Role of fibulin-5 insufficiency and prolapse progression on murine vaginal biomechanical function.

The vagina plays a critical role in supporting the pelvic organs and loss of support leads to pelvic organ prolapse. It is unknown what microstructural changes influence prolapse progression nor how decreased elastic fibers contributes to vaginal remodeling and smooth muscle contractility. The objective for this study was to evaluate the effect of fibulin-5 haploinsufficiency, and deficiency with progressive prolapse on the biaxial contractile and biomechanical function of the murine vagina. Vaginas from wildtype (n = 13), haploinsufficient (n = 13), and deficient mice with grade 1 (n = 9) and grade 2 or 3 (n = 9) prolapse were explanted for biaxial contractile and biomechanical testing. Multiaxial histology (n = 3/group) evaluated elastic and collagen fiber microstructure. Western blotting quantified protein expression (n = 6/group). A one-way ANOVA or Kruskal-Wallis test evaluated statistical significance. Pearson's or Spearman's test determined correlations with prolapse grade. Axial contractility decreased with fibulin-5 deficiency and POP (p < 0.001), negatively correlated with prolapse grade (ρ = - 0.80; p < 0.001), and positively correlated with muscularis elastin area fraction (ρ = - 0.78; p = 0.004). Circumferential (ρ = 0.71; p < 0.001) and axial (ρ = 0.69; p < 0.001) vaginal wall stresses positively correlated with prolapse grade. These findings demonstrated that fibulin-5 deficiency and prolapse progression decreased vaginal contractility and increased vaginal wall stress. Future work is needed to better understand the processes that contribute to prolapse progression in order to guide diagnostic, preventative, and treatment strategies.

Investigation of Murine Vaginal Creep Response to Altered Mechanical Loads.

The vagina is a viscoelastic fibromuscular organ that provides support to the pelvic organs. The viscoelastic properties of the vagina are understudied but may be critical for pelvic stability. Most studies evaluate vaginal viscoelasticity under a single uniaxial load; however, the vagina is subjected to dynamic multiaxial loading in the body. It is unknown how varied multiaxial loading conditions affect vaginal viscoelastic behavior and which microstructural processes dictate the viscoelastic response. Therefore, the objective was to develop methods using extension-inflation protocols to quantify vaginal viscoelastic creep under various circumferential and axial loads. Then, the protocol was applied to quantify vaginal creep and collagen microstructure in the fibulin-5 wildtype and haploinsufficient vaginas. To evaluate pressure-dependent creep, the fibulin-5 wildtype and haploinsufficient vaginas (n = 7/genotype) were subjected to various constant pressures at the physiologic length for 100 s. For axial length-dependent creep, the vaginas (n = 7/genotype) were extended to various fixed axial lengths then subjected to the mean in vivo pressure for 100 s. Second-harmonic generation imaging was performed to quantify collagen fiber organization and undulation (n = 3/genotype). Increased pressure significantly increased creep strain in the wildtype, but not the haploinsufficient vagina. The axial length did not significantly affect the creep rate or strain in both genotypes. Collagen undulation varied through the depth of the subepithelium but not between genotypes. These findings suggest that the creep response to loading may vary with biological processes and pathologies, therefore, evaluating vaginal creep under various circumferential loads may be important to understand vaginal function.

Microscopic Hematuria as a Screening Tool for Urologic Malignancies in Women.

INTRODUCTION: Most causes of microscopic hematuria (MH) are benign but may indicate an underlying malignancy. Current MH evaluation guidelines are reflective of male urologic malignancy risks. The objective of this systematic review was to evaluate whether the finding of MH predicts subsequent urologic malignancy in women. METHODS: MEDLINE was searched between January 1990 and June 8, 2018. The positive predictive value (PPV) of MH as a screening tool for urologic malignancy was calculated for each study individually and collectively. The pooled relative risk of urologic malignancy associated with MH was calculated. RESULTS: Seventeen studies were included. Eight studies included only women. In total, 300 urinary tract cancers were identified in 110,179 women with MH. The PPV of MH as a screening tool for cancer ranged from approximately 0.6% to 2.8%; confidence intervals (CIs) suggested this is a relatively unstable performance indicator because of small sample sizes. Average PPV across all studies was 2.13%, but the weighted average PPV was 0.24%. The risk of urologic malignancies among women with relative those without MH was 2.01 (95% CI, 1.61-2.51). Based on these limited data, we estimate that 859 (95% CI, 654-1250) women with MH would require complete evaluation to identify 1 urinary tract malignancy. CONCLUSIONS: A very small proportion of women with MH are likely to have a urologic malignancy. Approximately 859 women require full screening to identify 1 malignancy. Current evidence is limited, and further studies, specifically in women, are needed.

