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

Prevalence of levator ani muscle injuries in primiparous women after delivery and their influence on pelvic floor disorders-systematic review

BACKGROUND

Studies show a significant association between the first vaginal delivery and injuries of the levator ani muscle (LAM), which can cause pelvic floor disorders (PFDs).

OBJECTIVES

This study aims to identify the prevalence of short and long-term LAM injuries after vaginal delivery in primiparous women and its influence on PFDs.

METHOD

A systematic review was conducted according to the PRISMA methodology. The databases used were Pubmed, Cochrane, and PEDro. The quality assessment of the evidence was carried out using the Critical Appraisal Skills Programme (CASP). Both the selection of studies and their evaluation were done by two researchers and a third reviewer in cases of disagreement.

RESULTS

From the search, 57 articles were gathered, and 19 were included to match the eligibility criteria. The prevalence of avulsion of the LAM was found in association with vaginal delivery between 13% and 28% ≤ 1 year after delivery and between 16% and 29% > 1 year after delivery. Ballooning was detected between 20% and 37% ≤ 1 year, and 33% of women > 1 year after delivery, appearing to be more common when compared to avulsion. Pelvic organ prolapse (POP) was considered the most common disorder associated with injuries of the LAM, and there seems to be some connection with sexual dysfunction.

CONCLUSION

Avulsion of the LAM and ballooning of the hiatal area have a high prevalence in primiparous women after vaginal delivery and have a strong direct relation to the development of POP.

Ultrasound examination of the pelvic floor during active labor: A longitudinal cohort study

INTRODUCTION

There is limited evidence about changes in the pelvic floor during active labor. We aimed to investigate changes in hiatal dimensions during the active first stage of labor and associations with fetal descent and head position.

MATERIAL AND METHODS

We conducted a longitudinal, prospective cohort study at the National University Hospital of Iceland, from 2016 to 2018. Nulliparous women with spontaneous onset of labor, a single fetus in cephalic presentation, and gestational age ≥37 weeks were eligible. Fetal position was assessed with transabdominal ultrasound and fetal descent was measured with transperineal ultrasound. Three-dimensional volumes were acquired from transperineal scanning at the start of the active phase of labor and in late first stage or early second stage. The largest transverse hiatal diameter was measured in the plane of minimal hiatal dimensions. The levator urethral gap was measured as the distance between the center of the urethra and the levator insertion using tomographic ultrasound imaging. Measurements of the levator urethral gap were made in the plane of minimal hiatal dimensions and 2.5 and 5 mm cranial to this.

RESULTS

The final study population comprised 78 women. The mean transverse hiatal diameter increased 12.4% between the two examinations, from 39.4 ± 4.1 mm (±standard deviation) at the first examination to 44.3 ± 5.8 mm at the last examination (p < 0.01). We found a moderate correlation between the transverse hiatal diameter and fetal station at the last examination (r = 0.44, r2  = 0.19; p < 0.01; regression equation y = 2.71 + 0.014x), and a weak correlation between the change in transverse hiatal diameter and change in fetal station (r = 0.29; r2  = 0.08; p = 0.01; regression equation y = 0.24 + 0.012x). Levator urethral gap increased significantly in all three planes on both the left and right sides. Head position was not associated with hiatal measurements after adjusting for fetal station.

CONCLUSIONS

We found a significant, but only modest, increase of the hiatal dimensions during the first stage of labor. The risk of levator ani trauma will therefore be low during this stage. The change in transverse hiatal diameter was associated with fetal descent but not with head position.

Vaginal delivery effects on 3D morphology of the bladder, urethra, and vagina: a pilot study comparing women with different numbers of deliveries

PURPOSE

To explore 3D morphological changes of the bladder, urethra, and vagina following different numbers of vaginal deliveries.

METHODS

Sampled patients had undergone magnetic resonance imaging for gynecological diseases in Nanfang Hospital. A total of 167 patients who met the study inclusion and exclusion criteria were enrolled and divided into four groups. Mimics and UG software packages were used for reconstructions and measurements, and data were compared with one-way analyses of variance.

