Relationship between intra-abdominal pressure and vaginal wall movements during Valsalva in women with and without pelvic organ prolapse: technique development and early observations.

OBJECTIVES: To develop and test a method for measuring the relationship between the rise in intra-abdominal pressure and sagittal plane movements of the anterior and posterior vaginal walls during Valsalva in a pilot sample of women with and without prolapse. METHODS: Mid-sagittal MRI images were obtained during Valsalva while changes in intra-abdominal pressure were measured via a bladder catheter in 5 women with cystocele, 5 women with rectocele, and 5 controls. The regional compliance of the anterior and posterior vagina wall support systems were estimated from the ratio of displacement (mm) of equidistant points along the anterior and posterior vaginal walls to intra-abdominal pressure rise (mmHg). RESULTS: The compliance of both anterior and posterior vaginal wall support systems varied along different regions of vaginal wall for all three groups, with the highest compliance found near the vaginal apex and the lowest near the introitus. Women with cystocele had more compliant anterior and posterior vaginal wall support systems than women with rectocele. The movement direction differs between cystocele and rectocele. In cystocele, the anterior vaginal wall moves mostly toward the vaginal orifice in the upper vagina, but in a ventral direction in the lower vagina. In rectocele, the direction of the posterior vaginal wall movement is generally toward the vaginal orifice. CONCLUSIONS: Movement of the vaginal wall and compliance of its support is quantifiable and was found to vary along the length of the vagina. Compliance was greatest in the upper vagina of all groups. Women with cystocele demonstrated the most compliant vaginal wall support.

On pelvic reference lines and the MR evaluation of genital prolapse: a proposal for standardization using the Pelvic Inclination Correction System.

Five midsagittal pelvic reference lines have been employed to quantify prolapse using MRI. However, the lack of standardization makes study results difficult to compare. Using MRI scans from 149 women, we demonstrate how use of existing reference lines can systematically affect measurements in three distinct ways: in oblique line systems, distances measured to the reference line vary with antero-posterior location; soft issue-based reference lines can underestimate organ movement relative to the pelvic bones; and systems defined relative to the MR scanner are affected by intra- and interindividual differences in the pelvic inclination angle at rest and strain. Thus, we propose a standardized approach called the Pelvic Inclination Correction System (PICS). Based on bony structures and the body axis, the PICS system corrects for variation in pelvic inclination, at rest of straining, and allows for the standardized measurement of organ displacement in the direction of prolapse.

Changes in self-assessment of continence status between telephone survey and subsequent clinical visit.

AIMS: To explore variance in reporting continence information obtained by telephone survey with face-to-face clinician interview in a clinical setting. METHODS: As part of a cross-sectional, epidemiologic study of incontinence prevalence among Black and White women aged 35-64 years, randomly selected households were contacted from geographic areas of known racial composition. Of 2,814 women who completed a 20-min, 137-item telephone interview, 1,702 were invited for future components of the study. A subset of these women was recruited for a clinical evaluation that was conducted within a mean of 82 days (SD 38 days) following the interviews. Prior to urodynamics testing, a clinician interview was conducted inquiring about continence status. The criterion for incontinence for both the telephone interview and the clinician interview was constant: 12 or more episodes of incontinence per year. Women whose subjective reports of continence information differed between telephone and clinician interviews were designated as "switchers." RESULTS: Of the 394 women (222 Black and 172 White) who completed the clinical portion, 24.6% (n = 97) were switchers. Switchers were four times more likely to change from continent to incontinent (80.4%, N = 78) than from incontinent to continent (19.4%, N = 19; P = 0.000) and nearly three times more likely to be Black (69%, N = 67) than White (31%, N = 30; P = 0.001). Telephone qualitative interviews were completed with 72 of the switchers. The primary reason for switching was changes in women's life circumstances such as variation in seasons, activities of daily living, and health status followed by increased awareness of leakage secondary to the phone interview. CONCLUSION: One-time subjective telephone interviews assessing incontinence symptoms may underestimate the prevalence of incontinence especially among Black women.

Test-retest reliability of an instrumented speculum for measuring vaginal closure force.