Cutaneous Myiasis in Rural Haiti.

Background: Myiasis is a disease caused by the infestation of human tissue by the larval stage of various flies. It has been identified in sub-Saharan Africa and in tropical parts of the Americas. Cases have also been identified among travelers returning to the United States. Infestations may involve any part of the body, including the scalp, and open wounds may become infected with these larvae. The primary cause of wound myiasis in the western hemisphere is Cochliomyia hominivorax. Case Report: We present a case of wound myiasis in an adult Haitian male with a persistent wound for 2 years. To our knowledge, only 1 other report of wound myiasis in Haiti caused by C hominivorax has been published. Conclusion: Wound myiasis can occur in many tropical regions of the world, including Haiti. Because of the prevalence of global travel, clinicians should be familiar with the condition's diagnosis and management.

Comparison of Biaxial Biomechanical Properties of Post-menopausal Human Prolapsed and Non-prolapsed Uterosacral Ligament.

Uterosacral ligaments (USLs) provide structural support to the female pelvic floor, and a loss of USL structural integrity or biomechanical function may induce pelvic organ prolapse (POP). Alterations in extracellular matrix composition and organization dictate USL mechanical function. Changes in USL microstructure and corresponding mechanical properties, however, are not fully understood, nor is it understood how microstructure and mechanics change with onset and progression of POP. This is due, in part, as USL properties are primarily characterized along a single direction (uniaxial test), whereas the USL is loaded in multiple directions simultaneously within the body. Biaxial testing permits the acquisition of biomechanical data from two axes simultaneously, and thus simulates a more physiologic assessment compared to the traditional uniaxial testing. Therefore, the objective of this study was to quantify the biaxial biomechanical properties and histological composition of the USL in post-menopausal women with and without POP at various stages. Potential correlations between tissue microstructural composition and mechanical function were also examined. Tangential modulus was lower and peak stretch higher in POP III/IV compared to non-POP and POP I/II in the main in vivo loading direction; however, no significant differences in mechanical properties were observed in the perpendicular loading direction. Collagen content positively correlated to tangential modulus in the main in vivo loading direction (r = 0.5, p = 0.02) and negatively correlated with the peak stretch in both the main in vivo (r = -0.5, p = 0.02) and perpendicular loading directions (r = -0.3, p = 0.05). However, no statistically significant differences in USL composition were observed, which may be due to the small sample size and high variability of small sections of human tissues. These results provide first step towards understanding what microstructural and mechanical changes may occur in the USL with POP onset and progression. Such information may provide important future insights into the development of new surgical reconstruction techniques and graft materials for POP treatment.

Botulinum Toxin A: A Review of Potential Uses in Treatment of Female Urogenital and Pelvic Floor Disorders.

Background: Botulinum toxin is an injectable neuromodulator that inhibits transmission between peripheral nerve endings and muscle fibers, resulting in muscle paralysis. Botulinum toxin type A is the most common form of botulinum toxin used in clinical practice. Methods: In this review, we examine the mechanism of action, formulations, common clinical use in the genital-urinary tract, and potential clinical use in pelvic floor disorders of botulinum toxin type A. Results: Several aspects of botulinum toxin A make it a favorable therapeutic tool, including its accessibility, its longevity, and its impermanence and reversibility of resultant chemodenervation in a relatively short and safe manner. Although botulinum toxin A has well-established efficacy in treating refractory overactive bladder and neurogenic detrusor overactivity, its use in pelvic floor disorders is still in its infancy. Conclusion: The efficacy of botulinum toxin A for treating pelvic pain, voiding dysfunction, muscle pain and dysfunction, and certain colorectal-related pain issues shows promise but requires additional rigorous evaluation.

Pelvic Organ Prolapse: A Review of In Vitro Testing of Pelvic Support Mechanisms.

Background: Pelvic organ prolapse (POP) affects a significant portion of the female population, impacting quality of life and often requiring intervention. The exact cause of prolapse is unknown. Methods: We review some of the current research that focuses on defining the elements involved in POP, with a focus on in vitro testing. Results: Treatment for POP, ranging from physical therapy or pessary use to more invasive surgery, has varying success rates. This variation is, in part, because the pathophysiology of pelvic floor support-and thus dysfunction-is incompletely understood, particularly regarding the structural components and biomechanical properties of tissue. However, researchers are working to identify and quantify the structural and functional dysfunction that may lead to the development of this condition. Conclusion: Given the limited understanding of prolapse development, more research is needed to quantify the microstructure of the pelvic organs and pelvic support structures, with and without prolapse. Identifying biomechanical properties in multiaxial configurations will improve our understanding of pelvic tissue support, as well as our ability to establish predictive models and improve clinical treatment strategies.

