic UH measurements were assessed on a test set of 30 TPUS volumes. RESULTS: The mean absolute distance between manually and automatically selected SMHD was 0.20 cm. All DSI values between manual and automatic UH segmentations were above 0.85. The ICC values between manual and automatic UH measurements were 0.94 (95% CI, 0.87-0.97) for UHA, 0.92 (95% CI, 0.78-0.97) for APD and 0.82 (95% CI, 0.66-0.91) for CD, demonstrating excellent agreement. CONCLUSIONS: Our deep-learning algorithms allowed reliable automatic selection of the SMHD and UH segmentation in TPUS volumes of women with symptomatic POP. These algorithms can be implemented in the software of TPUS machines, thus reducing clinical analysis time and simplifying the examination of TPUS data for research and clinical purposes. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Impact of Laparoscopic Prolapse Repair in the Levator Hiatus Area.

STUDY OBJECTIVE: To determine whether laparoscopic surgery by sacrocolpopexy or sacrocervicopexy with posterior mesh attachment to levator ani to treat pelvic organ prolapse reduces the levator hiatus area, as measured by transperineal 3- and 4-dimensional ultrasound. The secondary objective was to assess the risk factors for prolapse recurrence. DESIGN: This is a prospective cohort study. SETTING: A university tertiary hospital. PATIENTS: Women with symptomatic apical prolapse at a high risk of recurrence were included. High risk of recurrence was defined as age <60 years and levator injury (avulsion and/or ballooning) or stage III-IV prolapse Pelvic Organ Prolapse Quantification. INTERVENTIONS: Women were treated with laparoscopic sacrocolpopexy or sacrocervicopexy. MEASUREMENTS AND MAIN RESULTS: Women underwent clinical examination according to assessment by the Pelvic Organ Prolapse Quantification system and transperineal ultrasound for the levator hiatus area at Valsalva. We collected demographic, clinical, and ultrasound data before surgery from clinical records and performed a comparative analysis of the levator hiatus areas before and after surgery and univariate and multivariate analyses of the risk factors for recurrence. Among the 30 women who enrolled, the levator hiatus area at Valsalva decreased significantly after surgery by an average of 4.68 cm2 (p = .028). However, despite a recurrence rate of 13.3%, we found no risk factors associated with recurrence in either the univariate or the multivariate analyses. CONCLUSION: Laparoscopic surgery by sacrocolpopexy or sacrocervicopexy for pelvic organ prolapse with mesh posterior attachment to levator ani significantly reduces the levator hiatus area measured by transperineal ultrasound. Further large-scale studies will be needed to confirm our results and identify risk factors for recurrence.

Longitudinal Study of Pelvic Floor Characteristics Before, During, and After Pregnancy in Nulliparous Women.

OBJECTIVES: To investigate the changes in the pelvic floor before, during, and after pregnancy in the same collective of nulliparous women. METHODS: In a prospective observational pilot study between April 2015 and June 2019 in nulliparous women with planned pregnancy, we used the pelvic organ prolapse quantification (POP-Q) system; a 2-dimensional (2D) sonography to investigate the bladder neck, cervix, and anorectal junction positions; and a 3D/4D sonography to measure the hiatus of the levator ani muscle (LH area) during Valsalva maneuver. Five visits were planned: 1 before, 3 during, and 1 visit after pregnancy. RESULTS: Twenty-four women participated in the study. We achieved a minimum of 2 visit measurements from 10 women who became pregnant. The LH area decreased during the first trimester and then increased until the third trimester. Postpartum, the LH area reached the prepregnancy state. We observed changes in the bladder neck mobility, bladder neck position, cervix, and anorectal junction from the first trimester. Postpartum, the bladder neck mobility was higher, and the position of the bladder neck and anorectal junction was lower than before pregnancy. We observed no remarkable changes in the POP-Q state during pregnancy. CONCLUSION: This was the first study to investigate pelvic floor characteristics in the same collective before, during, and after pregnancy. We observed pelvic floor changes from the prepregnancy state to the first trimester to postpartum. The study results need to be confirmed in a larger study.