AIMS: The study aimed to: a) determine reliability of an instrumented speculum designed for measuring intravaginal closure pressure, and b) compare findings with a comparable device reported in the literature. The goal of these new devices is to reduce subjectivity, improve precision, and acknowledge reliability issues in quantifying levator ani closure force acting on the vagina. METHODS: The instrumented speculum consisted of two parallel aluminum bills, similar in size to a Peterson speculum. Strain gages located near the root of each bill measure the magnitude of force exerted in the distal vagina. A contraction of the "U-shaped" levator ani muscle closes the levator hiatus with resultant reaction force measured by the speculum in the mid-sagittal plane. We tested the device in twelve nulliparous women making repeated measures within and across 3 different visit days. All measures were made by the same investigator. RESULTS: Same day measures were repeatable within +/-3.8 N by the third visit, with lesser repeatability on the 1st and 2nd visit days. Across days, repeatability was improved by Visits 2 and 3 with a coefficient of repeatability between those days of +/-5.5 N. Better repeatability was obtained using averaged scores rather than 'best effort' ; but average scores can underestimate best effort. CONCLUSION: Reasonable within-visit repeatability was found. Across-visit repeatability is consistent with the known difficulty that women have in maximally isolating and activating their levator ani muscles. The results corroborate the repeatability results of Dumoulin et al. [2004] using a similar type of dynamometer.

Revisiting reliability of quantified perineal ultrasound: Bland and Altman analysis of a new protocol for the rectangular coordinate method.

AIMS: This study tested the reliability of a new protocol for the rectangular coordinate method of quantifying perineal ultrasound. METHODS: Representative scans of healthy primiparous females were quantified by positioning a pubic bone template, drawn onto an acetate sheet containing x-y axes, over scans, by aligning the x-axis with the pubic bone central axis. Values for x (D(x)) and y (D(y)) located the urethrovesical junction (UVJ) at Rest, and at maximal Valsalva and Kegel. Range of motion (V-K) was calculated. Bland and Altman analysis, correlations, and t-tests determined intra- and inter-rater reliability, and variance due to designation of the pubic bone central axis (template control). RESULTS: Correlations averaged 0.72, 0.70, and 0.92 for intra-rater, inter-rater, and template control experiments. D(x) Rest, D(x) Kegel, and V-K were reliable in all experiments. First and second measures for inter-rater D(y) Rest and D(y) Kegel, and template control D(y) Valsalva were significantly different. Bland and Altman analysis showed D(y) Rest, D(y) Kegel, and D(x) and D(y) Valsalva for both reliability experiments to have limits of agreement (LOA's) large enough to explain >or=50% of the actual value ranges. Template control LOA's explained

Measurement of the pubic portion of the levator ani muscle in women with unilateral defects in 3-D models from MR images.

OBJECTIVE: Develop a method to quantify the cross-sectional area of the pubic portion of the levator ani muscle, validate the method in women with unilateral muscle defects, and report preliminary findings in those women. METHOD: Multi-planar proton density magnetic resonance images of 12 women with a unilateral defect in the pubic portion of their levator ani were selected from a larger study of levator ani muscle anatomy in women with and without genital prolapse. Three-dimensional bilateral models of the levator ani were reconstructed (using 3-D Slicer, version 2.1b1) and divided into iliococcygeal and pubic portions. Muscle cross-sectional areas were calculated at four equally spaced locations perpendicular to a line drawn from the pubic origin to the visceral insertion using the I-DEAS computer modeling software. RESULTS: The cross-sectional area of the muscle on the side with the defect was smaller than the normal side at all the four locations. The average bilateral difference was up to 81% at location 1 (nearest pubic origin). Almost all of the volume difference (13.7%, P=0.0004) was attributable to a reduction in the pubic portion (24.6%, P<0.0001), not the iliococcygeal portion (P=0.64), of the muscle. CONCLUSIONS: A method was developed to quantify cross-sectional area of the pubic portion of the levator ani perpendicular to the intact muscle direction. Significant bilateral cross-sectional area differences were found between intact and defective muscles in women with a unilateral defect.

Selecting suspension points and excising the vagina during Michigan four-wall sacrospinous suspension.

