Anatomical and functional changes in the lower urinary tract during pregnancy

What is known about changes in pelvic floor muscle strength and tone in women during the childbirth pathway? A scoping review

INTRODUCTION

This scoping review aims to comprehensively explore the existing research on the changes in pelvic floor function that occur throughout the childbirth pathway (antenatal, intrapartum, and postnatal period). Furthermore, it seeks to identify new opportunities and directions for future research in this field. In particular, this review focuses on investigating pelvic floor muscle strength and tone in women during the childbirth pathway.

METHODS

The following databases were investigated from their inception: PubMed, OVID, Medline, ScienceDirect, The Cochrane Central Library, Scopus, Web of Science, PEDro, Scholar Google, Embase, and CINHAIL. Literature research was carried out from March to October 2022. Records identified through database searching were imported to Covidence. According to Arksey and O'Malley's five-stage scoping review framework, researchers screen titles and abstracts for eligibility and exclude records that do not meet the inclusion criteria.

RESULTS

A total of 40 studies were included in the data extraction phase. These articles underwent a review, with a specific emphasis on examining the tone, strength, and distensibility of the pelvic floor throughout the childbirth pathway. Among the selected studies, 22 investigated pelvic floor strength, 7 the distensibility, and 3 articles the tone.

CONCLUSIONS

This review identified both areas of agreement and disagreement across all three themes examined, with a particular emphasis on labor and the postpartum period. Notably, the review unveiled a significant scarcity of data concerning the tone of pelvic floor muscles throughout the childbirth pathway. Further studies to investigate the relationship between midwifery care and pelvic floor outcomes are required to improve clinical practice.

The Effect of Pregnancy on Urinary Symptoms

Background Urinary incontinence is a condition that causes social, medical, or hygienic problems. The increase in the incidence of stress incontinence, particularly with increasing parity, emphasizes the role of pregnancy on the etiology of incontinence and other urinary symptoms. This study aimed to estimate the effect of pregnancy on urinary incontinence and other urinary symptoms with history and urodynamic data. Methodology This study was conducted at Mustafa Kemal University, Medical Faculty, Obstetrics and Gynecology Department. A total of 72 pregnant primigravid women without any urinary problems were included in the study. Patients with severe chronic disease, neurological disorders, antepartum hemorrhage, multiple pregnancies, younger than 18, and those with physical and mental disabilities were excluded. All patients were initially evaluated in the first trimester and finally in the sixth week of the postpartum period. Demographic and obstetric data, including urological complaints and urodynamic findings, were recorded. Results There were significant increases in nocturia, frequency, dysuria, urgency, and stress urinary incontinence complaints in pregnant women. Urge incontinence was not significantly different after pregnancy. In the postpartum urodynamic studies, nine (12.5%) patients with stress urinary incontinence and six (8.3%) patients with detrusor instability were detected. There was no significant difference between cesarean section and vaginal delivery regarding incontinence. Conclusions According to the study findings, pregnant women who were continent before pregnancy could become incontinent after birth according to urodynamic data. However, long-term studies are needed to determine whether this incontinence is temporary. Additionally, according to our results, cesarean section should not be recommended over vaginal delivery only to prevent incontinence.

Application of Transperineal Pelvic Floor Ultrasound in Changes of Pelvic Floor Structure and Function Between Pregnant and Non-Pregnant Women

Objective

To evaluate the changes of pelvic floor tissue structure and function between pregnant and non-pregnant women from the view of transperineal pelvic floor ultrasound.

Methods

Thirty-eight cases of women with a second singleton pregnancy and thirty-two cases of women with a first singleton pregnancy underwent transperineal pelvic floor ultrasound, and their results were compared with forty-two cases of healthy non-pregnant women.

Results

The differences of bladder neck descent (BND), rectal ampulla distance and levator hiatus area (LHA) among the three groups were statistically significant (P<0.05), and the differences of BND, rectal ampulla distance, LHA between the women with a second singleton pregnancy group and non-pragnent group were statistically significant (P<0.05). The BND, retrovesical angle at rest (RVA-R) and retrovesical angle underwent Valsalva maneuver (RVA-V) in the group of stress urinary incontinence (SUI) during pregnancy were larger than those in non-SUI group, with significant difference (P<0.05), especially BND and RVA-V (P = 0.00).