Vaginal birth after Cesarean section and levator ani avulsion: a case-control study.

OBJECTIVE: The aim of this study was to explore the risk of levator ani muscle (LAM) avulsion and enlargement of the levator hiatus following vaginal birth after Cesarean section (VBAC) in comparison with vaginal delivery in primiparous women. METHODS: In this two-center observational case-control study, we identified all women who had a term VBAC for their second delivery at the Departments of Obstetrics and Gynecology at the Faculty of Medicine in Pilsen and the 1st Faculty of Medicine in Prague, Charles University, Czech Republic, between 2012 and 2016. Women with a repeat VBAC, preterm birth or stillbirth were excluded from the study. As a control group, we enrolled a cohort of primiparous women who delivered vaginally during the study period. To increase our control sample, we also invited all primiparous women who delivered vaginally in both participating units between May and June 2019 to participate. All participants were invited for a four-dimensional pelvic floor ultrasound scan to assess LAM trauma. LAM avulsion and the area of the levator hiatus were assessed offline from the stored pelvic floor volumes obtained at rest, during maximum contraction and during Valsalva maneuver. The laterality of the avulsion was also noted. The cohorts were then compared using the χ2 test and Wilcoxon's two-sample test according to the normality of the distribution. P < 0.05 was considered statistically significant. Multivariate regression analysis, controlling for age and body mass index (BMI), was also performed. RESULTS: A total of 356 women had a VBAC for their second delivery during the study period. Of these, 152 (42.7%) attended the ultrasound examination and full data were available for statistical analysis for 141 women. The control group comprised 113 primiparous women. A significant difference was observed between the VBAC group and the control group in age (32.7 vs 30.1 years; P < 0.05), BMI (28.4 vs 27.4 kg/m2 ; P < 0.05) and duration of the first and second stages of labor (293.1 vs 345.9 min; P < 0.05 and 27.6 vs 35.3 min; P < 0.05, respectively) at the time of the index birth. The LAM avulsion rate was significantly higher in the VBAC compared with the control group (32.6% vs 18.6%; P = 0.01). The difference between the groups was observed predominantly in the rate of unilateral avulsion and remained significant after controlling for age and BMI (adjusted odds ratio 2.061 (95% CI, 1.103-3.852)). There was no statistically significant difference in the area of the levator hiatus at rest (12.0 vs 12.6 cm2 ; P = 0.28) or on maximum Valsalva maneuver (18.6 vs 18.7 cm2 ; P = 0.55) between the VBAC and control groups. The incidence of levator hiatal ballooning was comparable between the groups (17.7% and 18.6%; P = 0.86). CONCLUSIONS: VBAC is associated with a significantly higher rate of LAM avulsion than is vaginal birth in nulliparous women. The difference was significant even after controlling for age and BMI. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Mechanisms of hiatus failure in prolapse: a multifaceted evaluation.

INTRODUCTION AND HYPOTHESIS: We investigated whether factors influencing pelvic floor hiatal closure are inter-related or independent, hypothesizing that (1) hiatus size is moderately correlated with levator defect, pelvic floor muscle strength, and change in hiatus size with contraction and (2) urogenital hiatus (UGH) and levator hiatus (LH) measures are similar in patients with anterior wall (AW) and posterior wall (PW) prolapse. METHODS: This cross-sectional case-control study included subjects with AW prolapse (n = 50), PW prolapse (n = 50), and normal support (n = 50). Hiatus measurements and levator defects were assessed on MRI, and vaginal closure force was measured with an instrumented speculum. Pearson correlation coefficients and simple and multivariable linear regression models were performed. RESULTS: During contraction, LH narrowed 47% more in the PW compared to AW group (p = 0.001). With straining, LH lengthened 34% more in the PW than AW group (p < 0.001). With straining, UGH and LH lengthening was greater by 72% and 44% in those with major compared to no/minor defect (p < 0.001 and p = 0.004). Contraction strength explained, at most, 4% of UGH (r = 0.17) or LH (r = 0.20) shortening during contraction (r = 0.17 and r = 0.20, respectively), indicating that these factors are largely independent. After controlling for prolapse size, resting UGH and levator defect status were associated with straining UGH (p < 0.001, p = 0.004), but muscle strength and resting tone were not. CONCLUSIONS: Hiatus measures are complex and differ according to prolapse occurrence and type. They are, at best, only weakly correlated with pelvic floor muscle strength and movement during contraction.