RESULTS

A total of 167 3D models were constructed, and eight parameters related to the bladder and urethra were measured (5 angles, 2 lengths, and 1 thickness). No statistically significant differences were found between subgroups, although mean plot figures of urethra pubic and α angles showed trends to increase with more deliveries, and the opposite trend was seen for the urethra tilt angle. There were no obvious trends between other parameters and delivery number. There were seven vaginal parameters (6 lengths and 1 shape). Mid-urethral and vaginal gap measurements tended to become wider as delivery number increased, and the opposite was seen for the distal gap. Mid-vaginal 2D cross-sectional shape and the proportion of shallow concave types also tended to significantly increase with more deliveries, especially after the third birth.

CONCLUSION

As the number of deliveries through the vagina increases, the lateral support function of this organ and the urethra become relatively weaker. These fine anatomical changes are related to delivery numbers and become most obvious after the third birth.

Morphological Variation in the Pelvic Floor Muscle Complex of Nulliparous, Pregnant, and Parous Women

Specific levator ani muscle imaging measures change with pregnancy and vaginal parity, though entire pelvic floor muscle complex (PFMC) shape variation related to pregnancy-induced and postpartum remodeling has never been quantified. We used statistical shape modeling to compute the 3D variation in PFMC morphology of reproductive-aged nulliparous, late pregnant, and parous women. Pelvic magnetic resonance images were collected retrospectively and PFMCs were segmented. Modes of variation and principal component scores, generated via statistical shape modeling, defined significant morphological variation. Nulliparous (have never given birth), late pregnant (3rd trimester), and parous (have given birth and not currently pregnant) PFMCs were compared via MANCOVA. The overall PFMC shape, mode 2, and mode 3 significantly differed across patient groups (p < 0.001, = 0.002, = 0.001, respectively). This statistical shape analysis described greater perineal and external anal sphincter descent, increased iliococcygeus concavity, and a proportionally wider mid-posterior levator hiatus in late pregnant compared to nulliparous and parous women. The late pregnant group was the most divergent, highlighting differences that likely reduce the mechanical burden of vaginal childbirth. This robust quantification of PFMC shape provides insight to pregnancy and postpartum remodeling and allows for generation of representative non-patient-specific PFMCs that can be used in biomechanical simulations.

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.

Effects of Different Delivery Modes on Pelvic Floor Function in Parturients 6–8 Weeks after Delivery Using Transperineal Four-Dimensional Ultrasound

Objective

To evaluate the effects of different delivery modes on pelvic floor function in parturients 6–8 weeks after delivery using transperineal four-dimensional ultrasound.

Methods

Pelvic floor function 6–8 weeks after delivery in 40 vaginal delivery parturients between November 2018 and December 2020 was assessed by four-dimensional ultrasound, with 40 selective cesarean section delivery parturients as a control group. The imaging results of the two groups were compared.

Results

The levels of clinical indexes such as UVJ-M, A_r, A_v, θ, D_r, D_v, and ARJ-VDv in the selective cesarean section group were significantly lower than those in the vaginal delivery group 6–8 weeks after delivery (P < 0.05). However, no significant difference in CV-VD was observed under Valsalva action and at rest between the two groups (P > 0.05). No significant difference in ARJ-VD was found at rest between the two groups (P > 0.05). The incidence of pelvic organ prolapse in the selective cesarean section group (40.0%) was significantly lower than that in the vaginal delivery group (62.5%) (P < 0.05). No significant difference in the parameters of pelvic diaphragm hiatus at rest was observed between the two groups (P > 0.05). The parameters of pelvic diaphragm hiatus under maximum Valsalva action in the vaginal delivery group were significantly higher than those in the selective cesarean section group (P < 0.05). Whether the patient was complicated with diabetes had no significant effect on the functional injury of pelvic floor muscle (P > 0.05).

Conclusion

The pelvic floor function 6–8 weeks after delivery was significantly more affected in vaginal delivery than in selective cesarean section. Selective cesarean section had certain but limited protective effect on maternal pelvic floor tissue.

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.