Conclusion

Transperineal pelvic floor ultrasound has a high resolution of pelvic floor structure and function changes during pregnancy, and can dynamically evaluate pelvic floor function, providing a theoretical basis for early diagnosis and prevention of female pelvic floor dysfunction (FPFD) in subsequent pregnancies.

Trimester-based changes in urogenital symptoms and their impact on the quality of life in pregnant women: A preliminary report

Background:

This study is aimed to determine the trimester-based changes in urogenital symptoms and their impact on the quality of life in pregnant women.

Materials and methods:

Fifty-one pregnant women participated in this study. Self-reported symptom-based questionnaires, Urogenital Distress Inventory-Short Form (UDI-6), Incontinence Severity Index (ISI), and Incontinence Impact Questionnaire (IIQ-7) were administered to determine urogenital symptoms, incontinence severity, and the quality of life in all participants in the first, second, and third trimesters. The findings obtained were analyzed with the Friedman and Spearman tests.

Results:

Irritative (urgency and frequency) and stress incontinence symptoms showed statistically significant changes (p < 0.05), whereas obstructive and genital pain/discomfort symptoms did not significantly change (p > 0.05) according to the scores of UDI-6 subscales over the trimesters. There were negative, weak-moderate correlations between stress incontinence symptoms and IIQ-7 in the first, second, and third trimester. There was a negative, moderate correlation between irritative symptoms and IIQ-7 only in the third trimester, but there were not any correlations between the other urogenital symptoms and IIQ-7 (p > 0.05). In the prepregnancy period, stress urinary incontinence (SUI) and urge urinary incontinence (UUI) occurred in 9.8% and 7.8% of the patients, respectively, whereas there were no women with mixed urinary incontinence (MUI) preconceptionally. The presence of SUI, UUI, and MUI were 13.7%, 7.8%, and 0% in the first, 26%, 9.8%, and 3.9% in the second, and 41.2%, 27.5%, and 13.7% in the third trimester, respectively. ISI scores showed statistically significant changes in the first, second, and third trimesters of women with SUI, UUI, and MUI (p < 0.05). Statistically significant differences were also found in UDI-6 and IIQ-7 scores obtained from all three trimester evaluations of pregnant women with SUI, UUI, and MUI (p < 0.05).

Conclusions:

Urogenital symptoms associated with urinary incontinence such as frequency, urgency, and stress incontinence were found to be increased over the course of the three trimesters of the pregnancy and the quality of life was negatively affected. Special care is essential for urinary incontinence during antenatal care.

The effectiveness of group-based pelvic floor muscle training in preventing and treating urinary incontinence for antenatal and postnatal women: a systematic review

Introduction and hypothesis

Urinary incontinence (UI) is prevalent in antenatal and postnatal women. Pelvic floor muscle training (PFMT) is the first-line treatment for UI. Group-based PFMT provides a way for professionals to deliver this intervention to more women who need to prevent and/or treat UI. This review aims to (1) assess the effectiveness of group-based PFMT in preventing and treating UI in antenatal and postnatal women and (2) explore the characteristics of group-based intervention and factors which had an impact on the success of group-based PFMT.

Methods

Randomized controlled trials (RCTs) were included in this review. A comprehensive search was conducted in PubMed, Embase, Medline, PsycINFO, Maternity and Infant Care Database, CINAHL, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Database and Wanfang Database. The overall quality was assessed using Grading of Recommendations, Assessment, Development and Evaluations (GRADE). RCTs which included pregnant and/or postnatal women with or without UI investigating the effectiveness of group-based PFMT were included.

Results

Five RCTs were included in this review. The overall quality of the results of the included studies was low. Delivering group-based PFMT during pregnancy significantly reduced the prevalence of UI in both the pregnant period [risk ratio (RR) = 0.67, 95% confidence interval (CI) 0.57 to 0.80, P < 0.00001] and the postnatal period [RR = 0.66, 95% CI 0.52 to 0.84, P = 0.0008]. Only one RCT delivered group-based PFMT during the postnatal period.

Conclusion

Evidence of weak quality supports the effectiveness of undertaking group-based PFMT in pregnancy to prevent UI during pregnancy and the postnatal period. No evidence showed the effectiveness of undertaking group-based PFMT in the postnatal period.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00192-021-04960-2.