American Urogynecologic Society Systematic Review: The Impact of Weight Loss Intervention on Lower Urinary Tract Symptoms and Urinary Incontinence in Overweight and Obese Women.

OBJECTIVE: Obesity can contribute to urinary symptoms such as urgency, frequency, and incontinence. In addition to classic treatments, weight loss interventions offer a unique clinical opportunity to improve these symptoms. STUDY DESIGN: The American Urogynecologic Society Systematic Review Group conducted a review of articles on the impact of surgical and behavioral weight loss (BWL) interventions on urinary symptoms in overweight and obese women. The certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation criteria. RESULTS: The review group identified 43 publications from 39 studies, including 10 reports that used data from 5 randomized trials. Overall, there is high-certainty evidence that BWL, such as diet and exercise, decreases the prevalence of stress urinary incontinence 15% to 18% and overall urinary incontinence (UI) by 12% to 17% at 1 to 2.9 years. The certainty of evidence on the long-term impact of these interventions was lower. The certainty of the evidence was moderate to low regarding the benefit of BWL on urgency UI and overactive bladder symptoms. No randomized trials evaluated the impact of surgical weight loss on urinary symptoms, and the certainty of evidence of other study types was very low. CONCLUSIONS: There is high-certainty evidence that BWL results in modest improvements in stress and overall UI in overweight and obese women at 1 to 2.9 years after the intervention. Robust studies with low risk of bias are needed to assess whether these benefits are maintained over the long term and are associated with adverse events and to assess the impact of surgical weight loss interventions on urinary outcomes in overweight and obese women.

Biaxial biomechanical properties of the nonpregnant murine cervix and uterus.

From a biomechanical perspective, female reproductive health is an understudied area of research. There is an incomplete understanding of the complex function and interaction between the cervix and uterus. This, in part, is due to the limited research into multiaxial biomechanical functions and geometry of these organs. Knowledge of the biomechanical function and interaction between these organs may elucidate etiologies of conditions such as preterm birth. Therefore, the objective of this study was to quantify the multiaxial biomechanical properties of the murine cervix and uterus using a biaxial testing set-up. To accomplish this, an inflation-extension testing protocol (n = 15) was leveraged to quantify biaxial biomechanical properties while preserving native matrix interactions and geometry. Ultrasound imaging and histology (n = 10) were performed to evaluate regional geometry and microstructure, respectively. Histological analysis identified a statistically significant greater collagen content and significantly smaller smooth muscle content in the cervix as compared to the uterus. No statistically significant differences in elastic fibers were identified. Analysis of bilinear fits revealed a significantly stiffer response from the circumferentially orientated ECM fibers compared to axially orientated fibers in both organs. Bilinear fits and a two-fiber family constitutive model showed that the cervix was significantly less distensible than the uterus. We submit that the regional biaxial information reported in this study aids in establishing an appropriate reference configuration for mathematical models of the uterine-cervical complex. Thus, may aid future work to elucidate the biomechanical mechanisms leading to cervical or uterine conditions.

Smooth muscle regional contribution to vaginal wall function.

Pelvic organ prolapse is characterized as the descent of the pelvic organs into the vaginal canal. In the USA, there is a 12% lifetime risk for requiring surgical intervention. Although vaginal childbirth is a well-established risk factor for prolapse, the underlying mechanisms are not fully understood. Decreased smooth muscle organization, composition and maximum muscle tone are characteristics of prolapsed vaginal tissue. Maximum muscle tone of the vaginal wall was previously investigated in the circumferential or axial direction under uniaxial loading; however, the vaginal wall is subjected to multiaxial loads. Further, the contribution of vaginal smooth muscle basal (resting) tone to mechanical function remains undetermined. The objectives of this study were to determine the contribution of smooth muscle basal and maximum tone to the regional biaxial mechanical behaviour of the murine vagina. Vaginal tissue from C57BL/6 mice was subjected to extension-inflation protocols (n = 10) with and without basal smooth muscle tone. Maximum tone was induced with KCl under various circumferential (n = 5) and axial (n = 5) loading conditions. The microstructure was visualized with multiphoton microscopy (n = 1), multiaxial histology (n = 4) and multiaxial immunohistochemistry (n = 4). Smooth muscle basal tone decreased material stiffness and increased anisotropy. In addition, maximum vaginal tone was decreased with increasing intraluminal pressures. This study demonstrated that vaginal muscle tone contributed to the biaxial mechanical response of murine vaginal tissue. This may be important in further elucidating the underlying mechanisms of prolapse, in order to improve current preventative and treatment strategies.