Natural history of levator ani muscle avulsion 4 years following childbirth

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Postpartum perineal muscle sonogram in Madura beef cow

Background and Aim:

Ultrasonography (USG) is useful for non-invasively identifying changes that occur in soft tissue architecture. The objective of this research was to demonstrate postpartum (PP) uterine involution through the changes of perineal muscle intensity and thickness in Madura beef cow by ultrasonography.

Materials and Methods:

Madura’s breed cows used in the research consist of eight non-pregnant (NP) cows and three PP cow. The transrectal and transperineal USG imaging of NP cows was performed on days 1, 33, and 65. USG imaging of PP cows was performed every day starting from day 1 (24 h after parturition) until day 21 PP. Transrectal USG of the reproductive tract was performed for the cervix, corpus uteri, and cornua uteri. USG was performed transcutaneously over the perineal area for coccygeus and levator ani muscles at the longitudinal and transverse angles. Reproductive tract diameter and perineal muscle intensity and thickness were measured with ultrasound imaging.

Results:

The analysis of the sonogram of PP cows showed that the diameter of the cervix, corpus uteri, and cornua uteri decreased within 21 days PP. The transverse view of the coccygeus muscle of PP cows showed decreased muscle intensity and thickness. On the other hand, the longitudinal view showed increased coccygeus muscle intensity and thickness. The transverse view of the coccygeus muscle of NP cows showed increased muscle intensity, while muscle thickness was reduced. Sonogram analysis of the levator ani muscle of PP cows showed decreased muscle intensity with increasing muscle thickness. However, imaging of the levator ani muscle of NP cows showed a decrease in both intensity and muscle thickness. There was a significant difference in the mean value intensity of the scanning view analysis results of the levator ani muscle of the PP cow (523.6 AU increased to 672.1 AU) and the NP cow (515.9 AU decreased to 465.4 AU). Furthermore, there was a significant difference (p<0.05) in the mean value thickness of both scanning view analyses of the coccygeus and levator ani muscles of PP cows (5.8 mm increased to 6.5 mm and 3.8 mm increased to 4.8 mm, respectively) and NP cows (8.8 mm increased to 9.1 mm and 5.9 mm decreased to 4.9 mm, respectively).

Conclusion:

We found that the perineal muscles, namely, the levator ani muscle and coccygeus muscle, change in size, and intensity during uterine involution as demonstrated on Madura beef cow.

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 (β coefficient: estimative of effect in biometric progression according to GDM diagnosis, using the non-GDM group as reference = -6.76; P = .020), anteroposterior diameter (β = -5.07; P = .019), and Levator ani thickness (β = -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.

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.

New Method for Assessment of Levator Avulsion Injury: A Comparative Elastography Study

OBJECTIVE

The aim of this study was to introduce elastography as a new method for sonographic assessment of postpartum pelvic floor trauma.

METHODS

We examined 86 postpartum primiparous women, of whom 43 had undergone primary caesarean section (group_CS) and 43 vaginal delivery (group_VD). In a puborectal-symphysis plane, B-mode and elastographic ultrasonography were used to evaluate pelvic floor trauma. The strain value of left and right puborectal muscle was assessed close to the symphysis (Trauma_Elastography). The strain ratio maximum of this measurement was stored (Trauma_Index).

RESULTS

The elastographic evaluation revealed more trauma-suspicious lesions than the B-mode investigation (60.5% versus 39.5%; P < .001). The median Trauma_Index was higher in group_VD compared to group_CS (1.63 versus 1.18; P < .001).

CONCLUSION

Sonographic elastography assessment in a new examination plane shows postpartum trauma of the pelvic floor in women after vaginal delivery. This new method may help to identify women with a higher risk of postpartum pelvic floor disorders.

Recommended standardized terminology of the anterior female pelvis based on a structured medical literature review

BACKGROUND

The use of imprecise and inaccurate terms leads to confusion amongst anatomists and medical professionals.

OBJECTIVE

We sought to create recommended standardized terminology to describe anatomic structures of the anterior female pelvis based on a structured review of published literature and selected text books.

STUDY DESIGN

We searched MEDLINE from its inception until May 2, 2016, using 11 medical subject heading terms to identify studies reporting on anterior female pelvic anatomy; any study type published in English was accepted. Nine textbooks were also included. We screened 12,264 abstracts, identifying 200 eligible studies along with 13 textbook chapters from which we extracted all pertinent anatomic terms.