An ultrasound observation study on the levator hiatus with or without diastasis recti abdominis in postpartum women.

INTRODUCTION AND HYPOTHESIS: We hypothesized that differences in post-partum levator hiatus (LH) measurements, as well as the area of urethra and bladder (AUB), viewed under ultrasound, correlate with diastasis rectus abdominis (DRA) occurrence. The primary objective of this study is to determine ultrasound parameters available for diagnosing DRA in post-partum women. We compared LH and AUB measurements under ultrasound in primiparous women, with and without DRA, at 24-26 weeks postpartum. METHODS: One hundred ninety-four women underwent routine examination, including a self-made clinical symptoms questionnaire, DRA evaluation, and LH and AUB measurements. Independent samples t- and chi-squared tests were used to compare the differences between women with and without DRA. RESULTS: DRA incidence was significantly higher among those who underwent cesarean section (CS) than for vaginal delivery (VD) (P = 0.038). DRA patients could potentially have urinary urgency, frequency, pain, dysuria, and perineal tears. Additionally, statistically significant differences were found between VD patients, with or without DRA, in the resting LH transverse diameter (TrD) (P = 0.032) and the area of the levator hiatus (ALH) (P = 0.048) as well as AUB at Valsalva (P = 0.049). No differences, however, were found between the DRA and no DRA groups for all those measurements among women who had cesarean deliveries. CONCLUSIONS: DRA was more likely in post-CS women. Furthermore, the results showed a plausible association between DRA occurrence and LH expansion, especially in women with VD under rest and Valsalva. This could be useful for developing therapeutic plans based on these parameters for post-partum rehabilitation of women with DRA to avoid long-term complications.

Investigating the association of the dimensions of genital hiatus and levator hiatus with pelvic organ prolapse: a systematic review.

BACKGROUND AND HYPOTHESIS: Pelvic organ prolapse (POP) is a very common and distressing problem that affects women's quality of life. This systematic review aimed to investigate the association of the dimensions of the genital hiatus and levator hiatus at rest and Valsalva with POP. METHODS: The Cochrane Library, PubMed, Scopus, Embase and Web of Science were searched on 25 April 2020. All data were analyzed using Review Manager 5.3. RESULTS: Of the 1288 papers reviewed, 21 (n = 5145: 2909 women with POP and 2236 controls) were considered for meta-analysis. Compared with the normal pelvic floor group, the urogenital hiatus size in the POP group was significantly higher at rest (mean difference: 0.49; 95% CI: [0.43, 0.55], P < 0.00001) and at Valsalva (mean difference: 0.79; 95% CI: [0.70, 0.89], P < 0.00001). Also, the levator ani hiatus size in the POP group was significantly higher at rest (mean difference: 0.52, 95% CI: [0.25, 0.78], P < 0.0001) and at Valsalva (mean difference: 1.01; 95% CI: [0.73,1.28], P < 0.00001) compared with that in the normal pelvic floor group. CONCLUSION: This systematic review showed that the sizes of the urogenital hiatus and levator ani hiatus and area of the levator hiatus in the POP group were significantly higher than those in the normal pelvic floor groups in both positions (rest or Valsalva maneuver). Also, in the POP group, the levator hiatus length at rest was significantly lower than that in the Valsalva maneuver.

Does size matter? Perineometer and digital examination of a model levator hiatus.