Cervical pathways for racial disparities in preterm births: the Preterm Prediction Study.

Purpose: Racial disparities in preterm birth have been long recognized, but the social and biological mechanisms for these differences are unclear. Our analysis had three goals: (1) to determine the relation between race and other social risk factors and cervical structure; (2) to determine whether social factors mediate the relation between race and cervical structure; and (3) to determine whether racial disparities in preterm birth (PTB) are mediated through changes in cervical structure observed earlier in pregnancy. Materials and methods: Data from the Maternal Fetal Medicine Unit network Preterm Prediction Study were used to examine the relation between race and other social factors and cervical properties throughout pregnancy in 2920 black and white women. Outcomes included cervical length and dilation; cervical score (cervical length-internal dilation); and whether membranes protruded at 22-24 and 26-29 weeks. Race, education, income, insurance type, and marital status were examined as predictors of the outcomes using linear and logistic regression, adjusting for age, BMI, parity, and smoking. Mediation analysis was used to examine whether (a) any social factors explained racial differences in cervical properties, and (b) whether cervical properties mediated racial differences in risk for preterm birth. Results: Shorter cervical length, especially at a subject's first visit, was associated with black race (adjusted beta -1.56 mm, p < .01) and lower income (adjusted beta -1.48, p =.05). External dilation was not associated with social factors, while internal dilation was associated with black race and lower education. Black race and marital status were associated with lower cervical score. There was no evidence of mediation of the racial effect on cervical properties by any social factor. Shorter cervical length, dilation, and score were all associated with preterm birth (p < .01). Mediation analysis indicated that each of these mediated the effect of race, but explained a small proportion of the total effect (15-25%). Conclusions: Race, and, to a lesser extent, other social factors are correlated with adverse cervical properties. This pathway could explain a proportion of the racial disparity in preterm birth.

Evaluating residual strain throughout the murine female reproductive system.

Mounting evidence suggests that cells within soft tissues seek to maintain a preferred biomechanical state. Residual stress is defined as the stress that remains in a tissue when all external loads are removed and contributes to tissue mechanohomeostasis by decreasing the transmural gradient of wall stress. Current computational models of pelvic floor mechanics, however, often do not consider residual stress. Residual strain, a result of residual stress can be quantitatively measured through opening angle experiments. Therefore, the objective of this study is to quantify the regional variations in opening angles along the murine female reproductive system at estrus and diestrus, to quantify residual strain in the maintenance state of sexually mature females. Further, evidence suggests that hydrophilic glycosaminoglycan/proteoglycans are integral to cervical remodeling. Thus, variations in opening angles following hypo-osmotic loading are evaluated. Opening angle experiments were performed along the murine reproductive system in estrus (n = 8) and diestrus (n = 8) and placed in hypo-osmotic solution. Measurements of thickness and volume were also obtained for each group. Differences (p < 0.05) in opening angle were observed with respect to region and loading, however, differences with respect to estrous stage were not significant. Thickness values were significant (p < 0.05) with respect to region only. The effects of both estrous cycle and region resulted in significant differences (p < 0.05) in observed volume. The observed regional differences indicate variation in the stress-free state among the reproductive system which may have implications for future computational models to advance women's reproductive health.

Effects of Elastase Digestion on the Murine Vaginal Wall Biaxial Mechanical Response.

Although the underlying mechanisms of pelvic organ prolapse (POP) remain unknown, disruption of elastic fiber metabolism within the vaginal wall extracellular matrix (ECM) has been highly implicated. It has been hypothesized that elastic fiber fragmentation correlates to decreased structural integrity and increased risk of prolapse; however, the mechanisms by which elastic fiber damage may contribute to prolapse are poorly understood. Furthermore, the role of elastic fibers in normal vaginal wall mechanics has not been fully ascertained. Therefore, the objective of this study is to investigate the contribution of elastic fibers to murine vaginal wall mechanics. Vaginal tissue from C57BL/6 female mice was mechanically tested using biaxial extension-inflation protocols before and after intraluminal exposure to elastase. Elastase digestion induced marked changes in the vaginal geometry, and biaxial mechanical properties, suggesting that elastic fibers may play an important role in vaginal wall mechanical function. Additionally, a constitutive model that considered two diagonal families of collagen fibers with a slight preference toward the circumferential direction described the data reasonably well before and after digestion. The present findings may be important to determine the underlying structural and mechanical mechanisms of POP, and aid in the development of growth and remodeling models for improved assessment and prediction of changes in structure-function relationships with prolapse development.