OBJECTIVE: To describe the variations in the location of the vaginal apex and the length of vagina excised in women undergoing the Michigan four-wall sacrospinous suspension for posthysterectomy vaginal vault prolapse. METHODS: A prospective observational study of 76 women who had the Michigan modification sacrospinous suspension performed between 1998 and 2001 for posthysterectomy vaginal vault prolapse was carried out. Demographics and preoperative, operative, and postoperative findings were noted, including the pelvic organ prolapse quantification score. The locations of the suspension points relative to the hysterectomy scar were recorded. The amount of vagina excised at surgery and the pre- and postoperative vaginal lengths are reported. RESULTS: The mean length and standard deviation of vagina excised was 4.6 +/- 2.5 cm. The apex created at sacrospinous fixation was at the hysterectomy scar in only seven women (9%). It was most often situated behind the hysterectomy scar, in 58 cases (76%); it was situated in front of it in 11 (14%). In seven women no vagina was excised, and in the remaining 69 women a mean length of 5.1 +/- 2.2 cm was removed. The mean vaginal lengths were 9.7 +/- 1.7 cm preoperatively and 9.4 cm +/- 0.8 postoperatively, a 0.3-cm difference. CONCLUSION: When one performs the Michigan modification sacrospinous suspension, the chosen suspension points are often not at the hysterectomy scar, and in women with large prolapses excess vagina frequently is excised without compromising postoperative vaginal length.

Differences in pelvic floor area between African American and European American women.

OBJECTIVE: This study tests the null hypothesis that the size of the pelvic opening spanned by the pelvic floor is the same in African American and European American women. STUDY DESIGN: Forty African American female pelvises were age matched with 40 European American female pelvises from the Hamann-Todd collection at the Cleveland Museum of Natural History. The distances between the anchoring points of the pelvic floor to the bony pelvis (pubis anteriorly, ischial spines laterally, and inferior lateral angle of the sacrum posteriorly) were measured on each half of the pelvis. Measurements from left and right halves were averaged. The cross-sectional area of the pelvic floor was calculated from these dimensions. The bi-ischial line divided the total area into anterior and posterior pelvic floor areas. Analyses taking into account differences in stature by dividing individual dimensions by height were also performed. Group differences were compared with the Student t test and the Mann-Whitney rank sum test. RESULTS: African American women had a 5.1% smaller pelvic floor area than European American women (889.6 cm(2) vs 937.0 cm(2), 5.1% P =.037). This was attributable to a 10.4% smaller posterior area (365.3 cm(2) vs 407.6 cm(2), 10.4% P =.016), whereas the anterior areas were similar (524.3 cm(2) vs 529.3 cm(2), P =.61). The following measured distances were smaller in African American women: ischial spine to inferior sacral angle (5.4 cm vs 5.9 cm, P =.016) and bi-ischial diameter (10.0 cm vs 10.6 cm, P =.004). These distances remained significant after height was controlled. CONCLUSIONS: In African American women, the posterior pelvic floor area is 10.4% smaller than in European American women, resulting in a 5.1% smaller total pelvic floor area.

A structured system to evaluate urethral support anatomy in magnetic resonance images.

OBJECTIVE: To develop a systematic method for analyzing the normal magnetic resonance imaging location and appearance of structural features involved in urethral support. STUDY DESIGN: Multiplanar proton density magnetic resonance images of 50 nulliparous women were made at 0.5-cm intervals. The arcuate pubic ligament was the chosen reference point in all views. Structural features were located by identification of the magnetic resonance images in which they appeared. The presence or absence of urethral support structures in each scan level relative to the arcuate pubic ligament was evaluated and recorded as a graphic display. Support structures examined were the arcus tendineus fasciae pelvis, the perineal membrane, the pubococcygeal levator ani muscle and its vaginal and bony attachments, and the pubovesical muscle. Structural definitions were developed on the basis of established periurethral anatomy. Two examiners independently assessed 10 scans for interobserver concordance. This system was used in nulliparous women to quantify the location of magnetic resonance visible structures. RESULTS: Because all levels were 0.5 cm apart, slice identification represented the distance above the arcuate pubic ligament (eg, 2 images above the arcuate pubic ligament or 1.0 cm). Interobserver concordance was 88% in identification of structure location. In the axial plane, specific structural features and relationships were localized. The frequency at which a specific structure was observed at a specific image level in all women was depicted as a gray density within the graphic display. These frequencies indicated where we would expect each structure to be located in healthy women. Relationships between structures and their attachments became apparent. Consideration of expected structural locations proven by nulliparous scans will enable us to quantitatively define abnormal structures in parous women. CONCLUSIONS: This systematic magnetic resonance evaluation allows, for the first time, quantification of the normal anatomic location of urethral support structures. It can be used to help identify the difference between structural abnormalities and normal variation in parous women.