RESULTS

In all, 67 unique structures in the anterior female pelvis were identified. A total of 59 of these have been previously recognized with accepted terms in Terminologia Anatomica, the international standard on anatomical terminology. We also identified and propose the adoption of 4 anatomic regional terms (lateral vaginal wall, pelvic sidewall, pelvic bones, and anterior compartment), and 2 structural terms not included in Terminologia Anatomica (vaginal sulcus and levator hiatus). In addition, we identified 2 controversial terms (pubourethral ligament and Grafenberg spot) that require additional research and consensus from the greater medical and scientific community prior to adoption or rejection of these terms.

CONCLUSION

We propose standardized terminology that should be used when discussing anatomic structures in the anterior female pelvis to help improve communication among researchers, clinicians, and surgeons.

Does vaginal delivery cause more damage to the pelvic floor than cesarean section as determined by 3D ultrasound evaluation? A systematic review

INTRODUCTION AND HYPOTHESIS

Pregnancy and delivery are well-established risk factors for pelvic floor dysfunction (PFD), but the physiopathology, such as the delivery route, is not well understood. This study evaluated the impact of delivery route on the pelvic floor muscles via 3D ultrasound.

METHODS

This review is registered in the PROSPERO database. The criteria for inclusion were prospective studies with 3D translabial ultrasound assessment in primigravida women during pregnancy and postpartum published in English, Spanish or Portuguese between 1980 and 2016. We excluded studies that did not include the topic of urogenital hiatus measurement and literature reviews. The MeSH terms were obstetric delivery, postpartum period, labor, parturition, three-dimensional images, ultrasonography, pelvic floor, and pelvic floor disorders.

RESULTS

The search retrieved 155 articles. After analysis, 6 articles were included. Four studies showed that vaginal delivery (VD) was associated with a larger hiatal area. One study associated the hiatal area with levator ani muscle (LAM) defects in VD. Four articles evaluated the bladder neck, 3 of which showed a significant increase in bladder neck mobility associated with VD and 1 showed decreased bladder neck elevation, not associated with the delivery mode; the first 3 articles all evaluated LAM injuries and showed an association between VD and LAM injury. Women who underwent VD presented defects of the puborectalis muscle.

CONCLUSIONS

Vaginal delivery was associated with a higher number of LAM injuries, puborectalis defects, increased bladder neck mobility, and enlargement of the hiatal area.

The effect of water immersion delivery on the strength of pelvic floor muscle and pelvic floor disorders during postpartum period: An experimental study

BACKGROUND

Water immersion delivery is a non-pharmacological approach to ease labor pain. This paper aims to investigate the effect of water immersion delivery on increasing strength of pelvic floor muscle (PFM) and relieving pelvic floor disorders (PFDs) during postpartum period.

METHODS

A total of 2749 vaginal-delivery primiparas in postpartum 6-8 weeks were selected as research objects. Based on the modes of delivery, 600 patients were assigned into water immersion delivery group, 2149 were assigned into conventional delivery group. The scales of PFM strength and pelvic organ prolapsed (POP) were determined by specially trained personnel using digital palpation, and the symptoms of stress urinary incontinence (SUI) were investigated by questionnaire survey. The weak PFM strength was improved by doing Kegel exercise at home for 6-8 weeks.

RESULTS

We found that ①The rate of episiotomy in water immersion delivery group was 77.50% (465/600), which was lower than that in conventional delivery group (84.69%, 1820/2149) (P < .01); The primiparas without having an episiotomy have higher PFM strength than those having an episiotomy for both groups (P < .01). ②There was a negative correlation between the scale of PFM strength and SUI or POP, wherein the r-values were -0.135 and -0.435, respectively (P < .01). ③The rate of SUI was 6.50% (39/600) in water immersion delivery group and 6.89% (148/2149) in the conventional delivery group, wherein the intergroup difference was not significant (P > .05); ④The rates of vaginal wall prolapsed and uterus prolapsed were 29.83% (179/600) and 2.83% (17/600) in water immersion delivery group and 30.95% (665/2149) and 4.37% (94/2149) in the conventional delivery group, wherein the intergroup difference was not significant (P > .05). ⑤After Kegel exercise, the strength of PFM was promoted (P < .01).