Biaxial Mechanical Assessment of the Murine Vaginal Wall Using Extension-Inflation Testing.

Progress toward understanding the underlying mechanisms of pelvic organ prolapse (POP) is limited, in part, due to a lack of information on the biomechanical properties and microstructural composition of the vaginal wall. Compromised vaginal wall integrity is thought to contribute to pelvic floor disorders; however, normal structure-function relationships within the vaginal wall are not fully understood. In addition to the information produced from uniaxial testing, biaxial extension-inflation tests performed over a range of physiological values could provide additional insights into vaginal wall mechanical behavior (i.e., axial coupling and anisotropy), while preserving in vivo tissue geometry. Thus, we present experimental methods of assessing murine vaginal wall biaxial mechanical properties using extension-inflation protocols. Geometrically intact vaginal samples taken from 16 female C57BL/6 mice underwent pressure-diameter and force-length preconditioning and testing within a pressure-myograph device. A bilinear curve fit was applied to the local stress-stretch data to quantify the transition stress and stretch as well as the toe- and linear-region moduli. The murine vaginal wall demonstrated a nonlinear response resembling that of other soft tissues, and evaluation of bilinear curve fits suggests that the vagina exhibits pseudoelasticity, axial coupling, and anisotropy. The protocols developed herein permit quantification of biaxial tissue properties. These methods can be utilized in future studies in order to assess evolving structure-function relationships with respect to aging, the onset of prolapse, and response to potential clinical interventions.

Does bariatric surgery affect urinary incontinence?

OBJECTIVE: To determine International Classification of Disease, 9th Revision, (ICD-9) coding patterns as a proxy for incidence and prevalence of urinary incontinence (UI) in a population of patients before and after a bariatric surgical procedure for the treatment of obesity. METHODS: We evaluated claims from a national private insurer over a 5-year period (2002-2006) to identify female patients who underwent bariatric surgery and had 3 years of follow-up claims data. The cohort of patients who underwent bariatric surgery (treatment) was matched to a cohort of obese female patients who did not undergo bariatric surgery (control), who were followed from the start of their enrollment. UI was identified by ICD-9 coding. RESULTS: After bariatric surgery, 62.4% of patients (83/133) diagnosed with UI before their surgery no longer had a coding diagnosis of UI. In contrast, only 42.1% (56/133) of those in the nonbariatric surgery cohort lost their coding diagnosis of UI (P = .0009). Of those that did not have pre-existing UI, 6.2% (235/3765) of the bariatric surgery cohort gained a new coding diagnosis of UI vs 7.1% (269/3765) of the control group (P = .1169). Our final model suggested that age >45 years (P <.0001) and pre-existing UI (P <.0001) were significantly associated with post-index date UI. Interaction between bariatric surgical status and UI was also significant (P <.0001). CONCLUSION: Patients who undergo bariatric surgery are more likely to lose a previous diagnosis of UI than are obese patients not treated with bariatric surgery. This supports the fact that bariatric surgery may have other indirect benefits to the obese population.

Joint hypermobility, obstetrical outcomes, and pelvic floor disorders.

INTRODUCTION AND HYPOTHESIS: Benign joint hypermobility syndrome may be a risk factor for pelvic floor disorders. It is unknown whether hypermobility impacts the progress of childbirth, a known risk factor for pelvic floor disorders. Our objective was to investigate the association between joint hypermobility syndrome, obstetrical outcomes, and pelvic floor disorders. Our hypotheses were: (1) women with joint hypermobility are less likely to experience operative delivery and prolonged second-stage labor; and (2) pelvic floor disorders are associated with benign hypermobility syndrome, controlling for obstetrical history. METHODS: Joint hypermobility was measured in 587 parous women (participants in a longitudinal cohort study of pelvic floor disorders after childbirth). Their obstetrical histories were obtained from review of hospital records. Pelvic floor disorders were assessed using validated questionnaires and a structured examination for prolapse. Joint hypermobility and pelvic floor disorders were evaluated at enrollment (5-10 years after first delivery). We compared obstetrical outcomes and pelvic floor disorders between women with and without joint hypermobility, defined as a Beighton score ≥ 4. RESULTS: Hypermobility was diagnosed in 46 women (7.8 %) and was associated with decreased odds of cesarean after complete cervical dilation or operative vaginal delivery [odds ratio (OR)=0.51; 95 % confidence interval (CI):0.27-0.95]. Anal sphincter laceration was unlikely to occur in women with hypermobility (OR=0.19; 95 % CI 0.04-0.80). However, hypermobility was not associated with any pelvic floor disorder considered. CONCLUSIONS: Benign joint hypermobility syndrome may facilitate spontaneous vaginal birth but does not appear to be a risk factor for pelvic floor disorders in the first decade after childbirth.