On-screen vector-based ultrasound assessment of vesical neck movement.

OBJECTIVE: We sought to develop a vector-based assessment to determine the magnitude and direction of bladder neck movements, as well as to assess whether probe movement relative to the pubis needs to be taken into account. STUDY DESIGN: Ten nulliparous continent, 10 primiparous continent, and 10 primiparous stress-incontinent women were recruited. Perineal ultrasound scanning was performed in standing women while they were resting, performing the Valsalva maneuver, coughing, and performing Kegel exercises. A direct on-screen assessment of bladder neck displacement from rest to the peak of dynamic activity relative to the pubic axis was made. Transducer movement was assessed by measuring the displacement of the pubic bone. RESULTS: The method was feasible because measurements were possible in all 30 subjects. Vesical neck and pubic point movement in millimeters (+/- SD) and the percentage error if pubic point movement is not accounted for are as follow: strain, vesical neck 16.9 +/- 6.1 and pubic point 4.8 +/- 3.9, 28%; cough, vesical neck 10.2 +/- 5.4, pubic point 2.9 +/- 3.4, 33%; Kegel exercise, vesical neck 7.0 +/- 3.6 and pubic point 0.7 +/- 1.4, 37%. Similar discrepancies in angle were found and are presented. Uncorrected direction of vesical neck and pubic point movement in degrees and the percentage error if pubic point movement is not accounted for are as follow: strain, vesical neck 169.4 +/- 18.5 and pubic point 214.0 +/- 56.7, 18%; cough, vesical neck 162.0 +/- 12.8, pubic point 238.4 +/- 27.4, 22%; Kegel exercise, vesical neck -0.9 +/- 12.7 and pubic point -4.8 +/- 20.6, 87%. Test-retest reliability correlations were more than an r value of 0.7 in all measures and 86% of the measurements greater than 0.8. CONCLUSION: The vector-based system provides a simple method for quantifying distance and direction of vesical neck motion, as well as localizing the resting vesical neck position.

Pelvic muscle activity in nulliparous volunteers.

The aim of this study was to describe normal characteristics of spontaneous and voluntary pelvic muscle function in nulliparous healthy continent women and to assess the reaction of the pelvic floor to stress and fatigue. Ten nulliparous volunteers were recruited. Pelvic muscle strength was evaluated by palpation and perineal ultrasound. Kinesiological EMG and perineal ultrasound were performed to test for possible fatigue and to assess bladder neck mobility during coughing with a pre-contraction of the pelvic floor muscles. Bladder neck mobility did not increase after attempts to fatigue the pelvic floor muscles. Bladder neck descent was significantly less when the women were instructed to contract the pelvic floor muscles before coughing. The contraction of the pelvic floor muscles stabilizes the vesical neck in nulliparous women.

The functional anatomy of the female pelvic floor and stress continence control system.

This paper provides an overview of the functional anatomy of the structures responsible for controlling urinary continence under stress. The stress continence control system can be divided into two parts: the system responsible for bladder neck support, and the system responsible for sphincteric closure. Age- and injury-related changes in each of these systems are discussed. Understanding the pathophysiology of incontinence on the anatomical level will help to lead to identification of specific defects, thereby allowing better individualized treatment for the incontinent patient.

Visibility of pelvic organ support system structures in magnetic resonance images without an endovaginal coil.

OBJECTIVE: The aim of this study was to determine which elements of the pelvic organ support system are visible on magnetic resonance imaging performed without an endovaginal coil. STUDY DESIGN: Proton density-weighted pelvic magnetic resonance images were obtained for 20 healthy continent nulliparous women with a mean (+/-SD) age of 30.1 +/- 5.1 years (range, 22-42 years). Standardized analyses of transverse, coronal, and sagittal key images were carried out to describe pelvic organ support system anatomy. RESULTS: Details of both the muscular and fascial supports were clearly seen. The endopelvic fascia was visible on transverse images and could be seen to laterally attach the proximal vagina to the pelvic wall. Its appearance was consistent with its composition of a network of connective tissue, vessels, and nerves. The upward, lateral, and dorsal direction of its most cephalic suspending fibers was visible on both transverse and coronal images. The different nature of the uterosacral ligament relative to the cardinal ligaments was also demonstrated in transverse images. The endopelvic fascia's attachment to the pelvic walls was visible in the midvagina. The 3 parts of the levator ani muscle were likewise visible-the pubococcygeus, puborectalis, and iliococcygeus. Fusion of the levator ani muscle and the vagina at the level of the middle urethra could be recognized on transverse and coronal images. CONCLUSION: Magnetic resonance imaging depicted structures of the pelvic organ supports, including the endopelvic fascia and pelvic floor muscles, without the need for an endovaginal coil.