INTRODUCTION: Evaluation of the female pelvic floor muscles is commonly carried out with digital examination and assigning a modified Oxford scale score or vaginal manometry. Racial differences can influence the size of the levator hiatus (LH) with "black" or African nulliparous women having a significantly larger LH compared to Caucasian women. The aim of this study was to assess the impact of LH size on manometry readings of simulated pelvic floor muscle contractions (PFMCs) using a small and large model LH. METHODS: Small and large LH models were created using published data for size. Inflation of a pressure cuff placed circumferentially in the LH model represented a simulated PFMC. The models were examined in a supine position by three examiners and a perineometer twice each at varying simulated PFMC strength. RESULTS: Positive correlation was found between increasing simulated PFMC strength with a higher Oxford score following digital examination and manometry readings for both the small (rs = .87, rs = .98) and large (rs = .95, rs = .87) models. There was good to excellent inter and intraobserver correlation for digital assessment of both models. The manometry measurements showed a much larger incremental rise from baseline in the small model compared with the large model (P < .05). CONCLUSION: This study demonstrates that perineometer readings are affected by natural variations in LH size and PFMC strength. Therefore improvement to pelvic floor strength cannot be interpreted and measurements cannot be compared with others unless the LH size is known or digital examination is carried out.

Impact of gestational diabetes on pelvic floor: A prospective cohort study with three-dimensional ultrasound during two-time points in pregnancy.

AIM: To evaluate the pelvic floor (PF) biometry using three-dimensional ultrasound (US) at two-time points of gestational in pregnant women with gestational diabetes mellitus (GDM). METHODS: A prospective cohort study conducted at the Perinatal Diabetes Research Center including 44 pregnant women with GDM and 66 pregnant women without GDM at 24 to 28 weeks of gestation. Three-dimensional transperineal US was performed at 24 to 28 and 34 to 38 weeks of gestation in the lithotomy position at rest. The axial plane of the minimal Levator hiatal dimensions was used to determine Levator ani muscle and Hiatal area (HA) biometry at 24 to 28 and 34 to 38 weeks of gestation. RESULTS: Of the 110 pregnant women, 100 (90.9%) completed the follow-up at 34 to 38 weeks of gestation. The evaluation by US showed a negative biometric change between the two-time points, during pregnancy in women with GDM; in the HA (ß coefficient: estimative of effect in biometric progression according to GDM diagnosis, using the non-GDM group as reference = -6.76; P = .020), anteroposterior diameter (ß = -5.07; P = .019), and Levator ani thickness (ß = -12.34; P = .005). CONCLUSIONS: Pregnant women with GDM had a significantly lower than expected percentage of changes in biometry of Levator ani thickness and HA from 24 to 28 to 34 to 38 weeks of gestation when compared with the group of pregnant women without GDM. GDM alters the morphology of PF structures assessed by three-dimension US. This reported complication may be implicated in adverse birth outcomes and may play a role in the development of PF dysfunction.

Contraction of the levator ani muscle during Valsalva maneuver (coactivation) is associated with a longer active second stage of labor in nulliparous women undergoing induction of labor.

BACKGROUND: The Valsalva maneuver is normally accompanied by relaxation of the levator ani muscle, which stretches around the presenting part, but in some women the maneuver is accompanied by levator ani muscle contraction, which is referred to as levator ani muscle coactivation. The effect of such coactivation on labor outcome in women undergoing induction of labor has not been previously assessed. OBJECTIVE: The aim of the study was to assess the effect of levator ani muscle coactivation on labor outcome, in particular on the duration of the second and active second stage of labor, in nulliparous women undergoing induction of labor. STUDY DESIGN: Transperineal ultrasound was used to measure the anteroposterior diameter of the levator hiatus, both at rest and at maximum Valsalva maneuver, in a group of nulliparous women undergoing induction of labor in 2 tertiary-level university hospitals. The correlation between anteroposterior diameter of the levator hiatus values and levator ani muscle coactivation with the mode of delivery and various labor durations was assessed. RESULTS: In total, 138 women were included in the analysis. Larger anteroposterior diameter of the levator hiatus at Valsalva was associated with a shorter second stage (r = -0.230, P = .021) and active second stage (r = -0.338, P = .001) of labor. Women with levator ani muscle coactivation had a significantly longer active second stage duration (60 ± 56 vs 28 ± 16 minutes, P < .001). Cox regression analysis, adjusted for maternal age and epidural analgesia, demonstrated an independent significant correlation between levator ani muscle coactivation and a longer active second stage of labor (hazard ratio, 2.085; 95% confidence interval, 1.158-3.752; P = .014). There was no significant difference between women who underwent operative delivery (n = 46) when compared with the spontaneous vaginal delivery group (n = 92) as regards anteroposterior diameter of the levator hiatus at rest and at Valsalva maneuver, nor in the prevalence of levator ani muscle coactivation (10/46 vs 15/92; P = .49). CONCLUSION: Levator ani coactivation is associated with a longer active second stage of labor.