Musculoskeletal and anthropometric factors associated with urinary incontinence in pregnancy

INTRODUCTION

Urinary incontinence (UI) is a common pelvic floor dysfunction in pregnancy. The relationship between biomechanical changes and pregnancy-related UI has not been fully elucidated.

OBJECTIVE

To investigate the association of various musculoskeletal and anthropometric changes in pregnancy that affect gestational UI.

METHODS

The study was conducted with 275 pregnant women. Ninety-three, 110 and 72 women were in first, second and third trimesters, respectively. Incontinence Impact Questionnaire for UI, Urogenital Distress Inventory-Short Form and Incontinence Severity Index were applied. Lumbar lordosis measurement was performed by Baseline Bubble Inclinometer while diastasis recti abdominis (DRA) measurement was carried out by finger-width method. Manual muscle test for rectus abdominis and right and left external oblique abdominal muscles, and Benign joint hypermobility test with Beighton scoring method were also applied as musculoskeletal measurements. Tape measurement at the waist, umbilical and hip levels, caliper with bi-iliac and bi-trochanteric diameters were also recorded as anthropometric measurements.

RESULTS

Significant associated factors for UI were: umbilical DRA (OR = 1.57; p = .012); rectus abdominis muscle strength (values of 3 and below, OR = 1.2; p = .014); umbilical environment (OR = 1.1; p = .029); bi-iliac diameter (OR = 1.1; p = .05;) and bi-trochanteric diameter (OR = 1.3; p = .05), respectively.

CONCLUSION

Changing musculoskeletal and anthropometric characteristics of pregnant women should be taken into consideration in UI follow-up during pregnancy.

Method and reliability of measuring midurethral area and echogenicity, and changes during and after pregnancy

Introduction and hypothesis

Internal closure of the urethral sphincter is one of the mechanisms in maintaining continence. Little is known about changes in the urethral sphincter during pregnancy. We designed this study to develop a reliable method to measure the area and mean echogenicity of the midurethra during and after pregnancy and to assess changes over time.

Methods

Two observers independently segmented the urethra as follows: in the sagittal plane, the urethra was positioned vertically, the marker was placed in the middle section of the lumen of the urethra, and eight tomographic US images of 2.5 -mm slices were obtained. The central image was selected, and area and mean echogenicity were calculated automatically. Intra- and interobserver reliability were determined by intraclass correlation coefficients (ICC) and their 95% confidence intervals (CI). Two hundred and eighty women underwent TPUS at 12 weeks and 36 weeks of gestation and 6 months postpartum, and 3D/4D transperineal ultrasound (TPUS) images of 40 pregnant nulliparous women were used for the reliability study. Paired t tests were used to assess changes in echogenicity and area.

Results

The ICC for measuring the area was substantial, at 0.77 and for measuring mean echogenicity was almost perfect, at 0.86. In the total study group (n = 280), midurethral area and mean echogenicity were significantly lower 6 months after delivery compared with 12 and 36 weeks of gestation.

Conclusions

Our protocol for measuring area and mean echogenicity of the midurethra is reliable. This study indicates that structural changes in the midurethraoccur during pregnancy.

Gestational Urinary Incontinence in Nulliparous Pregnancy- A Pilot Study

INTRODUCTION

Urinary Incontinence (UI) in pregnancy is more than a disease; it is a social problem that necessitates special care and management. The exact rationales and biological facts behind urinary incontinence during pregnancy are unclear and multivariate.

AIM

This pilot study was designed to examine the direct effect of gestational factors (e.g., physical and metabolic/hormonal) on the presence of Gestational Urinary Incontinence (GUI), in nulliparous pregnant women.

MATERIALS AND METHODS

This was a questionnaire-based study comprising of 61 nulliparous pregnant woman who had not experienced any Urinary Incontinence (UI) before their pregnancies. Patients were examined during their pregnancies within the framework of the antenatal care program continued at the Division of Perinatology, Hacettepe University, Ankara, Turkey, between January 2015 and December 2016. A 'urinary incontinence questionnaire' was used three times during different periods of gestation (11-14, ~24 and ~37 gestational weeks) for each patient. Statistical analysis was performed using the SPSS software version 20.0. The Chi-Square test or Fisher's-exact test was used to compare proportions in groups.