Bladder neck mobility in continent nulliparous women.

OBJECTIVE: To evaluate the mobility of the vesical neck during coughing and valsalva in healthy nulliparous volunteers and to test the reliability of the technique applied. DESIGN: Clinical observational study. SETTING: Department of Obstetrics and Gynaecology, Cantonal Hospital Lucerne, Switzerland. POPULATION: Thirty-nine nulliparous volunteers. METHODS: Vesical neck motion was assessed with perineal ultrasound. Intra-abdominal pressure was controlled for with an intrarectal probe. Intra-rater reliability was evaluated. RESULTS: Vesical neck mobility was significantly lower during coughing (8 mm, SD 4 mm) than during valsalva (15 mm, SD 10 mm) (P < 0.005). Between individuals mobility varied from 4 mm to 32 mm during coughing and from 2 mm to 31 mm during valsalva. Test-retest-studies showed a maximum difference between to tests during coughing of 4 mm and during valsalva of 5 mm. CONCLUSION: The bladder neck is mobile in normal continent women and bladder neck mobility is lower during coughing than during Valsalva.

Pelvic floor muscle contraction during a cough and decreased vesical neck mobility.

OBJECTIVE: To test the hypothesis that a voluntary pelvic muscle contraction initiated in preparation for a cough, a maneuver we call the Knack, significantly reduces vesical neck displacement. METHODS: A convenience sample of 22 women consisted of 11 young, continent nulliparas (mean age [+/- standard deviation] 24.8 +/- 7.0 years) and 11 older, incontinent paras (mean age [+/-SD] 66.9 +/- 3.9 years). With the use of perineal ultrasound, we quantified vesical neck displacement at rest and during coughs using caliper tracing and a coordinate system. The subjects coughed with and without voluntary pelvic floor muscle contraction. RESULTS: Vesical neck mobility during coughs was significantly decreased when voluntary contraction was used: from a median (range) of 5.4 (20.0) mm without volitional contraction to 2.9 (18.3) mm with volitional contraction (P <.001). The younger women demonstrated a median (range) decrease in excursion from 4.6 (19.5) to 0.0 (17.0) mm (P =.007), and the older incontinent women demonstrated a median (range) decrease from 6.2 (10.0) to 3.5 (15.4) mm (P =.003). At rest, the median vesical neck position in the group of older incontinent women was significantly further dorsocaudal (P =.001) than in the younger women. CONCLUSION: A pelvic floor muscle contraction in preparation for, and throughout, a cough can augment proximal urethra support during stress, thereby reducing the amount of dorsocaudal displacement.

Urinary tract erosions after synthetic pubovaginal slings: diagnosis and management strategy.

OBJECTIVES: To review our experience with the diagnosis and management of genitourinary tract erosions after pubovaginal sling placement. METHODS: Clinic and operative records from the urology and gynecology services at two university hospitals were reviewed, and 14 patients were identified who underwent surgical treatment for a urogenital tract erosion after pubovaginal sling placement. The presenting symptoms, physical findings, diagnostic procedures, surgical treatments, and outcomes were reviewed. RESULTS: Six vaginal erosions, six urethral and vaginal erosions, and two bladder erosions occurred. All were associated with synthetic sling or suture materials. Common symptoms included vaginal and urethral pain, irritative voiding symptoms, vaginal discharge and/or bleeding, and recurrent urinary tract infections. All vaginal and urethral erosions were detected by physical examination and cystoscopy. Symptoms resolved after removal of the eroded sling component. Of the 12 patients with vaginal or urethral erosions, 7 developed recurrent postoperative stress incontinence. CONCLUSIONS: Persistent painful or irritative symptoms after pubovaginal sling placement may be due to urogenital tract erosion, especially if synthetic materials were used. Appropriate evaluation and treatment will result in dramatic symptomatic improvement, although recurrent stress incontinence may occur.