Ultrasongraphic age-related changes of the pelvic floor muscles in nulliparous women and their association with pelvic floor symptoms: A pilot study.

OBJECTIVE: To assess age-related changes in the pelvic floor muscular hiatus and their association with symptoms of pelvic organ prolapse, urinary and fecal incontinence, and sexual function. METHODS: In this pilot study we performed 3D endovaginal ultrasonography in two age groups of nulliparous women: 18 to 40 years and 52 to 85 years. Anterior-posterior (AP) diameter, left-right (LR) diameter, and the Minimal Levator Hiatus area were measured. The AP/LR ratio was calculated to compare the shape of the pelvic floor muscles between participants (oval vs circular). Other measurements included length of the urethra, and levator plate lift. Participants were assessed for (1) distress symptoms of pelvic floor prolapse, urinary, and fecal symptoms by the Pelvic Floor Distress Inventory-20, (2) quality of life via the pelvic floor impact inventory-7, and (3) sexual function by the female sexual function inventory (FSFI-19). RESULTS: A total of 12 women into the younger group and 10 to the older group were recruited. Older women had higher AP/LR ratio and longer distance levator plate lift while performing the squeeze maneuver ( P = 0.017 and 0.038, respectively). Older women had worse urinary and pelvic organ prolapse symptoms ( P = 0.002 and 0.004, respectively). Fewer women in the older group were sexually active (60% vs 92%) and their quality of sexual life was lower based on their FSFI-19 results. CONCLUSION: Levator ani muscle hiatus changes to a more oval form in older nulliparous postmenopausal women and this change in shape is associated with increased pelvic floor symptoms.

Levator bowl volume during straining and its relationship to other levator measures.

INTRODUCTION AND HYPOTHESIS: This study was aimed at measuring levator ani bowl volume at rest and while straining, comparing women with and without prolapse (controls), and assessing the ability of measures of the mid-sagittal bowl area, levator hiatus (LH), and urogenital hiatus (UGH) to predict bowl volume. METHODS: Forty MRI scans previously acquired in case-control prolapse studies, including 20 women with prolapse and 20 women without prolapse, of similar age and parity, were selected. 3D models of rest and strain bowl volumes were made using sagittal scans and 3D Slicer®. Mid-sagittal bowl area, UGH, and LH were measured using ImageJ. Data were analyzed using two sample t tests, effect sizes, and Pearson's correlation coefficients at the 0.05 significance level. RESULTS: Data were acquired in a total of 40 total women. Levator bowl volume at strain had a correlation coefficient of 0.5 with bowl volume at rest. During straining, prolapse subjects had a 53% larger bowl volume than control subjects (254 ± 86 cm3 vs 166 ± 44 cm3, p < 0.001), but at rest, the difference was 34% (138 ± 40 cm3 vs 103 ± 25 cm3, p = 0.002). Effect sizes for all parameters were large (d > 0.75). The strongest correlation with straining bowl volume was mid-sagittal straining bowl area (r = 0.86), followed by LH strain (r = 0.80), then UGH strain (r = 0.76). CONCLUSIONS: Straining levator bowl volume is substantially different than measures made at rest, with only a quarter of straining values explained by resting measurements. The bowl area at strain is the best 2D measurement estimating bowl volume and explains 74% of straining bowl volume.