RESULTS

The prevalence of total urinary incontinence (stress urinary incontinence, urge urinary incontinence and mixed urinary incontinence) in nulliparous pregnant women was 4.9% (n=3), 9.8% (n=6) and 26.2% (n=16) at 11-14, ~24 and ~37 gestational weeks, respectively. Stress urinary incontinence was found to be 3.3% (n=2), 6.6% (n=4) and 16.4% (n=10) at 11-14, ~24 and ~37 gestational weeks, respectively. Urge urinary incontinence frequency was found to be 1.6% (n=1), 3.3% (n=2), 6.6% (n=4), and mixed urinary incontinence frequency was 0% (n=0), 0% (n=0), 3.3% (n=2) at 11-14, ~24 and ~37 gestational weeks, respectively. Maternal age, birth weight of the neonate and gestational age at birth had no statistically significant effect on GUI.

CONCLUSION

Urinary incontinence is an important issue during pregnancy and related symptoms are more common in third trimester.

Differences in urinary incontinence symptoms and pelvic floor structure changes during pregnancy between nulliparous and multiparous women

Background

This study was performed to compare changes in urinary incontinence (UI) symptoms and pelvic floor structure during pregnancy between nulliparous and multiparous women.

Methods

A cross-sectional survey was performed among pregnant women from July 2016 to January 2017. In total, 358 pregnant women from two hospitals underwent an interview and pelvic floor transperineal ultrasound assessment. A questionnaire regarding sociodemographic, gynecological, obstetric features and the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) were used for the interview. Imaging data sets were analyzed offline to assess the bladder neck vertical position (BNVP), urethral angles (α, β, and γ angles), and hiatal area (HA) at rest and at maximal Valsalva maneuver (VM).

Results

After excluding 16 women with invalid data, 342 women were included. The prevalence (χ² = 9.15, P = 0.002), frequency (t = 2.52, P = 0.014), usual amount of UI (t = 2.23, P = 0.029) and scores of interference with daily life (t = 2.03, P = 0.045) during pregnancy were higher in multiparous than nulliparous women. A larger bladder neck descent (BND) (F = 4.398, P < 0.001), HA (F = 6.977, P < 0.001), α angle (F = 2.178, P = 0.030), β angle (F = 4.404, P < 0.001), and γ angle (F = 2.54, P = 0.011) at VM were discovered in pregnant women with UI than without UI. Multiparous women had a significantly higher BND (t = 2.269, P = 0.024) and a larger α angle (F = 2.894, P = 0.004), β angle (F = 2.473, P = 0.014), and γ angle (F = 3.255, P = 0.001) at VM than did nulliparous women.

Conclusion

Multiparous women experienced more obvious UI symptoms and pelvic floor structure changes during pregnancy than did nulliparous women.

Urinary incontinence among pregnant women, following antenatal care at University of Gondar Hospital, North West Ethiopia

Background

Urinary incontinence is defined as a complaint of any involuntary leakage of urine. During pregnancy, the prevalence of urinary incontinence ranges from 32 to 64 %. Different factors like demographic factors, obstetric factors, and other external factors affect urinary incontinence. In Ethiopia, there is no study conducted so far on the magnitude of urinary incontinence and factors associated among pregnant women. The objective of this study was to determine the prevalence of urinary incontinence and associated factors among pregnant women following antenatal care at the University of Gondar Hospital.

Methods

Institution based cross- sectional study was conducted among 422 pregnant women following antenatal care at the University of Gondar Hospital. Data was collected using a structured questionnaire and analyzed using SPSS version 20. Descriptive, bivariate, and multivariate analyses were performed. The results were considered significant at p-value < 0.05.

Result

The overall prevalence of urinary incontinence among the participants was 11.4 % [48]. After adjustment episiotomy, constipation, obese women, chronic cough/sneezing, asthma/allergies/sinusitis was associated with urinary incontinence.

Conclusions

In this study, a lower prevalence was found than that of previous studies. There was a significant association of urinary incontinence with a previous history of episiotomy, constipation, maternal BMI, and respiratory problems.