Differences in perineal lacerations in black and white primiparas.

OBJECTIVE: To test the null hypothesis that there are no differences in incidence of perineal and vaginal lacerations in primiparous black and white women. METHODS: We reviewed University of Michigan Hospital delivery records, from July 1996 to December 1998, of black and white women 18 years and older and at least 35 weeks' gestation who had their first vaginal delivery. Birth weight, episiotomy, gestational age, laceration, length of second stage, oxytocin use, epidural use, and operative vaginal delivery were analyzed by univariable and multivariable tests. RESULTS: We analyzed 176 black women (mean age +/- standard deviation 23.7 +/- 4.7 years; range 18-41 years) and 1633 white women (27.8 +/- 5.4 years; 18-49 years; P <.001). Black women were less likely to have second, third, or fourth degree lacerations (43% compared with 59%; P <.001). The mean length of second stage of labor was shorter in the black women (73 +/- 69 minutes; range 3-494 minutes compared with 106 +/- 78 minutes; range 2-642 minutes; P <.001). Infants of black women weighed less (3292 +/- 490 g; 1990-5190 g compared with 3429 +/- 470 g; 1860-4950 g; P <.001). Multivariable analysis showed that black women were twice as likely to deliver with intact perineums than white women (P <.001). CONCLUSION: Black primiparas were less likely to deliver with second-degree or greater lacerations and more likely to deliver with their perineums intact.

Quantification of intramuscular nerves within the female striated urogenital sphincter muscle.

OBJECTIVE: To analyze the quantity and distribution of intramuscular nerves within the striated urogenital sphincter and test the hypothesis that decreased nerve density is associated with decreased striated sphincter muscle and cadaver age. METHODS: Thirteen cadaveric urethras (mean age 47 years, range 15-78 years) were selected for study. A sagittal histologic section was stained with S100 stain to identify intramuscular nerves. The number of times that a nerve was seen within the striated urogenital sphincter (nerve number) was counted. The number of axons within each nerve fascicle was also counted. Regression analysis of nerve density against muscle cell number and age was performed. RESULTS: Remarkable variation was found in the quantity of intramuscular nerves in the striated urogenital sphincter of the 13 urethras studied. The number of nerves ranged from 72 to 543, a sevenfold variation (mean 247.1 +/- standard deviation 123.2), and the range of number of axons was 431 to 3523 (2201 +/- 1152.6). The larger nerve fascicles were seen predominantly in the distal (13.1 +/- 5.7 axons per nerve) compared with the proximal part of the striated urogenital sphincter (1.2 +/- 2). Reduced nerve density throughout the striated urogenital sphincter correlated with fewer muscle cells (P =.02). Nerve density also decreased with advancing age (P =.004). CONCLUSION: Remarkable variation in the quantity of intramuscular nerves was found. Women with sparse intramuscular nerves had fewer striated muscle cells. Intramuscular nerve density declined with age.

Racial differences in the structure and function of the stress urinary continence mechanism.

OBJECTIVE: To compare the structure and function of the urethral sphincter and the urethral support in nulliparous black and white women. METHODS: Eighteen black women (mean age 28.1 years) and 17 white women (mean age 31.3 years) completed this cross-sectional study. The following assessments were made: urethral function using multichannel cystometrics and urethral pressure profilometry, pelvic muscle strength using an instrumented speculum, urethral mobility using the cotton-swab test and perineal ultrasound, and pelvic muscle bulk using magnetic resonance imaging. RESULTS: Black women demonstrated a 29% higher average urethral closure pressure during a maximum pelvic muscle contraction (154 cm H(2)O versus 119 cm H(2)O in the white subjects; P =.008). Although not statistically significant, black women had a 14% higher maximum urethral closure pressure at rest (108 cm H(2)O versus 95 cm H(2)O; P =.23) and a 21% larger urethral volume (4818 mm(3) versus 3977 mm(3); P =.06). In addition, there was a 36% greater vesical neck mobility measured with the cotton-swab test (blacks 49 degrees versus whites 36 degrees; P =.02) and a 42% difference in ultrasonically measured vesical neck mobility during a maximum Valsalva effort (blacks = -17 mm versus whites -12 mm; P =.08). CONCLUSION: Functional and morphologic differences exist in the urethral sphincteric and support system of nulliparous black and white women.