Recurrent pelvic organ prolapse in a patient with history of bladder exstrophy.

BACKGROUND: Increased risk of pelvic organ prolapse in women with a history of bladder exstrophy poses difficult management owing to the absence of anterior support and pelvic angle. We present a case of recurrent prolapse in the setting of bladder exstrophy and discuss factors that may warrant consideration during the evaluation of such patients. CASE: A 26-year-old nulliparous woman with a history of bladder exstrophy and pelvic organ prolapse initially repaired with a porcine graft sacral hysteropexy presented with suspected recurrent apical prolapse. After counseling, she elected to undergo second surgery. During exploration, cervical elongation rather than recurrent prolapse was noted. Therefore, the decision was made to perform a trachelectomy. CONCLUSIONS: When recurrent pelvic organ prolapse is reported, especially in the setting of complicating factors such as a history of bladder exstrophy, other differential diagnoses for prolapse, such as cervical elongation, should be considered. Initial evaluation of such patients can be tailored to evaluate for other possible diagnoses, clarifying the choice of options for optimal medical or surgical management.

Pelvic floor disorders 5-10 years after vaginal or cesarean childbirth.

OBJECTIVE: To estimate differences in pelvic floor disorders by mode of delivery. METHODS: We recruited 1,011 women for a longitudinal cohort study 5-10 years after first delivery. Using hospital records, we classified each birth as: cesarean without labor, cesarean during active labor, cesarean after complete cervical dilation, spontaneous vaginal birth, or operative vaginal birth. At enrollment, stress incontinence, overactive bladder, anal incontinence, and prolapse symptoms were assessed with a validated questionnaire. Pelvic organ support was assessed using the Pelvic Organ Prolapse Quantification system. Logistic regression analysis was used to estimate the relative odds of each pelvic floor disorder by obstetric history, adjusting for relevant confounders. RESULTS: Compared with cesarean without labor, spontaneous vaginal birth was associated with a significantly greater odds of stress incontinence (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.5-5.5) and prolapse to or beyond the hymen (OR 5.6, 95% CI 2.2-14.7). Operative vaginal birth significantly increased the odds for all pelvic floor disorders, especially prolapse (OR 7.5, 95% CI 2.7-20.9). These results suggest that 6.8 additional operative births or 8.9 spontaneous vaginal births, relative to cesarean births, would lead to one additional case of prolapse. Among women delivering exclusively by cesarean, neither active labor nor complete cervical dilation increased the odds for any pelvic floor disorder considered, although the study had less than 80% power to detect a doubling of the odds with these exposures. CONCLUSION: Although spontaneous vaginal delivery was significantly associated with stress incontinence and prolapse, the most dramatic risk was associated with operative vaginal birth. LEVEL OF EVIDENCE: II.

Teaching subcuticular suturing to medical students: video versus expert instructor feedback.

OBJECTIVE: Given limitations in surgical educational resources, more efficient teaching methods are needed. We sought to evaluate 3 strategies for improving skills in subcuticular suturing-practice with an instructional video, practice with expert instructor supervision, and independent practice. DESIGN: Fifty-eight medical students volunteered for this research. Students viewed a video on subcuticular suturing then completed a pretest requiring closure of an incision in a plastic model. Students were randomized among 3 groups: practice with an instructional video (group A), practice with supervision by an expert instructor (group B), and independent practice (group C). After instruction, students completed a posttest, then a retention test 1 week later. Their performances were video recorded and evaluated using a validated scoring instrument composed of global and task-specific subscales. RESULTS: Performances measured using both subscales improved significantly from pretest to post-test only for group B. However, when comparing student performances between pretest and retention posttest, significant improvements on both subscales were seen only in group A. CONCLUSION: These results suggest that practice with an instructional video is an effective method for acquiring skill in subcuticular suturing.