Stress urinary incontinence in pregnant women: a review of prevalence, pathophysiology, and treatment

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most common type of urinary incontinence (UI) in pregnant women and is known to have detrimental effects on the quality of life in approximately 54.3 %. Pregnancy is the main risk factor for the development of SUI. This review provides details of the pathophysiology leading to SUI in pregnant women and SUI prevalence and treatment during pregnancy.

METHODS

We conducted a PubMed search for English-language and human-study articles registered from January 1990 to September 2012. This search was performed for articles dealing with prevalence and treatment of SUI during pregnancy. In the intervention studies, we included studies that used a randomized controlled trial (RCT) design or studies comparing a treatment intervention to no treatment.

RESULTS

A total of 534 articles were identified; 174 full-text articles were reviewed, and 28 of them met eligibility criteria and are reported on here. The mean prevalence of SUI during pregnancy was 41 % (18.6-60 %) and increased with gestational age. The increasing pressure of the growing uterus and fetal weight on pelvic-floor muscles (PFM) throughout pregnancy, together with pregnancy-related hormonal changes, may lead to reduced PFM strength as well as their supportive and sphincteric function. These cause mobility of the bladder neck and urethra, leading to urethral sphincter incompetence. Pelvic floor muscle exercise (PFME) is a safe and effective treatment for SUI during pregnancy, without significant adverse effects.

CONCLUSIONS

Understanding these issues can be useful for health-care professionals when informing and counseling pregnant women to help prevent SUI during pregnancy and the postpartum period.

Three-dimensional ultrasound of pelvic floor: is there a correlation with delivery mode and persisting pelvic floor disorders 18-24 months after first delivery?

OBJECTIVE

Three-dimensional (3D) transperineal ultrasound has been shown to be a reliable and reproducible method for visualization of morphological changes in the female levator ani muscle. The aim of this study was to evaluate the relationship between persisting pelvic floor disorders 18-24 months after first delivery, biometric measurements of the pelvic floor and mode of delivery.

METHODS

In this prospective observational study, we recruited on their second day after delivery 130 primiparous women. All were Caucasian and their pregnancies had been singleton with cephalic presentation. 3D transperineal ultrasound was performed, with standardized settings, on the second day (results published previously) and 18-24 months after delivery. Volumes were obtained at rest and on Valsalva maneuver and biometric measurements of the levator hiatus were determined in the axial plane. Obstetric and constitutional parameters were obtained from our clinical files and, 18-24 months after the delivery, a standardized questionnaire was used to evaluate persisting pelvic floor disorders. Ultrasound measurements at 18-24 months were compared according to clinical symptoms of pelvic floor disorders and mode of delivery, including a subgroup analysis of vaginal (spontaneous vs operative vaginal) and Cesarean (primary i.e. elective vs secondary i.e. after onset of labor) delivery groups.

RESULTS

Seventy-seven (59%) women had complete follow-up at 18-24 months. Biometric measurements showed a significantly larger hiatal area in the vaginal delivery group than in the Cesarean section group 2 years after delivery (P < 0.01), whereas subgroup analysis within the vaginal and Cesarean delivery groups did not show significant differences. Although there was no statistical correlation between delivery mode and persisting stress urinary incontinence, women with persisting stress urinary incontinence 2 years after delivery had a larger hiatal area than did women without this clinical symptom (P < 0.01). There were no significant differences in hiatal dimensions in women with bladder urgency or dyspareunia.

CONCLUSIONS

3D transperineal ultrasound, which is easily accessible, can provide useful information on morphological changes of the female pelvic floor. Women with a spontaneous or operative vaginal first delivery had a significantly larger hiatal area and axial distension than did women whose first delivery was by Cesarean section, even 2 years after delivery. Performing 3D ultrasound after the first delivery may help to identify women at high risk for persisting pelvic floor disorders.

Urinary incontinence in nulliparous women before and during pregnancy: prevalence, incidence, and associated risk factors

INTRODUCTION

Few studies have examined associations of prepregnancy urinary incontinence (UI).

METHODS

Multicentre prospective pregnancy cohort study (n = 1,507) using standardised measures to assess frequency and severity of UI.