CONCLUSION

Water immersion delivery has been proved to a beneficial alternative method for conventional delivery method. This delivery mode is associated with fewer episiotomy rate, and avoiding episiotomy is beneficial for maintaining PFM strength of women in postpartum 6-8 weeks. The strength of PFM during postpartum period can be improved by doing Kegel exercise at home.

Is curved three-dimensional ultrasound reconstruction needed to assess the warped pelvic floor plane?

OBJECTIVES

Caudal distension of the female pelvic floor is common and results in perineal descent and a caudally curved levator hiatus (warping). Image reconstruction of the pelvic floor using currently available ultrasound techniques involves a linear approach (flat-plane reconstruction). We aimed to evaluate the feasibility, reproducibility and potential usefulness of a new three-dimensional (3D) technique capable of reconstructing a curved plane of the levator hiatus.

METHODS

Primiparous women were recruited to undergo a 3D/four-dimensional transperineal ultrasound examination 3-6 months after delivery. Levator ani muscle warping was evaluated on Valsalva maneuver by measuring the distance between the plane extending from the pubic rami to the anorectal angle and the plane of minimal hiatal dimensions on the coronal plane. Warping distance was used to reconstruct a curved plane of the levator hiatus using the curved OmniView volume contrast imaging (VCI) technique (C-OV). Intra- and interobserver reproducibility of the C-OV technique were assessed, as was intermethod agreement between the C-OV technique and the linear OmniView-VCI (L-OV) technique, for the measurement of levator hiatal area on Valsalva maneuver.

RESULTS

Measurement of the levator hiatal area using C-OV was feasible in all 84 women recruited. The warping distance ranged from -3.5 to 9.7 mm, confirming that the 1-2-cm slice thickness traditionally used for linear reconstruction was adequate for proper assessment of levator hiatal area in our population. C-OV showed excellent intra- and interobserver reproducibility, as well as excellent agreement with the L-OV technique for measuring levator hiatal area. No systematic difference was demonstrated in any of the reproducibility studies performed.

CONCLUSIONS

3D reconstruction of the warped levator hiatal plane is feasible and highly reproducible. In our population, reconstruction of a curved plane to correct for levator hiatal warping did not offer any benefit over the traditionally performed linear reconstruction. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

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

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

Antenatal pelvic floor biometry is related to levator ani muscle injury

OBJECTIVE

To evaluate the relationship between antenatal pelvic floor biometry and levator ani muscle (LAM) injury in Chinese women.

METHODS

Three-dimensional transperineal ultrasound was performed in nulliparous Chinese women with a singleton pregnancy at 9-12 weeks, 26-28 weeks and 36-38 weeks of gestation and again at 12 months after delivery. Hiatal anteroposterior (AP) diameter, transverse diameter and area were measured on the antenatal ultrasound volumes obtained at rest, on Valsalva maneuver and during pelvic floor muscle contraction (PFMC). LAM injury was evaluated using ultrasound volumes obtained during PFMC at 12 months after delivery.

RESULTS

In total, 328 women completed the study. At 12 months after delivery, 38 (14.8% of those who delivered vaginally) women had LAM injury; 28 were unilateral (14 right- and 14 left-sided) and 10 were bilateral. In all three trimesters there was smaller hiatal AP diameter and hiatal area in women with LAM injury when compared with women without injury. On multivariable analysis of the three factors, hiatal AP diameter at rest, hiatal area at rest and operative vaginal delivery, only hiatal AP diameter at rest in all three trimesters was an independent factor of LAM injury. A larger hiatal AP diameter at rest in the first, second and third trimesters reduced the likelihood of LAM injury with odds ratios of 0.21, 0.15 and 0.21, respectively.

CONCLUSIONS

A smaller antenatal hiatal AP diameter at rest is a risk factor for LAM injury. The hiatal AP diameter is relatively simple to measure and the error in measurement is relatively small. A prospective study to confirm this relationship and to explore whether this measurement, performed in the midsagittal plane, is repeatable should be performed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.