RESULTS

Prevalence of UI increased from 10.8% in the 12 months before the index pregnancy to 55.9% in the third trimester. Stress incontinence (36.9%) and mixed incontinence (13.1%) were more common during pregnancy than urge incontinence alone (5.9%). UI before pregnancy was associated with childhood enuresis (adjusted odds ratio (AdjOR) = 2.4, 95% confidence interval (CI) 1.6-3.4), higher maternal body mass index (AdjOR = 2.3, 95% CI 1.4-3.8), and previous miscarriages or terminations (AdjOR = 1.6, 95% CI 1.1-2.3). The strongest predictor of incident UI in pregnancy was occasional leakage (less than once a month) before pregnancy (AdjOR = 3.6, 95% CI 2.8-4.7).

CONCLUSIONS

Further research is needed to elucidate the complex interplay of prepregnancy and pregnancy-related factors in the aetiology of UI in nulliparous women.

Urinary incontinence symptoms during and after pregnancy in continent and incontinent primiparas

OBJECTIVE

Examine patterns of urinary incontinence during and after pregnancy, as recalled by incontinent and continent primiparas.

STUDY DESIGN

Primiparous women reporting no pre-pregnancy incontinence, were recruited 6 to 9 months postpartum. Those reporting current continence and demonstrating a negative stress test were considered "Primiparous Continent" (PC, n=64). Those reporting current incontinence and demonstrating a positive stress test were considered "Primiparous Incontinent" (PI, n=57). Subjects self-administered a questionnaire recalling leakage during and after pregnancy.

RESULTS

Sixteen percent of PC women leaked during pregnancy. Of these, 70% experienced frequent leakage during pregnancy. Seventy-eight percent of PI women leaked both during and after pregnancy. Several patterns arose surrounding leakage frequency for PI women: 19% only leaked frequently during pregnancy, 4% only leaked frequently after pregnancy, and 51% leaked frequently both during and after pregnancy.

CONCLUSION

Nearly five times as many primiparous incontinent women, compared with primiparous continent women, leaked during pregnancy.

Prevalence and correlates of stress urinary incontinence during pregnancy: a survey at UNICAMP Medical School, São Paulo, Brazil

The aim of this study was to evaluate the prevalence of stress urinary incontinence (SUI) in women in the third trimester of pregnancy. In total, 340 patients attending the Antenatal Clinic at the State University of Campinas (UNICAMP) were interviewed. Overall, 170 women (50%) presented SUI. Stress urinary incontinence did not correlate to either body mass index (BMI) or race. There was no correlation between parity and SUI, but when considering distinct types of effort, urine leakage on coughing (P = 0.0478) and laughing (P = 0.0046) were highly more frequent in multiparous women. One hundred eleven women had had only vaginal deliveries and 68 delivered by cesarean section. There was no difference between the two groups concerning incontinence, but multiparous women (> or = 4) who delivered exclusively vaginally demonstrated 2.0 times more chances to leak urine when compared to nulliparous women. This fact strongly suggests parity to be more relevant than delivery route as a risk factor to stress urinary incontinence. Nulliparous women presented with a high percentage (45.5%) of the symptom, emphasizing the elevated risk of SUI during first pregnancy.

The effect of pregnancy and the oestrus cycle on purinergic and cholinergic responses of the rat urinary bladder

The urinary bladder undergoes plastic changes during physiological alterations such as pregnancy. This study has shown that bladders from pregnant rats weighed three times more than bladders from virgin rats. Each milligram of detrusor muscle from pregnant rats contracted more strongly to nerve stimulation (150% greater) and agonists (50% greater or more) compared to detrusor from virgin rats at any stage during the oestrus cycle. The purinergic component of nerve-mediated responses altered during the oestrus cycle, being greatest during oestrus (oestrogen and progesterone fall rapidly) and dioestrus (low oestrogen and progesterone), smaller during pregnancy and even smaller during pro-oestrus (high oestrogen and progesterone); in contrast the cholinergic component remained relatively unchanged. In conclusion, during pregnancy the detrusor muscle generates larger contractions compared to virgin detrusor muscle, probably due to hormonal influences on smooth muscle contraction mechanisms. As agonist responses were unchanged during the oestrus cycle, changes in the purinergic component of nerve stimulation was not due to altered P2 receptor expression but possibly to an increase in ATP release or a reduction in breakdown. The hormonal effect may have implications for the treatment of bladder disorders due to alterations in hormones, such as stress incontinence in post-menopausal women.